{"id":931,"date":"2025-04-21T20:53:53","date_gmt":"2025-04-21T12:53:53","guid":{"rendered":"https:\/\/eve2333.top\/?p=931"},"modified":"2025-04-21T20:53:53","modified_gmt":"2025-04-21T12:53:53","slug":"mysql%e6%95%b0%e6%8d%ae%e5%ba%93%e5%85%a5%e9%97%a8%e5%88%b0%e5%a4%a7%e8%9b%87%e5%b0%9a%e7%a1%85%e8%b0%b7%e5%ae%8b%e7%ba%a2%e5%ba%b7%e8%80%81%e5%b8%88%e7%ac%94%e8%ae%b0-%e9%ab%98%e7%ba%a7%e7%af%87-p-15","status":"publish","type":"post","link":"https:\/\/eve2333.top\/?p=931","title":{"rendered":"MySQL\u6570\u636e\u5e93\u5165\u95e8\u5230\u5927\u86c7\u5c1a\u7845\u8c37\u5b8b\u7ea2\u5eb7\u8001\u5e08\u7b14\u8bb0 \u9ad8\u7ea7\u7bc7 part15"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">\u7b2c15\u7ae0_\u9501<\/h1>\n\n\n\n<p>\u4e8b\u52a1\u7684<code>\u9694\u79bb\u6027<\/code>\u7531<code>\u9501<\/code>\u6765\u5b9e\u73b0<\/p>\n\n\n\n<p><code>\u9501<\/code>\u662f\u8ba1\u7b97\u673a\u534f\u8c03\u591a\u4e2a\u8fdb\u7a0b\u6216\u7ebf\u7a0b<code>\u5e76\u53d1\u8bbf\u95ee\u67d0\u4e00\u8d44\u6e90<\/code>\u7684\u673a\u5236\u3002\u5728\u7a0b\u5e8f\u5f00\u53d1\u4e2d\u4f1a\u5b58\u5728\u591a\u7ebf\u7a0b\u540c\u6b65\u7684\u95ee\u9898\uff0c\u5f53\u591a\u4e2a\u7ebf\u7a0b\u5e76\u53d1\u8bbf\u95ee\u67d0\u4e2a\u6570\u636e\u7684\u65f6\u5019\uff0c\u5c24\u5176\u662f\u9488\u5bf9\u4e00\u4e9b\u654f\u611f\u7684\u6570\u636e\uff08\u6bd4\u5982\u8ba2\u5355\u3001\u91d1\u989d\u7b49\uff09\uff0c\u6211\u4eec\u5c31\u9700\u8981\u4fdd\u8bc1\u8fd9\u4e2a\u6570\u636e\u5728\u4efb\u4f55\u65f6\u523b<code>\u6700\u591a\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b<\/code>\u5728\u8bbf\u95ee\uff0c\u4fdd\u8bc1\u6570\u636e\u7684<code>\u5b8c\u6574\u6027<\/code>\u548c<code>\u4e00\u81f4\u6027<\/code>\u3002\u5728\u5f00\u53d1\u8fc7\u7a0b\u4e2d\u52a0\u9501\u662f\u4e3a\u4e86\u4fdd\u8bc1\u6570\u636e\u7684\u4e00\u81f4\u6027\uff0c\u8fd9\u4e2a\u601d\u60f3\u5728\u6570\u636e\u5e93\u9886\u57df\u4e2d\u540c\u6837\u5f88\u91cd\u8981\u3002<\/p>\n\n\n\n<p>\u5728\u6570\u636e\u5e93\u4e2d\uff0c\u9664\u4f20\u7edf\u7684\u8ba1\u7b97\u8d44\u6e90\uff08\u5982CPU\u3001RAM\u3001I\/O\u7b49\uff09\u7684\u4e89\u7528\u4ee5\u5916\uff0c\u6570\u636e\u4e5f\u662f\u4e00\u79cd\u4f9b\u8bb8\u591a\u7528\u6237\u5171\u4eab\u7684\u8d44\u6e90\u3002\u4e3a\u4fdd\u8bc1\u6570\u636e\u7684\u4e00\u81f4\u6027\uff0c\u9700\u8981\u5bf9<code>\u5e76\u53d1\u64cd\u4f5c\u8fdb\u884c\u63a7\u5236<\/code>\uff0c\u56e0\u6b64\u4ea7\u751f\u4e86<code>\u9501<\/code>\u3002\u540c\u65f6<code>\u9501\u673a\u5236<\/code>\u4e5f\u4e3a\u5b9e\u73b0MySQL\u7684\u5404\u4e2a\u9694\u79bb\u7ea7\u522b\u63d0\u4f9b\u4e86\u4fdd\u8bc1\u3002<code>\u9501\u51b2\u7a81<\/code>\u4e5f\u662f\u5f71\u54cd\u6570\u636e\u5e93<code>\u5e76\u53d1\u8bbf\u95ee\u6027\u80fd<\/code>\u7684\u4e00\u4e2a\u91cd\u8981\u56e0\u7d20\u3002\u6240\u4ee5\u9501\u5bf9\u6570\u636e\u5e93\u800c\u8a00\u663e\u5f97\u5c24\u5176\u91cd\u8981\uff0c\u4e5f\u66f4\u52a0\u590d\u6742\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"2-mysql\u5e76\u53d1\u4e8b\u52a1\u8bbf\u95ee\u76f8\u540c\u8bb0\u5f55\">2. MySQL\u5e76\u53d1\u4e8b\u52a1\u8bbf\u95ee\u76f8\u540c\u8bb0\u5f55<\/h2>\n\n\n\n<p>\u5e76\u53d1\u4e8b\u52a1\u8bbf\u95ee\u76f8\u540c\u8bb0\u5f55\u7684\u60c5\u51b5\u5927\u81f4\u53ef\u4ee5\u5212\u5206\u4e3a3\u79cd\uff1a<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"21-\u8bfb-\u8bfb\u60c5\u51b5\">2.1 \u8bfb-\u8bfb\u60c5\u51b5<\/h3>\n\n\n\n<p><code>\u8bfb-\u8bfb<\/code>\u60c5\u51b5\uff0c\u5373\u5e76\u53d1\u4e8b\u52a1\u76f8\u7ee7<code>\u8bfb\u53d6\u76f8\u540c\u7684\u8bb0\u5f55<\/code>\u3002\u8bfb\u53d6\u64cd\u4f5c\u672c\u8eab\u4e0d\u4f1a\u5bf9\u8bb0\u5f55\u6709\u4efb\u4f55\u5f71\u54cd\uff0c\u5e76\u4e0d\u4f1a\u5f15\u8d77\u4ec0\u4e48\u95ee\u9898\uff0c\u6240\u4ee5\u5141\u8bb8\u8fd9\u79cd\u60c5\u51b5\u7684\u53d1\u751f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"22-\u5199-\u5199\u60c5\u51b5\">2.2 \u5199-\u5199\u60c5\u51b5<\/h3>\n\n\n\n<p><code>\u5199-\u5199<\/code>\u60c5\u51b5\uff0c\u5373\u5e76\u53d1\u4e8b\u52a1\u76f8\u7ee7\u5bf9\u76f8\u540c\u7684\u8bb0\u5f55\u505a\u51fa\u6539\u52a8\u3002<\/p>\n\n\n\n<p>\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u4f1a\u53d1\u751f<code>\u810f\u5199<\/code>\u7684\u95ee\u9898\uff0c\u4efb\u4f55\u4e00\u79cd\u9694\u79bb\u7ea7\u522b\u90fd\u4e0d\u5141\u8bb8\u8fd9\u79cd\u95ee\u9898\u7684\u53d1\u751f\u3002\u6240\u4ee5\u5728\u591a\u4e2a\u672a\u63d0\u4ea4\u4e8b\u52a1\u76f8\u7ee7\u5bf9\u4e00\u6761\u8bb0\u5f55\u505a\u6539\u52a8\u65f6\uff0c\u9700\u8981\u8ba9\u5b83\u4eec<code>\u6392\u961f\u6267\u884c<\/code>\uff0c\u8fd9\u4e2a\u6392\u961f\u7684\u8fc7\u7a0b\u5176\u5b9e\u662f\u901a\u8fc7\u9501\u6765\u5b9e\u73b0\u7684\u3002\u8fd9\u4e2a\u6240\u8c13\u7684\u9501\u5176\u5b9e\u662f\u4e00\u4e2a<code>\u5185\u5b58\u4e2d\u7684\u7ed3\u6784<\/code>\uff0c\u5728\u4e8b\u52a1\u6267\u884c\u524d\u672c\u6765\u662f\u6ca1\u6709\u9501\u7684\uff0c\u4e5f\u5c31\u662f\u8bf4\u4e00\u5f00\u59cb\u662f\u6ca1\u6709<code>\u9501\u7ed3\u6784<\/code>\u548c\u8bb0\u5f55\u8fdb\u884c\u5173\u8054\u7684\uff0c\u5982\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"98\" width=\"329\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/33c44fd9ee084a6b94552932ef4bb2fc.png\" alt=\"\"><\/p>\n\n\n\n<p>\u5f53\u4e00\u4e2a\u4e8b\u52a1\u60f3\u5bf9\u8fd9\u6761\u8bb0\u5f55\u505a\u6539\u52a8\u65f6\uff0c\u9996\u5148\u4f1a\u770b\u770b\u5185\u5b58\u4e2d\u6709\u6ca1\u6709\u4e0e\u8fd9\u6761\u8bb0\u5f55\u5173\u8054\u7684<code>\u9501\u7ed3\u6784<\/code>\uff0c\u5f53\u6ca1\u6709\u7684\u65f6\u5019\u5c31\u4f1a\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e00\u4e2a<code>\u9501\u7ed3\u6784<\/code>\u4e0e\u4e4b\u5173\u8054\u3002\u6bd4\u5982\uff0c\u4e8b\u52a1<code>T1<\/code>\u8981\u5bf9\u8fd9\u6761\u8bb0\u5f55\u505a\u6539\u52a8\uff0c\u5c31\u9700\u8981\u751f\u6210\u4e00\u4e2a<code>\u9501\u7ed3\u6784<\/code>\u4e0e\u4e4b\u5173\u8054\uff1a<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"187\" width=\"690\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/7a1430eb68b141ef8aed99eea0f7e8e3.png\" alt=\"\"><\/p>\n\n\n\n<p>\u5728\u9501\u7ed3\u6784\u91cc\u6709\u5f88\u591a\u4fe1\u606f\uff0c\u4e3a\u4e86\u7b80\u5316\u7406\u89e3\uff0c\u53ea\u628a\u4e24\u4e2a\u6bd4\u8f83\u91cd\u8981\u7684\u5c5e\u6027\u62ff\u4e86\u51fa\u6765:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>trx\u4fe1\u606f<\/code>:\u4ee3\u8868\u8fd9\u4e2a\u9501\u7ed3\u6784\u662f\u54ea\u4e2a\u4e8b\u52a1\u751f\u6210\u7684\u3002<\/li>\n\n\n\n<li><code>is_waiting<\/code>\u00a0:\u4ee3\u8868\u5f53\u524d\u4e8b\u52a1\u662f\u5426\u5728\u7b49\u5f85\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5f53\u4e8b\u52a1<code>T1<\/code>\u6539\u52a8\u4e86\u8fd9\u6761\u8bb0\u5f55\u540e\uff0c\u5c31\u751f\u6210\u4e86\u4e00\u4e2a<code>\u9501\u7ed3\u6784<\/code>\u4e0e\u8be5\u8bb0\u5f55\u5173\u8054\uff0c\u56e0\u4e3a\u4e4b\u524d\u6ca1\u6709\u522b\u7684\u4e8b\u52a1\u4e3a\u8fd9\u6761\u8bb0\u5f55\u52a0\u9501\uff0c\u6240\u4ee5<code>is_waiting<\/code>\u5c5e\u6027\u5c31\u662f<code>false<\/code>\uff0c\u6211\u4eec\u628a\u8fd9\u4e2a\u573a\u666f\u5c31\u79f0\u4e4b\u4e3a<code>\u83b7\u53d6\u9501\u6210\u529f<\/code>\uff0c\u6216\u8005<code>\u52a0\u9501\u6210\u529f<\/code>\uff0c\u7136\u540e\u5c31\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u64cd\u4f5c\u4e86\u3002<\/p>\n\n\n\n<p>\u5728\u4e8b\u52a1<code>T1<\/code>\u63d0\u4ea4\u4e4b\u524d\uff0c\u53e6\u4e00\u4e2a\u4e8b\u52a1<code>T2<\/code>\u4e5f\u60f3\u5bf9\u8be5\u8bb0\u5f55\u505a\u6539\u52a8\uff0c\u90a3\u4e48\u5148\u770b\u770b\u6709\u6ca1\u6709\u9501\u7ed3\u6784\u4e0e\u8fd9\u6761\u8bb0\u5f55\u5173\u8054\uff0c\u53d1\u73b0\u6709\u4e00\u4e2a\u9501\u7ed3\u6784\u4e0e\u4e4b\u5173\u8054\u540e\uff0c\u7136\u540e\u4e5f\u751f\u6210\u4e86\u4e00\u4e2a\u9501\u7ed3\u6784\u4e0e\u8fd9\u6761\u8bb0\u5f55\u5173\u8054\uff0c\u4e0d\u8fc7\u9501\u7ed3\u6784\u7684<code>is_waiting<\/code>\u5c5e\u6027\u503c\u4e3a<code>true<\/code>&nbsp;,\u8868\u793a\u5f53\u524d\u4e8b\u52a1\u9700\u8981\u7b49\u5f85\uff0c\u6211\u4eec\u628a\u8fd9\u4e2a\u573a\u666f\u5c31\u79f0\u4e4b\u4e3a<code>\u83b7\u53d6\u9501\u5931<\/code>\u8d25\uff0c\u6216\u8005<code>\u52a0\u9501\u5931\u8d25<\/code>\uff0c\u56fe\u793a:<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"402\" width=\"1037\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/89efea88ac8740aa8ba9a2582932ba8f.png\" alt=\"\"><\/p>\n\n\n\n<p>\u5728\u4e8b\u52a1T1\u63d0\u4ea4\u4e4b\u540e\uff0c\u5c31\u4f1a\u628a\u8be5\u4e8b\u52a1\u751f\u6210\u7684<code>\u9501\u7ed3\u6784\u91ca\u653e<\/code>\u6389\uff0c\u7136\u540e\u770b\u770b\u8fd8\u6709\u6ca1\u6709\u522b\u7684\u4e8b\u52a1\u5728\u7b49\u5f85\u83b7\u53d6\u9501\uff0c\u53d1\u73b0\u4e86\u4e8b\u52a1T2\u8fd8\u5728\u7b49\u5f85\u83b7\u53d6\u9501\uff0c\u6240\u4ee5\u628a\u4e8b\u52a1T2\u5bf9\u5e94\u7684\u9501\u7ed3\u6784\u7684<code>is_waiting<\/code>\u5c5e\u6027\u8bbe\u7f6e\u4e3a<code>false<\/code>\uff0c\u7136\u540e\u628a\u8be5\u4e8b\u52a1\u5bf9\u5e94\u7684\u7ebf\u7a0b\u5524\u9192\uff0c\u8ba9\u5b83\u7ee7\u7eed\u6267\u884c\uff0c\u6b64\u65f6\u4e8b\u52a1T2\u5c31\u7b97\u83b7\u53d6\u5230\u9501\u4e86\u3002\u6548\u679c\u56fe\u5c31\u662f\u8fd9\u6837:<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"192\" width=\"643\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/b6b15cea5ca14d6d8fb7108ab751868a.png\" alt=\"\"><\/p>\n\n\n\n<p>\u5c0f\u7ed3\u51e0\u79cd\u8bf4\u6cd5\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e0d\u52a0\u9501 \u610f\u601d\u5c31\u662f\u4e0d\u9700\u8981\u5728\u5185\u5b58\u4e2d\u751f\u6210\u5bf9\u5e94\u7684<code>\u9501\u7ed3\u6784<\/code>\uff0c\u53ef\u4ee5\u76f4\u63a5\u6267\u884c\u64cd\u4f5c\u3002<\/li>\n\n\n\n<li>\u83b7\u53d6\u9501\u6210\u529f\uff0c\u6216\u8005\u52a0\u9501\u6210\u529f \u610f\u601d\u5c31\u662f\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e86\u5bf9\u5e94\u7684<code>\u9501\u7ed3\u6784<\/code>\uff0c\u800c\u4e14\u9501\u7ed3\u6784\u7684<code>is_waiting<\/code>\u5c5e\u6027\u4e3a<code>false<\/code>\uff0c\u4e5f\u5c31\u662f\u4e8b\u52a1<br>\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u64cd\u4f5c\u3002<\/li>\n\n\n\n<li>\u83b7\u53d6\u9501\u5931\u8d25\uff0c\u6216\u8005\u52a0\u9501\u5931\u8d25\uff0c\u6216\u8005\u6ca1\u6709\u83b7\u53d6\u5230\u9501 \u610f\u601d\u5c31\u662f\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e86\u5bf9\u5e94\u7684\u9501\u7ed3\u6784\uff0c\u4e0d\u8fc7\u9501\u7ed3\u6784\u7684<code>is_waiting<\/code>\u5c5e\u6027\u4e3a<code>true<\/code>\uff0c\u4e5f\u5c31\u662f\u4e8b\u52a1<br>\u9700\u8981\u7b49\u5f85\uff0c\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"23-\u8bfb-\u5199\u6216\u5199-\u8bfb\u60c5\u51b5\">2.3 \u8bfb-\u5199\u6216\u5199-\u8bfb\u60c5\u51b5<\/h3>\n\n\n\n<p><code>\u8bfb-\u5199<\/code>\u6216<code>\u5199-\u8bfb<\/code>\uff0c\u5373\u4e00\u4e2a\u4e8b\u52a1\u8fdb\u884c\u8bfb\u53d6\u64cd\u4f5c\uff0c\u53e6\u4e00\u4e2a\u8fdb\u884c\u6539\u52a8\u64cd\u4f5c\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ef\u80fd\u53d1\u751f<code>\u810f\u8bfb<\/code>\u3001<code>\u4e0d\u53ef\u91cd\u590d\u8bfb<\/code>\u3001<code>\u5e7b\u8bfb<\/code>\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n<p>\u5404\u4e2a\u6570\u636e\u5e93\u5382\u5546\u5bf9<code>SQL\u6807\u51c6\u7684<\/code>\u652f\u6301\u90fd\u53ef\u80fd\u4e0d\u4e00\u6837\u3002\u6bd4\u5982MySQL\u5728<code>REPEATABLE READ<\/code>\u9694\u79bb\u7ea7\u522b\u4e0a\u5c31\u5df2\u7ecf\u89e3\u51b3\u4e86\u5e7b\u8bfb\u95ee\u9898\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"24-\u5e76\u53d1\u95ee\u9898\u7684\u89e3\u51b3\u65b9\u6848\">2.4 \u5e76\u53d1\u95ee\u9898\u7684\u89e3\u51b3\u65b9\u6848<\/h3>\n\n\n\n<p>\u600e\u4e48\u89e3\u51b3<code>\u810f\u8bfb<\/code>\u3001<code>\u4e0d\u53ef\u91cd\u590d\u8bfb<\/code>\u3001<code>\u5e7b\u8bfb<\/code>\u8fd9\u4e9b\u95ee\u9898\u5462\uff1f\u5176\u5b9e\u6709\u4e24\u79cd\u53ef\u9009\u7684\u89e3\u51b3\u65b9\u6848\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u65b9\u6848\u4e00\uff1a\u8bfb\u64cd\u4f5c\u5229\u7528\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\uff08<code>MVCC<\/code>\uff0c\u4e0b\u7ae0\u8bb2\u89e3\uff09\uff0c\u5199\u64cd\u4f5c\u8fdb\u884c<code>\u52a0\u9501<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u6240\u8c13\u7684<code>MVCC<\/code>\uff0c\u5c31\u662f\u751f\u6210\u4e00\u4e2a<code>ReadView<\/code>\uff0c\u901a\u8fc7ReadView\u627e\u5230\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55\u7248\u672c\uff08\u5386\u53f2\u7248\u672c\u7531<code>undo\u65e5\u5fd7<\/code>\u6784\u5efa\uff09\u3002\u67e5\u8be2\u8bed\u53e5\u53ea\u80fd<code>\u8bfb<\/code>\u5230\u5728\u751f\u6210ReadView\u4e4b\u524d<code>\u5df2\u63d0\u4ea4\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539<\/code>\uff0c\u5728\u751f\u6210ReadView\u4e4b\u524d\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u6216\u8005\u4e4b\u540e\u624d\u5f00\u542f\u7684\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539\u662f\u770b\u4e0d\u5230\u7684\u3002\u800c<code>\u5199\u64cd\u4f5c<\/code>\u80af\u5b9a\u9488\u5bf9\u7684\u662f<code>\u6700\u65b0\u7248\u672c\u7684\u8bb0\u5f55<\/code>\uff0c\u8bfb\u8bb0\u5f55\u7684\u5386\u53f2\u7248\u672c\u548c\u6539\u52a8\u8bb0\u5f55\u7684\u6700\u65b0\u7248\u672c\u672c\u8eab\u5e76\u4e0d\u51b2\u7a81\uff0c\u4e5f\u5c31\u662f\u91c7\u7528MVCC\u65f6\uff0c<code>\u8bfb-\u5199<\/code>\u64cd\u4f5c\u5e76\u4e0d\u51b2\u7a81\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u666e\u901a\u7684SELECT\u8bed\u53e5\u5728READ COMMITTED\u548cREPEATABLE READ\u9694\u79bb\u7ea7\u522b\u4e0b\u4f1a\u4f7f\u7528\u5230MVCC\u8bfb\u53d6\u8bb0\u5f55\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5728<code>READ COMMITTED<\/code>\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u4e00\u4e2a\u4e8b\u52a1\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\u6bcf\u6b21\u6267\u884cSELECT\u64cd\u4f5c\u65f6\u90fd\u4f1a\u751f\u6210\u4e00\u4e2aReadView\uff0cReadView\u7684\u5b58\u5728\u672c\u8eab\u5c31\u4fdd\u8bc1\u4e86<code>\u4e8b\u52a1\u4e0d\u53ef\u4ee5\u8bfb\u53d6\u5230\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u6240\u505a\u7684\u66f4\u6539<\/code>\uff0c\u4e5f\u5c31\u662f\u907f\u514d\u4e86\u810f\u8bfb\u73b0\u8c61\uff1b<\/li>\n\n\n\n<li>\u5728<code>REPEATABLE READ<\/code>\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u4e00\u4e2a\u4e8b\u52a1\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\u53ea\u6709<code>\u7b2c\u4e00\u6b21\u6267\u884cSELECT\u64cd\u4f5c<\/code>\u624d\u4f1a\u751f\u6210\u4e00\u4e2aReadView\uff0c\u4e4b\u540e\u7684SELECT\u64cd\u4f5c\u90fd<code>\u590d\u7528<\/code>\u8fd9ReadView\uff0c\u8fd9\u6837\u4e5f\u5c31\u907f\u514d\u4e86\u4e0d\u53ef\u91cd\u590d\u8bfb\u548c\u5e7b\u8bfb\u7684\u95ee\u9898\u3002<\/li>\n<\/ul>\n<\/blockquote>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u65b9\u6848\u4e8c\uff1a\u8bfb\u3001\u5199\u64cd\u4f5c\u90fd\u91c7\u7528<code>\u52a0\u9501<\/code>\u7684\u65b9\u5f0f\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5982\u679c\u6211\u4eec\u7684\u4e00\u4e9b\u4e1a\u52a1\u573a\u666f\u4e0d\u5141\u8bb8\u8bfb\u53d6\u8bb0\u5f55\u7684\u65e7\u7248\u672c\uff0c\u800c\u662f\u6bcf\u6b21\u90fd\u5fc5\u987b\u53bb<code>\u8bfb\u53d6\u8bb0\u5f55\u7684\u6700\u65b0\u7248\u672c<\/code>\u3002\u6bd4\u5982\uff0c\u5728\u94f6\u884c\u5b58\u6b3e\u7684\u4e8b\u52a1\u4e2d\uff0c\u4f60\u9700\u8981\u5148\u628a\u8d26\u6237\u7684\u4f59\u989d\u8bfb\u51fa\u6765\uff0c\u7136\u540e\u5c06\u5176\u52a0\u4e0a\u672c\u6b21\u5b58\u6b3e\u7684\u6570\u989d\u6700\u540e\u518d\u5199\u5230\u6570\u636e\u5e93\u4e2d\u3002\u5728\u5c06\u8d26\u6237\u4f59\u989d\u8bfb\u53d6\u51fa\u6765\u540e\uff0c\u5c31\u4e0d\u60f3\u8ba9\u522b\u7684\u4e8b\u52a1\u518d\u8bbf\u95ee\u8be5\u4f59\u989d\uff0c\u76f4\u5230\u672c\u6b21\u5b58\u6b3e\u4e8b\u52a1\u6267\u884c\u5b8c\u6210\uff0c\u5176\u4ed6\u4e8b\u52a1\u624d\u53ef\u4ee5\u8bbf\u95ee\u8d26\u6237\u7684\u4f59\u989d\u3002\u8fd9\u6837\u5728\u8bfb\u53d6\u8bb0\u5f55\u7684\u65f6\u5019\u5c31\u9700\u8981\u5bf9\u5176\u8fdb\u884c<code>\u52a0\u9501<\/code>\u64cd\u4f5c\uff0c\u8fd9\u6837\u4e5f\u5c31\u610f\u5473\u7740<code>\u8bfb<\/code>\u64cd\u4f5c\u548c<code>\u5199<\/code>\u64cd\u4f5c\u4e5f\u50cf<code>\u5199-\u5199<\/code>\u64cd\u4f5c\u90a3\u6837<code>\u6392\u961f<\/code>\u6267\u884c\u3002<\/p>\n\n\n\n<p><code>\u810f\u8bfb<\/code>\u7684\u4ea7\u751f\u662f\u56e0\u4e3a\u5f53\u524d\u4e8b\u52a1\u8bfb\u53d6\u4e86\u53e6\u4e00\u4e2a\u672a\u63d0\u4ea4\u4e8b\u52a1\u5199\u7684\u4e00\u6761\u8bb0\u5f55\uff0c\u5982\u679c\u53e6\u4e00\u4e2a\u4e8b\u52a1\u5728\u5199\u8bb0\u5f55\u7684\u65f6\u5019\u5c31\u7ed9\u8fd9\u6761\u8bb0\u5f55\u52a0\u9501\uff0c\u90a3\u4e48\u5f53\u524d\u4e8b\u52a1\u5c31\u65e0\u6cd5\u7ee7\u7eed\u8bfb\u53d6\u8be5\u8bb0\u5f55\u4e86\uff0c\u6240\u4ee5\u4e5f\u5c31\u4e0d\u4f1a\u6709\u810f\u8bfb\u95ee\u9898\u7684\u4ea7\u751f\u4e86\u3002<\/p>\n\n\n\n<p><code>\u4e0d\u53ef\u91cd\u590d\u8bfb<\/code>\u7684\u4ea7\u751f\u662f\u56e0\u4e3a\u5f53\u524d\u4e8b\u52a1\u5148\u8bfb\u53d6\u4e00\u6761\u8bb0\u5f55\uff0c\u53e6\u5916\u4e00\u4e2a\u4e8b\u52a1\u5bf9\u8be5\u8bb0\u5f55\u505a\u4e86\u6539\u52a8\u4e4b\u540e\u5e76\u63d0\u4ea4\u4e4b\u540e\uff0c\u5f53\u524d\u4e8b\u52a1\u518d\u6b21\u8bfb\u53d6\u65f6\u4f1a\u83b7\u5f97\u4e0d\u540c\u7684\u503c\uff0c\u5982\u679c\u5728\u5f53\u524d\u4e8b\u52a1\u8bfb\u53d6\u8bb0\u5f55\u65f6\u5c31\u7ed9\u8be5\u8bb0\u5f55\u52a0\u9501\u90a3\u4e48\u53e6\u4e00\u4e2a\u4e8b\u52a1\u5c31\u65e0\u6cd5\u4fee\u6539\u8be5\u8bb0\u5f55\uff0c\u81ea\u7136\u4e5f\u4e0d\u4f1a\u53d1\u751f\u4e0d\u53ef\u91cd\u590d\u8bfb\u4e86\u3002<\/p>\n\n\n\n<p><code>\u5e7b\u8bfb<\/code>\u95ee\u9898\u7684\u4ea7\u751f\u662f\u56e0\u4e3a\u5f53\u524d\u4e8b\u52a1\u8bfb\u53d6\u4e86\u4e00\u4e2a\u8303\u56f4\u7684\u8bb0\u5f55\uff0c\u7136\u540e\u53e6\u5916\u7684\u4e8b\u52a1\u5411\u8be5\u8303\u56f4\u5185\u63d2\u5165\u4e86\u65b0\u8bb0\u5f55\uff0c\u5f53\u524d\u4e8b\u52a1\u518d\u6b21\u8bfb\u53d6\u8be5\u8303\u56f4\u7684\u8bb0\u5f55\u65f6\u53d1\u73b0\u4e86\u65b0\u63d2\u5165\u7684\u65b0\u8bb0\u5f55\u3002\u91c7\u7528\u52a0\u9501\u7684\u65b9\u5f0f\u89e3\u51b3\u5e7b\u8bfb\u95ee\u9898\u5c31\u6709\u4e00\u4e9b\u9ebb\u70e6\uff0c\u56e0\u4e3a\u5f53\u524d\u4e8b\u52a1\u5728\u7b2c\u4e00\u6b21\u8bfb\u53d6\u8bb0\u5f55\u65f6\u5e7b\u5f71\u8bb0\u5f55\u5e76\u4e0d\u5b58\u5728\uff0c\u6240\u4ee5\u8bfb\u53d6\u7684\u65f6\u5019\u52a0\u9501\u5c31\u6709\u70b9\u5c34\u5c2c\uff08\u56e0\u4e3a\u4f60\u5e76\u4e0d\u77e5\u9053\u7ed9\u8c01\u52a0\u9501)\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5c0f\u7ed3\u5bf9\u6bd4\u53d1\u73b0\uff1a\n<ul class=\"wp-block-list\">\n<li>\u91c7\u7528<code>MVCC<\/code>\u65b9\u5f0f\u7684\u8bdd\uff0c<code>\u8bfb-\u5199<\/code>\u64cd\u4f5c\u5f7c\u6b64\u5e76\u4e0d\u51b2\u7a81\uff0c<code>\u6027\u80fd\u66f4\u9ad8<\/code>\u3002<\/li>\n\n\n\n<li>\u91c7\u7528<code>\u52a0\u9501<\/code>\u65b9\u5f0f\u7684\u8bdd\uff0c<code>\u8bfb-\u5199<\/code>\u64cd\u4f5c\u5f7c\u6b64\u9700\u8981<code>\u6392\u961f\u6267\u884c<\/code>\uff0c\u5f71\u54cd\u6027\u80fd\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u4e00\u822c\u60c5\u51b5\u4e0b\u6211\u4eec\u5f53\u7136\u613f\u610f\u91c7\u7528<code>MVCC<\/code>\u6765\u89e3\u51b3<code>\u8bfb-\u5199<\/code>\u64cd\u4f5c\u5e76\u53d1\u6267\u884c\u7684\u95ee\u9898\uff0c\u4f46\u662f\u4e1a\u52a1\u5728\u67d0\u4e9b\u7279\u6b8a\u60c5\u51b5\u4e0b\uff0c\u8981\u6c42\u5fc5\u987b\u91c7\u7528<code>\u52a0\u9501<\/code>\u7684\u65b9\u5f0f\u6267\u884c\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u9488\u5bf9<strong>\u5feb\u7167\u8bfb<\/strong>\uff08\u666e\u901a select \u8bed\u53e5\uff09\uff0c\u662f\u901a\u8fc7&nbsp;<strong>MVCC \u65b9\u5f0f\u89e3\u51b3\u4e86\u5e7b\u8bfb<\/strong>\u3002\u56e0\u4e3a\u53ef\u91cd\u590d\u8bfb\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u770b\u5230\u7684\u6570\u636e\uff0c\u4e00\u76f4\u8ddf\u8fd9\u4e2a\u4e8b\u52a1\u542f\u52a8\u65f6\u770b\u5230\u7684\u6570\u636e\u662f\u4e00\u81f4\u7684\uff0c\u5373\u4f7f\u4e2d\u9014\u6709\u5176\u4ed6\u4e8b\u52a1\u63d2\u5165\u4e86\u4e00\u6761\u6570\u636e\uff0c\u67e5\u8be2\u4e0d\u51fa\u6765\u8fd9\u6761\u6570\u636e\u7684\uff0c\u6240\u4ee5\u5c31\u5f88\u597d\u4e86\u907f\u514d\u5e7b\u8bfb\u95ee\u9898\u3002<\/p>\n\n\n\n<p>\u9488\u5bf9<strong>\u5f53\u524d\u8bfb<\/strong>\uff08select \u2026 for update \u7b49\u8bed\u53e5\uff09\uff0c\u662f\u901a\u8fc7&nbsp;<strong>next-key lock\uff08\u8bb0\u5f55\u9501 + \u95f4\u9699\u9501\uff09\u65b9\u5f0f\u89e3\u51b3\u4e86\u5e7b\u8bfb<\/strong>\u3002\u56e0\u4e3a\u5f53\u6267\u884c select \u2026 for update \u8bed\u53e5\u7684\u65f6\u5019\uff0c\u4f1a\u52a0\u4e0a next-key lock\uff0c\u5982\u679c\u6709\u5176\u4ed6\u4e8b\u52a1\u5728 next-key lock \u9501\u8303\u56f4\u5185\u63d2\u5165\u4e86\u4e00\u6761\u8bb0\u5f55\uff0c\u90a3\u4e48\u8fd9\u4e2a\u63d2\u5165\u8bed\u53e5\u5c31\u4f1a\u88ab\u963b\u585e\uff0c\u65e0\u6cd5\u6210\u529f\u63d2\u5165\uff0c\u6240\u4ee5\u5c31\u5f88\u597d\u4e86\u907f\u514d\u5e7b\u8bfb\u95ee\u9898\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"3-\u9501\u7684\u4e0d\u540c\u89d2\u5ea6\u5206\u7c7b\">3. \u9501\u7684\u4e0d\u540c\u89d2\u5ea6\u5206\u7c7b<\/h2>\n\n\n\n<p>\u9501\u7684\u5206\u7c7b\u56fe\uff0c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"839\" width=\"670\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/0a4cd1a437c0420bbe0924da851e8293.png\" alt=\"\"><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"31-\u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c7b\u578b\u5212\u5206\u8bfb\u9501-\u5199\u9501\">3.1 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c7b\u578b\u5212\u5206\uff1a\u8bfb\u9501\u3001\u5199\u9501<\/h3>\n\n\n\n<p>\u5bf9\u4e8e\u6570\u636e\u5e93\u4e2d\u5e76\u53d1\u4e8b\u52a1\u7684<code>\u8bfb-\u8bfb<\/code>\u60c5\u51b5\u5e76\u4e0d\u4f1a\u5f15\u8d77\u4ec0\u4e48\u95ee\u9898\u3002\u5bf9\u4e8e<code>\u5199-\u5199<\/code>\u3001<code>\u8bfb-\u5199<\/code>\u6216<code>\u5199-\u8bfb<\/code>\u8fd9\u4e9b\u60c5\u51b5\u53ef\u80fd\u4f1a\u5f15\u8d77\u4e00\u4e9b\u95ee\u9898\uff0c\u9700\u8981\u4f7f\u7528<code>MVCC<\/code>\u6216\u8005<code>\u52a0\u9501<\/code>\u7684\u65b9\u5f0f\u6765\u89e3\u51b3\u5b83\u4eec\u3002\u5728\u4f7f\u7528<code>\u52a0\u9501<\/code>\u7684\u65b9\u5f0f\u89e3\u51b3\u95ee\u9898\u65f6\uff0c\u7531\u4e8e\u65e2\u8981\u5141\u8bb8<code>\u8bfb-\u8bfb<\/code>\u60c5\u51b5\u4e0d\u53d7\u5f71\u54cd\uff0c\u53c8\u8981\u4f7f<code>\u5199-\u5199<\/code>\u3001<code>\u8bfb-\u5199<\/code>\u6216<code>\u5199-\u8bfb<\/code>\u60c5\u51b5\u4e2d\u7684\u64cd\u4f5c\u76f8\u4e92\u963b\u585e\uff0c\u6240\u4ee5MySQL\u5b9e\u73b0\u4e00\u4e2a\u7531\u4e24\u79cd\u7c7b\u578b\u7684\u9501\u7ec4\u6210\u7684\u9501\u7cfb\u7edf\u6765\u89e3\u51b3\u3002\u8fd9\u4e24\u79cd\u7c7b\u578b\u7684\u9501\u901a\u5e38\u88ab\u79f0\u4e3a<strong>\u5171\u4eab\u9501(Shared Lock\uff0cSLock)\u548c\u6392\u4ed6\u9501(Exclusive Lock\uff0cXLock),\u4e5f\u53eb\u8bfb\u9501(readlock)\u548c\u5199\u9501(write lock)<\/strong>\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>\u8bfb\u9501<\/code>\uff1a\u4e5f\u79f0\u4e3a<code>\u5171\u4eab\u9501<\/code>\u3001\u82f1\u6587\u7528<code>S<\/code>\u8868\u793a\u3002\u9488\u5bf9\u540c\u4e00\u4efd\u6570\u636e\uff0c\u591a\u4e2a\u4e8b\u52a1\u7684\u8bfb\u64cd\u4f5c\u53ef\u4ee5\u540c\u65f6\u8fdb\u884c\u800c\u4e0d\u4f1a\u4e92\u76f8\u5f71\u54cd\uff0c\u76f8\u4e92\u4e0d\u963b\u585e\u7684\u3002<\/li>\n\n\n\n<li><code>\u5199\u9501<\/code>\uff1a\u4e5f\u79f0\u4e3a<code>\u6392\u4ed6\u9501<\/code>\u3001\u82f1\u6587\u7528<code>X<\/code>\u8868\u793a\u3002\u5f53\u524d\u5199\u64cd\u4f5c\u6ca1\u6709\u5b8c\u6210\u524d\uff0c\u5b83\u4f1a\u963b\u65ad\u5176\u4ed6\u5199\u9501\u548c\u8bfb\u9501\u3002\u8fd9\u6837\u5c31\u80fd\u786e\u4fdd\u5728\u7ed9\u5b9a\u7684\u65f6\u95f4\u91cc\uff0c\u53ea\u6709\u4e00\u4e2a\u4e8b\u52a1\u80fd\u6267\u884c\u5199\u5165\uff0c\u5e76\u9632\u6b62\u5176\u4ed6\u7528\u6237\u8bfb\u53d6\u6b63\u5728\u5199\u5165\u7684\u540c\u4e00\u8d44\u6e90\u3002<\/li>\n<\/ul>\n\n\n\n<p><strong>\u9700\u8981\u6ce8\u610f\u7684\u662f\u5bf9\u4e8e InnoDB \u5f15\u64ce\u6765\u8bf4\uff0c\u8bfb\u9501\u548c\u5199\u9501\u53ef\u4ee5\u52a0\u5728\u8868\u4e0a\uff0c\u4e5f\u53ef\u4ee5\u52a0\u5728\u884c\u4e0a\u3002<\/strong><\/p>\n\n\n\n<p><strong>\u4e3e\u4f8b(\u884c\u7ea7\u8bfb\u5199\u9501)\u2236<\/strong>\u5982\u679c\u4e00\u4e2a\u4e8b\u52a1T1\u5df2\u7ecf\u83b7\u5f97\u4e86\u67d0\u4e2a\u884cr\u7684\u8bfb\u9501\uff0c\u90a3\u4e48\u6b64\u65f6\u53e6\u5916\u7684\u4e00\u4e2a\u4e8b\u52a1T2\u662f\u53ef\u4ee5\u53bb\u83b7\u5f97\u8fd9\u4e2a\u884cr\u7684\u8bfb\u9501\u7684\uff0c\u56e0\u4e3a\u8bfb\u53d6\u64cd\u4f5c\u5e76\u6ca1\u6709\u6539\u53d8\u884cr\u7684\u6570\u636e;\u4f46\u662f\uff0c\u5982\u679c\u67d0\u4e2a\u4e8b\u52a1T3\u60f3\u83b7\u5f97\u884cr\u7684\u5199\u9501\uff0c\u5219\u5b83\u5fc5\u987b\u7b49\u5f85\u4e8b\u52a1T1\u3001T2\u91ca\u653e\u6389\u884cr\u4e0a\u7684\u8bfb\u9501\u624d\u884c\u3002<\/p>\n\n\n\n<p>\u603b\u7ed3:\u8fd9\u91cc\u7684\u517c\u5bb9\u662f\u6307\u5bf9\u540c\u4e00\u5f20\u8868\u6216\u8bb0\u5f55\u7684\u9501\u7684\u517c\u5bb9\u6027\u60c5\u51b5\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><\/th><th>X\u9501<\/th><th>S\u9501<\/th><\/tr><\/thead><tbody><tr><td>X\u9501<\/td><td>\u4e0d\u517c\u5bb9<\/td><td>\u4e0d\u517c\u5bb9<\/td><\/tr><tr><td>S\u9501<\/td><td>\u4e0d\u517c\u5bb9<\/td><td><strong>\u517c\u5bb9<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"1\u9501\u5b9a\u8bfb\">1\uff09\u9501\u5b9a\u8bfb<\/h4>\n\n\n\n<p>\u5728\u91c7\u7528<code>\u52a0\u9501<\/code>\u65b9\u5f0f\u89e3\u51b3<code>\u810f\u8bfb<\/code>\u3001<code>\u4e0d\u53ef\u91cd\u590d\u8bfb<\/code>\u3001<code>\u5e7b\u8bfb<\/code>\u8fd9\u4e9b\u95ee\u9898\u65f6\uff0c\u8bfb\u53d6\u4e00\u6761\u8bb0\u5f55\u65f6\u9700\u8981\u83b7\u53d6\u8be5\u8bb0\u5f55\u7684<code>S\u9501<\/code>\uff0c\u5176\u5b9e\u662f\u4e0d\u4e25\u8c28\u7684\uff0c\u6709\u65f6\u5019\u9700\u8981\u5728\u8bfb\u53d6\u8bb0\u5f55\u65f6\u5c31\u83b7\u53d6\u8bb0\u5f55\u7684<code>X\u9501<\/code>\uff0c\u6765\u7981\u6b62\u522b\u7684\u4e8b\u52a1\u8bfb\u5199\u8be5\u8bb0\u5f55\uff0c\u4e3a\u6b64MySQL\u63d0\u51fa\u4e86\u4e24\u79cd\u6bd4\u8f83\u7279\u6b8a\u7684<code>SELECT<\/code>\u8bed\u53e5\u683c\u5f0f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5bf9\u8bfb\u53d6\u7684\u8bb0\u5f55\u52a0<code>S\u9501<\/code>\uff1a<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT ... LOCK IN SHARE MODE;\n# \u6216\nSELECT ... FOR SHARE; # (8.0\u65b0\u589e\u8bed\u6cd5)\n<\/code><\/pre>\n\n\n\n<p>\u5728\u666e\u901a\u7684SELECT\u8bed\u53e5\u540e\u8fb9\u52a0<code>LOCK IN SHARE MODE<\/code>\uff0c\u5982\u679c\u5f53\u524d\u4e8b\u52a1\u6267\u884c\u4e86\u8be5\u8bed\u53e5\uff0c\u90a3\u4e48\u5b83\u4f1a\u4e3a\u8bfb\u53d6\u5230\u7684\u8bb0\u5f55\u52a0S\u9501\uff0c\u8fd9\u6837\u5141\u8bb8\u522b\u7684\u4e8b\u52a1\u7ee7\u7eed\u83b7\u53d6\u8fd9\u4e9b\u8bb0\u5f55\u7684S\u9501(\u6bd4\u65b9\u8bf4\u522b\u7684\u4e8b\u52a1\u4e5f\u4f7f\u7528<code>SELECT ... LOCK IN SHAREMODE<\/code>\u8bed\u53e5\u6765\u8bfb\u53d6\u8fd9\u4e9b\u8bb0\u5f55)\uff0c\u4f46\u662f\u4e0d\u80fd\u83b7\u53d6\u8fd9\u4e9b\u8bb0\u5f55\u7684<code>X\u9501<\/code>(\u6bd4\u5982\u4f7f\u7528<code>SELECT ... FOR UPDATE<\/code>\u8bed\u53e5\u6765\u8bfb\u53d6\u8fd9\u4e9b\u8bb0\u5f55\uff0c\u6216\u8005\u76f4\u63a5\u4fee\u6539\u8fd9\u4e9b\u8bb0\u5f55)\u3002\u5982\u679c\u522b\u7684\u4e8b\u52a1\u60f3\u8981\u83b7\u53d6\u8fd9\u4e9b\u8bb0\u5f55\u7684<code>X\u9501<\/code>\uff0c\u90a3\u4e48\u5b83\u4eec\u4f1a\u963b\u585e\uff0c\u76f4\u5230\u5f53\u524d\u4e8b\u52a1\u63d0\u4ea4\u4e4b\u540e\u5c06\u8fd9\u4e9b\u8bb0\u5f55\u4e0a\u7684<code>S\u9501<\/code>\u91ca\u653e\u6389\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5bf9\u8bfb\u53d6\u7684\u8bb0\u5f55\u52a0<code>X\u9501<\/code>\uff1a<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT ... FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u5728\u666e\u901a\u7684SELECT\u8bed\u53e5\u540e\u8fb9\u52a0<code>FOR UPDATE<\/code>\uff0c\u5982\u679c\u5f53\u524d\u4e8b\u52a1\u6267\u884c\u4e86\u8be5\u8bed\u53e5\uff0c\u90a3\u4e48\u5b83\u4f1a\u4e3a\u8bfb\u53d6\u5230\u7684\u8bb0\u5f55\u52a0<code>X\u9501<\/code>\uff0c\u8fd9\u6837\u65e2\u4e0d\u5141\u8bb8\u522b\u7684\u4e8b\u52a1\u83b7\u53d6\u8fd9\u4e9b\u8bb0\u5f55\u7684S\u9501(\u6bd4\u65b9\u8bf4\u522b\u7684\u4e8b\u52a1\u4f7f\u7528<code>SELECT ... LOCK IN SHARE MODE<\/code>\u8bed\u53e5\u6765\u8bfb\u53d6\u8fd9\u4e9b\u8bb0\u5f55)\uff0c\u4e5f\u4e0d\u5141\u8bb8\u83b7\u53d6\u8fd9\u4e9b\u8bb0\u5f55\u7684X\u9501(\u6bd4\u5982\u4f7f\u7528<code>SELECT ... FOR UPDATE<\/code>\u8bed\u53e5\u6765\u8bfb\u53d6\u8fd9\u4e9b\u8bb0\u5f55\uff0c\u6216\u8005\u76f4\u63a5\u4fee\u6539\u8fd9\u4e9b\u8bb0\u5f55)\u3002\u5982\u679c\u522b\u7684\u4e8b\u52a1\u60f3\u8981\u83b7\u53d6\u8fd9\u4e9b\u8bb0\u5f55\u7684S\u9501\u6216\u8005X\u9501\uff0c\u90a3\u4e48\u5b83\u4eec\u4f1a\u963b\u585e\uff0c\u76f4\u5230\u5f53\u524d\u4e8b\u52a1\u63d0\u4ea4\u4e4b\u540e\u5c06\u8fd9\u4e9b\u8bb0\u5f55\u4e0a\u7684X\u9501\u91ca\u653e\u6389\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"mysql80\u65b0\u7279\u6027nowait-skip-locked\">MySQL8.0\u65b0\u7279\u6027\uff1aNOWAIT\u3001SKIP LOCKED<\/h5>\n\n\n\n<p>\u57285.7\u53ca\u4e4b\u524d\u7684\u7248\u672c\uff0c<code>SELECT ... FOR UPDATE<\/code>\uff0c\u5982\u679c\u83b7\u53d6\u4e0d\u5230\u9501\uff0c\u4f1a\u4e00\u76f4\u7b49\u5f85\uff0c\u76f4\u5230<code>innodb_lock_wait_timeout<\/code>\u8d85\u65f6\u3002\u57288.0\u7248\u672c\u4e2d\uff0c<code>SELECT ... FOR UPDATE<\/code>,&nbsp;<code>SELECT ... FOR SHARE<\/code>&nbsp;\u53ef\u4ee5\u901a\u8fc7\u6dfb\u52a0<code>NOWAIT<\/code>\u3001<code>SKIP LOCKED<\/code>\u8bed\u6cd5\uff0c\u8df3\u8fc7\u9501\u7b49\u5f85\uff0c\u6216\u8005\u8df3\u8fc7\u9501\u5b9a\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NOWAIT\uff1a\u5982\u679c\u67e5\u8be2\u7684\u884c\u5df2\u7ecf\u52a0\u9501\uff0c\u4f1a\u7acb\u5373\u62a5\u9519\u8fd4\u56de<\/li>\n\n\n\n<li>SKIP LOCKED\uff1a\u5982\u679c\u67e5\u8be2\u7684\u884c\u5df2\u7ecf\u52a0\u9501\uff0c\u53ea\u8fd4\u56de\u7ed3\u679c\u4e2d\u4e0d\u5305\u542b\u88ab\u9501\u5b9a\u7684\u884c<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code># session1:\nmysql&gt; begin;\nmysql&gt; select * from t1 where c1 = 2 for update;\n+----+------+\n| c1 | c2   |\n+----+------+\n| 2  | 60530|\n| 2  | 24678|\n+----+------+\n2 rows in set (0.00 sec)\n\n# session2:\nmysql&gt; select * from t1 where c1 = 2 for update nowait;\nERROR 3572 (HY000): Statement aborted because lock(s) could not be acquired immediately and NOWAIT is set.\n\nmysql&gt; select * from t1 where c1 = 2 for update skip locked;\nEmpty set (0.00 sec)\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"2\u5199\u64cd\u4f5c\">2\uff09\u5199\u64cd\u4f5c<\/h4>\n\n\n\n<p>\u5e73\u5e38\u6240\u7528\u5230\u7684<code>\u5199\u64cd\u4f5c<\/code>\u65e0\u975e\u662f<code>DELETE<\/code>\u3001<code>UPDATE<\/code>\u3001<code>INSERT<\/code>\u8fd9\u4e09\u79cd:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>DELETE<\/code>:<br>\u5bf9\u4e00\u6761\u8bb0\u5f55\u505aDELETE\u64cd\u4f5c\u7684\u8fc7\u7a0b\u5176\u5b9e\u662f\u5148\u5728<code>B+<\/code>\u6811\u4e2d\u5b9a\u4f4d\u5230\u8fd9\u6761\u8bb0\u5f55\u7684\u4f4d\u7f6e\uff0c\u7136\u540e\u83b7\u53d6\u8fd9\u6761\u8bb0\u5f55\u7684<code>X\u9501<\/code>\uff0c\u518d\u6267\u884c<code>delete mark<\/code>\u64cd\u4f5c\u3002\u6211\u4eec\u4e5f\u53ef\u4ee5\u628a\u8fd9\u4e2a\u5b9a\u4f4d\u5f85\u5220\u9664\u8bb0\u5f55\u5728B+\u6811\u4e2d\u4f4d\u7f6e\u7684\u8fc7\u7a0b\u770b\u6210\u662f\u4e00\u4e2a\u83b7\u53d6<code>X\u9501<\/code>\u7684<code>\u9501\u5b9a\u8bfb<\/code>\u3002<\/li>\n\n\n\n<li><code>UPDATE<\/code>\u2236\u5728\u5bf9\u4e00\u6761\u8bb0\u5f55\u505aUPDATE\u64cd\u4f5c\u65f6\u5206\u4e3a\u4e09\u79cd\u60c5\u51b5:\n<ul class=\"wp-block-list\">\n<li>\u60c5\u51b51: \u672a\u4fee\u6539\u8be5\u8bb0\u5f55\u7684<code>\u952e\u503c<\/code>\uff0c\u5e76\u4e14\u88ab\u66f4\u65b0\u7684\u5217\u5360\u7528\u7684\u5b58\u50a8\u7a7a\u95f4\u5728\u4fee\u6539\u524d\u540e<code>\u672a\u53d1\u751f\u53d8\u5316<\/code>\u3002 \u5219\u5148\u5728<code>B+<\/code>\u6811\u4e2d\u5b9a\u4f4d\u5230\u8fd9\u6761\u8bb0\u5f55\u7684\u4f4d\u7f6e\uff0c\u7136\u540e\u518d\u83b7\u53d6\u4e00\u4e0b\u8bb0\u5f55\u7684<code>X\u9501<\/code>\uff0c\u6700\u540e\u5728\u539f\u8bb0\u5f55\u7684\u4f4d\u7f6e\u8fdb\u884c\u4fee\u6539\u64cd\u4f5c\u3002\u6211\u4eec\u4e5f\u53ef\u4ee5\u628a\u8fd9\u4e2a\u5b9a\u4f4d\u5f85\u4fee\u6539\u8bb0\u5f55\u5728B+\u6811\u4e2d\u4f4d\u7f6e\u7684\u8fc7\u7a0b\u770b\u6210\u662f\u4e00\u4e2a\u83b7\u53d6<code>X\u9501<\/code>\u7684<code>\u9501\u5b9a\u8bfb<\/code>\u3002<\/li>\n\n\n\n<li>\u60c5\u51b52\u2236\u672a\u4fee\u6539\u8be5\u8bb0\u5f55\u7684<code>\u952e\u503c<\/code>\uff0c\u5e76\u4e14\u81f3\u5c11\u6709\u4e00\u4e2a\u88ab\u66f4\u65b0\u7684\u5217\u5360\u7528\u7684\u5b58\u50a8\u7a7a\u95f4\u5728\u4fee\u6539\u524d\u540e\u53d1\u751f\u53d8\u5316\u3002 \u5219\u5148\u5728B+\u6811\u4e2d\u5b9a\u4f4d\u5230\u8fd9\u6761\u8bb0\u5f55\u7684\u4f4d\u7f6e\uff0c\u7136\u540e\u83b7\u53d6\u4e00\u4e0b\u8bb0\u5f55\u7684X\u9501\uff0c\u5c06\u8be5\u8bb0\u5f55\u5f7b\u5e95\u5220\u9664\u6389\uff08\u5c31\u662f\u628a\u8bb0\u5f55\u5f7b\u5e95\u79fb\u5165\u5783\u573e\u94fe\u8868)\uff0c\u6700\u540e\u518d\u63d2\u5165\u4e00\u6761\u65b0\u8bb0\u5f55\u3002\u8fd9\u4e2a\u5b9a\u4f4d\u5f85\u4fee\u6539\u8bb0\u5f55\u5728B+\u6811\u4e2d\u4f4d\u7f6e\u7684\u8fc7\u7a0b\u53ef\u4ee5\u770b\u6210\u662f\u4e00\u4e2a\u83b7\u53d6<code>X\u9501<\/code>\u7684<code>\u9501\u5b9a\u8bfb<\/code>\uff0c\u65b0\u63d2\u5165\u7684\u8bb0\u5f55\u7531<code>INSERT<\/code>\u64cd\u4f5c\u63d0\u4f9b\u7684<code>\u9690\u5f0f\u9501<\/code>\u8fdb\u884c\u4fdd\u62a4\u3002<\/li>\n\n\n\n<li>\u60c5\u51b53\u2236\u4fee\u6539\u4e86\u8be5\u8bb0\u5f55\u7684\u952e\u503c\uff0c\u5219\u76f8\u5f53\u4e8e\u5728\u539f\u8bb0\u5f55\u4e0a\u505a<code>DELETE<\/code>\u64cd\u4f5c\u4e4b\u540e\u518d\u6765\u4e00\u6b21<code>INSERT<\/code>\u64cd\u4f5c\uff0c\u52a0\u9501\u64cd\u4f5c\u5c31\u9700\u8981\u6309\u7167<code>DELETE<\/code>\u548c<code>INSERT<\/code>\u7684\u89c4\u5219\u8fdb\u884c\u4e86\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><code>INSERT<\/code>: \u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u65b0\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\u7684\u64cd\u4f5c\u5e76\u4e0d\u52a0\u9501\uff0c\u901a\u8fc7\u4e00\u79cd\u79f0\u4e4b\u4e3a<code>\u9690\u5f0f\u9501<\/code>\u7684\u7ed3\u6784\u6765\u4fdd\u62a4\u8fd9\u6761\u65b0\u63d2\u5165\u7684\u8bb0\u5f55\u5728\u672c\u4e8b\u52a1<code>\u63d0\u4ea4\u524d\u4e0d\u88ab\u522b\u7684\u4e8b\u52a1\u8bbf\u95ee<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"32-\u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\u8868\u7ea7\u9501-\u9875\u7ea7\u9501-\u884c\u9501\">3.2 \u4ece\u6570\u636e\u64cd\u4f5c\u7684\u7c92\u5ea6\u5212\u5206\uff1a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u3001\u884c\u9501<\/h3>\n\n\n\n<p>\u4e3a\u4e86\u5c3d\u53ef\u80fd\u63d0\u9ad8\u6570\u636e\u5e93\u7684\u5e76\u53d1\u5ea6\uff0c\u6bcf\u6b21\u9501\u5b9a\u7684\u6570\u636e\u8303\u56f4\u8d8a\u5c0f\u8d8a\u597d\uff0c\u7406\u8bba\u4e0a\u6bcf\u6b21\u53ea\u9501\u5b9a\u5f53\u524d\u64cd\u4f5c\u7684\u6570\u636e\u7684\u65b9\u6848\u4f1a\u5f97\u5230\u6700\u5927\u7684\u5e76\u53d1\u5ea6\uff0c\u4f46\u662f\u7ba1\u7406\u9501\u662f\u5f88<code>\u8017\u8d44\u6e90<\/code>\u7684\u4e8b\u60c5\uff08\u6d89\u53ca\u83b7\u53d6\u3001\u68c0\u67e5\u3001\u91ca\u653e\u9501\u7b49\u52a8\u4f5c)(\u8d8a\u5c0f\u6d88\u8017\u8d8a\u5927)\u3002\u56e0\u6b64\u6570\u636e\u5e93\u7cfb\u7edf\u9700\u8981\u5728<code>\u9ad8\u5e76\u54cd\u5e94<\/code>\u548c<code>\u7cfb\u7edf\u6027\u80fd<\/code>\u4e24\u65b9\u9762\u8fdb\u884c\u5e73\u8861\uff0c\u8fd9\u6837\u5c31\u4ea7\u751f\u4e86\u201c<code>\u9501\u7c92\u5ea6(Lock granularity)<\/code>\u201d\u7684\u6982\u5ff5\u3002<\/p>\n\n\n\n<p>\u5bf9\u4e00\u6761\u8bb0\u5f55\u52a0\u9501\u5f71\u54cd\u7684\u4e5f\u53ea\u662f\u8fd9\u6761\u8bb0\u5f55\u800c\u5df2\uff0c\u6211\u4eec\u5c31\u8bf4\u8fd9\u4e2a\u9501\u7684\u7c92\u5ea6\u6bd4\u8f83\u7ec6;\u5176\u5b9e\u4e00\u4e2a\u4e8b\u52a1\u4e5f\u53ef\u4ee5\u5728<code>\u8868\u7ea7\u522b<\/code>\u8fdb\u884c\u52a0\u9501\uff0c\u81ea\u7136\u5c31\u88ab\u79f0\u4e4b\u4e3a<code>\u8868\u7ea7\u9501<\/code>\u6216\u8005<code>\u8868\u9501<\/code>\uff0c\u5bf9\u4e00\u4e2a\u8868\u52a0\u9501\u5f71\u54cd\u6574\u4e2a\u8868\u4e2d\u7684\u8bb0\u5f55\uff0c\u6211\u4eec\u5c31\u8bf4\u8fd9\u4e2a\u9501\u7684\u7c92\u5ea6\u6bd4\u8f83\u7c97\u3002\u9501\u7684\u7c92\u5ea6\u4e3b\u8981\u5206\u4e3a\u8868\u7ea7\u9501\u3001\u9875\u7ea7\u9501\u548c\u884c\u9501\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"321-\u8868\u9501table-lock\">3.2.1 \u8868\u9501\uff08Table Lock\uff09<\/h4>\n\n\n\n<p>\u8be5\u9501\u4f1a\u9501\u5b9a\u6574\u5f20\u8868\uff0c\u5b83\u662fMySQL\u4e2d\u6700\u57fa\u672c\u7684\u9501\u7b56\u7565\uff0c\u5e76<code>\u4e0d\u4f9d\u8d56\u4e8e\u5b58\u50a8\u5f15\u64ce<\/code>\uff0c\u5e76\u4e14\u8868\u9501\u662f<code>\u5f00\u9500\u6700\u5c11<\/code>\u7684\u7b56\u7565\uff08\u56e0\u4e3a\u7c92\u5ea6\u6bd4\u8f83\u5927)\u3002\u7531\u4e8e\u8868\u7ea7\u9501\u4e00\u6b21\u4f1a\u5c06\u6574\u4e2a\u8868\u9501\u5b9a\uff0c\u6240\u4ee5\u53ef\u4ee5\u5f88\u597d\u7684<code>\u907f\u514d\u6b7b\u9501<\/code>\u7684\u95ee\u9898\u3002\u5f53\u7136\uff0c\u9501\u7684\u7c92\u5ea6\u5927\u6240\u5e26\u6765\u6700\u5927\u7684\u8d1f\u9762\u5f71\u54cd\u5c31\u662f\u51fa\u73b0\u9501\u8d44\u6e90\u4e89\u7528\u7684\u6982\u7387\u4e5f\u4f1a\u6700\u9ad8\uff0c\u5bfc\u81f4<code>\u5e76\u53d1\u7387\u5927\u6253\u6298\u6263<\/code>\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"1-\u8868\u7ea7\u522b\u7684s\u9501-x\u9501\">\u2460 \u8868\u7ea7\u522b\u7684S\u9501\u3001X\u9501<\/h5>\n\n\n\n<p>\u5728\u5bf9\u67d0\u4e2a\u8868\u6267\u884cSELECT\u3001INSERT\u3001DELETE\u3001UPDATE\u8bed\u53e5\u65f6\uff0cInnoDB\u5b58\u50a8\u5f15\u64ce\u662f\u4e0d\u4f1a\u4e3a\u8fd9\u4e2a\u8868\u6dfb\u52a0\u8868\u7ea7\u522b\u7684<code>S\u9501<\/code>\u6216\u8005<code>X\u9501<\/code>\u7684\u3002\u5728\u5bf9\u67d0\u4e2a\u8868\u6267\u884c\u4e00\u4e9b\u8bf8\u5982<code>ALTER TABLE<\/code>\u3001<code>DROP TABLE<\/code>\u8fd9\u7c7b\u7684<code>DDL<\/code>\u8bed\u53e5\u65f6\uff0c\u5176\u4ed6\u4e8b\u52a1\u5bf9\u8fd9\u4e2a\u8868\u5e76\u53d1\u6267\u884c\u8bf8\u5982SELECT\u3001INSERT\u3001DELETE\u3001UPDATE\u7684\u8bed\u53e5\u4f1a\u53d1\u751f\u963b\u585e\u3002\u540c\u7406\uff0c\u67d0\u4e2a\u4e8b\u52a1\u4e2d\u5bf9\u67d0\u4e2a\u8868\u6267\u884cSELECT\u3001INSERT\u3001DELETE\u3001UPDATE\u8bed\u53e5\u65f6\uff0c\u5728\u5176\u4ed6\u4f1a\u8bdd\u4e2d\u5bf9\u8fd9\u4e2a\u8868\u6267\u884c<code>DDL<\/code>\u8bed\u53e5\u4e5f\u4f1a\u53d1\u751f\u963b\u585e\u3002\u8fd9\u4e2a\u8fc7\u7a0b\u5176\u5b9e\u662f\u901a\u8fc7\u5728<code>server\u5c42<\/code>\u4f7f\u7528\u4e00\u79cd\u79f0\u4e4b\u4e3a<code>\u5143\u6570\u636e\u9501<\/code>\uff08\u82f1\u6587\u540d\uff1a<code>Metadata Locks<\/code>\uff0c\u7b80\u79f0<code>MDL<\/code>\uff09\u7ed3\u6784\u6765\u5b9e\u73b0\u7684\u3002<\/p>\n\n\n\n<p>\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u4e0d\u4f1a\u4f7f\u7528InnoDB\u5b58\u50a8\u5f15\u64ce\u63d0\u4f9b\u7684\u8868\u7ea7\u522b\u7684<code>S\u9501<\/code>\u548c<code>X\u9501<\/code>\u3002\u53ea\u4f1a\u5728\u4e00\u4e9b\u7279\u6b8a\u60c5\u51b5\u4e0b\uff0c\u6bd4\u65b9\u8bf4<code>\u5d29\u6e83\u6062\u590d<\/code>\u8fc7\u7a0b\u4e2d\u7528\u5230\u3002\u5fc5\u987b\u5148\u8bbe\u7f6e\u7cfb\u7edf\u53d8\u91cf<code>autocommit=0\uff0cinnodb_table_locks = 1<\/code>\uff0cInnoDB\u5b58\u50a8\u5f15\u64ce\u624d\u80fd\u8bc6\u522bMySQL\u6dfb\u52a0\u7684\u8868\u7ea7\u9501\uff0c\u624b\u52a8\u83b7\u53d6InnoDB\u5b58\u50a8\u5f15\u64ce\u63d0\u4f9b\u7684\u8868t\u7684<code>S\u9501<\/code>\u6216\u8005<code>X\u9501<\/code>\u53ef\u4ee5\u8fd9\u4e48\u5199\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>LOCK TABLES t READ<\/code>\uff1aInnoDB\u5b58\u50a8\u5f15\u64ce\u4f1a\u5bf9\u8868<code>t<\/code>\u52a0\u8868\u7ea7\u522b\u7684<code>S\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK TABLES t WRITE<\/code>\uff1aInnoDB\u5b58\u50a8\u5f15\u64ce\u4f1a\u5bf9\u8868<code>t<\/code>\u52a0\u8868\u7ea7\u522b\u7684<code>X\u9501<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u4e0d\u8fc7\u5c3d\u91cf\u907f\u514d\u5728\u4f7f\u7528InnoDB\u5b58\u50a8\u5f15\u64ce\u7684\u8868\u4e0a\u4f7f\u7528<code>LOCK TABLES<\/code>\u8fd9\u6837\u7684\u624b\u52a8\u9501\u8868\u8bed\u53e5\uff0c\u5b83\u4eec\u5e76\u4e0d\u4f1a\u63d0\u4f9b\u4ec0\u4e48\u989d\u5916\u7684\u4fdd\u62a4\uff0c\u53ea\u662f\u4f1a\u964d\u4f4e\u5e76\u53d1\u80fd\u529b\u800c\u5df2\u3002InnoDB\u7684\u5389\u5bb3\u4e4b\u5904\u8fd8\u662f\u5728\u4e8e\u5b9e\u73b0\u4e86\u66f4\u7ec6\u7c92\u5ea6\u7684\u884c\u9501\uff0c\u5173\u4e8eInnoDB\u8868\u7ea7\u522b\u7684S\u9501\u548cX\u9501\u4e86\u89e3\u4e00\u4e0b\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n\n\n\n<p><strong>\u4e3e\u4f8b\uff1a\u4e0b\u9762\u6211\u4eec\u8bb2\u89e3MyISAM\u5f15\u64ce\u4e0b\u7684\u8868\u9501\u3002<\/strong><\/p>\n\n\n\n<p>\u6b65\u9aa41\uff1a\u521b\u5efa\u8868\u5e76\u6dfb\u52a0\u6570\u636e<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE TABLE mylock(\n  id INT NOT NULL PRIMARY KEY auto_increment,\n  NAME VARCHAR(20)\n)ENGINE myisam; # \u5b58\u50a8\u5f15\u64ce\u4f7f\u7528 InnoDB \u4e5f\u53ef\u4ee5, \u53ea\u662f\u4e0d\u5efa\u8bae\n\n# \u63d2\u5165\u4e00\u6761\u6570\u636e\nINSERT INTO mylock(NAME) VALUES('a');\n\n# \u67e5\u8be2\u8868\u4e2d\u6240\u6709\u7684\u6570\u636e\nSELECT * FROM mylock;\n+----+------+\n| id | NAME |\n+----+------+\n|  1 | a    |\n+----+------+\n<\/code><\/pre>\n\n\n\n<p>\u6b65\u9aa42\uff1a\u67e5\u770b\u8868\u4e0a\u52a0\u8fc7\u7684\u9501<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SHOW OPEN TABLES;  # \u4e3b\u8981\u5173\u6ce8 In_use \u5b57\u6bb5\u7684\u503c\n# \u6216\u8005\nSHOW OPEN TABLES where In_use &gt; 0;\n<\/code><\/pre>\n\n\n\n<p>\u6b65\u9aa43\uff1a\u624b\u52a8\u589e\u52a0\u8868\u9501\u547d\u4ee4<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>LOCK TABLES t READ;  # \u5b58\u50a8\u5f15\u64ce\u4f1a\u5bf9\u8868t\u52a0\u8868\u7ea7\u522b\u7684\u5171\u4eab\u9501\u3002\u5171\u4eab\u9501\u4e5f\u53eb\u8bfb\u9501\u6216 S \u9501 (Share\u7684\u7f29\u5199)\nLOCK TABLES t WRITE;  \n# \u5b58\u50a8\u5f15\u64ce\u4f1a\u5bf9\u8868t\u52a0\u8868\u7ea7\u522b\u7684\u6392\u4ed6\u9501\u3002\u6392\u4ed6\u9501\u4e5f\u53eb\u72ec\u5360\u9501\u3001\u5199\u9501\u6216 X \u9501 (\u662feXclusive\u7684\u7f29\u5199)\n<\/code><\/pre>\n\n\n\n<p>\u6bd4\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql&gt; lock tables mylock write;\nQuery OK, 0 rows affected (0.00 sec)\n\nmysql&gt; SHOW OPEN TABLES where In_use &gt; 0;\n+------------+--------+--------+-------------+\n| Database   | Table  | In_use | Name_locked |\n+------------+--------+--------+-------------+\n| atguigu14  | mylock | 1      | 0           |\n+------------+--------+--------+-------------+\n<\/code><\/pre>\n\n\n\n<p>\u6b65\u9aa44\uff1a\u91ca\u653e\u8868\u9501<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>UNLOCK TABLES; # \u4f7f\u7528\u6b64\u547d\u4ee4\u89e3\u9501\u5f53\u524d\u52a0\u9501\u7684\u8868\n<\/code><\/pre>\n\n\n\n<p>\u6bd4\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql&gt; unlock tables;\nQuery OK, 0 rows affected (0.01 \u79d2)\n\n# \u53ef\u4ee5\u770b\u5230\u5df2\u7ecf\u6ca1\u6709 In_use &gt; 0 \u7684\u6570\u636e\u4e86\nmysql&gt; SHOW OPEN TABLES where In_use &gt; 0;\n<\/code><\/pre>\n\n\n\n<p>\u6b65\u9aa45\uff1a\u52a0\u8bfb\u9501<\/p>\n\n\n\n<p>\u6211\u4eec\u4e3amylock\u8868\u52a0\u4e0aread\u9501\uff08\u8bfb\u963b\u585e\u5199\uff09\uff0c\u89c2\u5bdf\u963b\u585e\u7684\u60c5\u51b5\uff0c\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"946\" src=\"https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239985-image-1024x946.png\" alt=\"\" class=\"wp-image-934\" srcset=\"https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239985-image-1024x946.png 1024w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239985-image-300x277.png 300w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239985-image-768x709.png 768w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239985-image.png 1166w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>\u6b65\u9aa46\uff1a\u52a0\u5199\u9501<\/p>\n\n\n\n<p>\u4e3amylock\u8868\u52a0\u4e0awrite\u9501\uff0c\u89c2\u5bdf\u963b\u585e\u7684\u60c5\u51b5\uff0c\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"981\" height=\"1024\" src=\"https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239977-image-981x1024.png\" alt=\"\" class=\"wp-image-933\" srcset=\"https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239977-image-981x1024.png 981w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239977-image-287x300.png 287w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239977-image-768x802.png 768w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239977-image.png 1133w\" sizes=\"auto, (max-width: 981px) 100vw, 981px\" \/><\/figure>\n\n\n\n<p>MyISAM\u5b58\u50a8\u5f15\u64ce\u7684\u8868\u5728\u6267\u884c\u67e5\u8be2\u8bed\u53e5\u524d\uff0c\u4f1a\u81ea\u52a8\u7ed9\u6d89\u53ca\u7684\u6240\u6709\u8868\u52a0\u8bfb\u9501\uff0c\u5728\u6267\u884c\u589e\u5220\u6539\u64cd\u4f5c\u524d\uff0c\u4f1a\u81ea\u52a8\u7ed9\u6d89\u53ca\u7684\u8868\u52a0\u5199\u9501\u3002\u7528\u6237\u4e00\u822c\u4e0d\u9700\u8981\u76f4\u63a5\u4f7f\u7528LOCK TABLES\u8bed\u53e5\u6765\u663e\u5f0f\u52a0\u9501\u3002<\/p>\n\n\n\n<p><code>InnoDB<\/code>\u5b58\u50a8\u5f15\u64ce\u662f\u4e0d\u4f1a\u4e3a\u8fd9\u4e2a\u8868\u6dfb\u52a0\u8868\u7ea7\u522b\u7684<code>\u8bfb\u9501<\/code>\u6216\u8005<code>\u5199\u9501<\/code>\u7684\u3002<\/p>\n\n\n\n<p>MySQL\u7684\u8868\u7ea7\u9501\u6709\u4e24\u79cd\u6a21\u5f0f\uff1a\uff08\u4ee5MyISAM\u8868\u8fdb\u884c\u64cd\u4f5c\u7684\u6f14\u793a\uff09<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8868\u5171\u4eab\u8bfb\u9501\uff08Table Read Lock\uff09<\/li>\n\n\n\n<li>\u8868\u72ec\u5360\u5199\u9501\uff08Table Write Lock\uff09<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u9501\u7c7b\u578b<\/th><th>\u81ea\u5df1\u53ef\u8bfb<\/th><th>\u81ea\u5df1\u53ef\u5199<\/th><th>\u81ea\u5df1\u53ef\u64cd\u4f5c\u5176\u4ed6\u8868<\/th><th>\u4ed6\u4eba\u53ef\u8bfb<\/th><th>\u4ed6\u4eba\u53ef\u5199<\/th><\/tr><\/thead><tbody><tr><td>\u8bfb\u9501<\/td><td>\u662f<\/td><td>\u5426<\/td><td>\u5426<\/td><td>\u662f<\/td><td>\u5426\uff0c\u7b49<\/td><\/tr><tr><td>\u5199\u9501<\/td><td>\u662f<\/td><td>\u662f<\/td><td>\u5426<\/td><td>\u5426\uff0c\u7b49<\/td><td>\u5426\uff0c\u7b49<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"2-\u610f\u5411\u9501-intention-lock\">\u2461 \u610f\u5411\u9501 \uff08intention lock\uff09<\/h5>\n\n\n\n<p>InnoDB \u652f\u6301<code>\u591a\u7c92\u5ea6\u9501\uff08multiple granularity locking\uff09<\/code>\uff0c\u5b83\u5141\u8bb8<code>\u884c\u7ea7\u9501<\/code>\u4e0e<code>\u8868\u7ea7\u9501<\/code>\u5171\u5b58\uff0c\u800c<strong>\u610f\u5411\u9501<\/strong>\u5c31\u662f\u5176\u4e2d\u7684\u4e00\u79cd<code>\u8868\u9501<\/code>\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u610f\u5411\u9501\u7684\u5b58\u5728\u662f\u4e3a\u4e86\u534f\u8c03\u884c\u9501\u548c\u8868\u9501\u7684\u5173\u7cfb\uff0c\u652f\u6301\u591a\u7c92\u5ea6\uff08\u8868\u9501\u4e0e\u884c\u9501\uff09\u7684\u9501\u5e76\u5b58\u3002<\/li>\n\n\n\n<li>\u610f\u5411\u9501\u662f\u4e00\u79cd<code>\u4e0d\u4e0e\u884c\u7ea7\u9501\u51b2\u7a81\u7684\u8868\u7ea7\u9501<\/code>\uff0c\u8fd9\u4e00\u70b9\u975e\u5e38\u91cd\u8981\u3002<\/li>\n\n\n\n<li>\u8868\u660e\u201c\u67d0\u4e2a\u4e8b\u52a1\u6b63\u5728\u67d0\u4e9b\u884c\u6301\u6709\u4e86\u9501\u6216\u8be5\u4e8b\u52a1\u51c6\u5907\u53bb\u6301\u6709\u9501\u201d<\/li>\n<\/ul>\n\n\n\n<p><strong>\u610f\u5411\u9501\u5206\u4e3a\u4e24\u79cd\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u610f\u5411\u5171\u4eab\u9501<\/strong>\uff08intention shared lock, IS\uff09\uff1a\u4e8b\u52a1\u6709\u610f\u5411\u5bf9\u8868\u4e2d\u7684\u67d0\u4e9b\u884c\u52a0<strong>\u5171\u4eab\u9501<\/strong>\uff08S\u9501\uff09<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>-- \u4e8b\u52a1\u8981\u83b7\u53d6\u67d0\u4e9b\u884c\u7684 S \u9501\uff0c\u5fc5\u987b\u5148\u83b7\u5f97\u8868\u7684 IS \u9501\u3002 \nSELECT column FROM table ... LOCK IN SHARE MODE;\n<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u610f\u5411\u6392\u4ed6\u9501<\/strong>\uff08intention exclusive lock, IX\uff09\uff1a\u4e8b\u52a1\u6709\u610f\u5411\u5bf9\u8868\u4e2d\u7684\u67d0\u4e9b\u884c\u52a0<strong>\u6392\u4ed6\u9501<\/strong>\uff08X\u9501\uff09<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>-- \u4e8b\u52a1\u8981\u83b7\u53d6\u67d0\u4e9b\u884c\u7684 X \u9501\uff0c\u5fc5\u987b\u5148\u83b7\u5f97\u8868\u7684 IX \u9501\u3002 \nSELECT column FROM table ... FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u5373\uff1a\u610f\u5411\u9501\u662f\u7531\u5b58\u50a8\u5f15\u64ce<code>\u81ea\u5df1\u7ef4\u62a4\u7684<\/code>\uff0c\u7528\u6237\u65e0\u6cd5\u624b\u52a8\u64cd\u4f5c\u610f\u5411\u9501\uff0c\u5728\u4e3a\u6570\u636e\u884c\u52a0\u5171\u4eab \/ \u6392\u4ed6\u9501\u4e4b\u524d\uff0cInooDB \u4f1a\u5148\u83b7\u53d6\u8be5\u6570\u636e\u884c<code>\u6240\u5728\u6570\u636e\u8868\u7684\u5bf9\u5e94\u610f\u5411\u9501<\/code>\u3002<\/p>\n\n\n\n<p><strong>\u610f\u5411\u9501\u8981\u89e3\u51b3\u7684\u95ee\u9898<\/strong><\/p>\n\n\n\n<p>\u73b0\u5728\u6709\u4e24\u4e2a\u4e8b\u52a1\uff0c\u5206\u522b\u662fT1\u548cT2\uff0c\u5176\u4e2dT2\u8bd5\u56fe\u5728\u8be5\u8868\u7ea7\u522b\u4e0a\u5e94\u7528\u5171\u4eab\u6216\u6392\u5b83\u9501\uff0c\u5982\u679c\u6ca1\u6709\u610f\u5411\u9501\u5b58\u5728\uff0c\u90a3\u4e48T2\u5c31\u9700\u8981\u53bb\u68c0\u67e5\u5404\u4e2a\u9875\u6216\u884c\u662f\u5426\u5b58\u5728\u9501\uff1b\u5982\u679c\u5b58\u5728\u610f\u5411\u9501\uff0c\u90a3\u4e48\u6b64\u65f6\u5c31\u4f1a\u53d7\u5230\u7531T1\u63a7\u5236\u7684<code>\u8868\u7ea7\u522b\u610f\u5411\u9501\u7684\u963b\u585e<\/code>\u3002T2\u5728\u9501\u5b9a\u8be5\u8868\u524d\u4e0d\u5fc5\u68c0\u67e5\u5404\u4e2a\u9875\u6216\u884c\u9501\uff0c\u800c\u53ea\u9700\u68c0\u67e5\u8868\u4e0a\u7684\u610f\u5411\u9501\u3002\u7b80\u5355\u6765\u8bf4\u5c31\u662f\u7ed9\u66f4\u5927\u4e00\u7ea7\u7ea7\u522b\u7684\u7a7a\u95f4\u793a\u610f\u91cc\u9762\u662f\u5426\u5df2\u7ecf\u4e0a\u8fc7\u9501\u3002<\/p>\n\n\n\n<p>\u5728\u6570\u636e\u8868\u7684\u573a\u666f\u4e2d\uff0c<strong>\u5982\u679c\u6211\u4eec\u7ed9\u67d0\u4e00\u884c\u6570\u636e\u52a0\u4e0a\u4e86\u6392\u5b83\u9501\uff0c\u6570\u636e\u5e93\u4f1a\u81ea\u52a8\u7ed9\u66f4\u5927\u4e00\u7ea7\u7684\u7a7a\u95f4\uff0c\u6bd4\u5982\u6570\u636e\u9875\u6216\u6570\u636e\u8868\u52a0\u4e0a\u610f\u5411\u9501\uff0c\u544a\u8bc9\u5176\u4ed6\u4eba\u8fd9\u4e2a\u6570\u636e\u9875\u6216\u6570\u636e\u8868\u5df2\u7ecf\u6709\u4eba\u4e0a\u8fc7\u6392\u5b83\u9501\u4e86<\/strong>\uff0c\u8fd9\u6837\u5f53\u5176\u4ed6\u4eba\u60f3\u8981\u83b7\u53d6\u6570\u636e\u8868\u6392\u5b83\u9501\u7684\u65f6\u5019\uff0c\u53ea\u9700\u8981\u4e86\u89e3\u662f\u5426\u6709\u4eba\u5df2\u7ecf\u83b7\u53d6\u4e86\u8fd9\u4e2a\u6570\u636e\u8868\u7684\u610f\u5411\u6392\u5b83\u9501\u5373\u53ef\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5982\u679c\u4e8b\u52a1\u60f3\u8981\u83b7\u53d6\u6570\u636e\u8868\u4e2d\u67d0\u4e9b\u8bb0\u5f55\u7684\u5171\u4eab\u9501\uff0c\u5c31\u9700\u8981\u5728\u6570\u636e\u8868\u4e0a<code>\u6dfb\u52a0\u610f\u5411\u5171\u4eab\u9501<\/code><\/li>\n\n\n\n<li>\u5982\u679c\u4e8b\u52a1\u60f3\u8981\u83b7\u53d6\u6570\u636e\u8868\u4e2d\u67d0\u4e9b\u8bb0\u5f55\u7684\u6392\u5b83\u9501\uff0c\u5c31\u9700\u8981\u5728\u6570\u636e\u8868\u4e0a<code>\u6dfb\u52a0\u610f\u5411\u6392\u4ed6\u9501<\/code><\/li>\n<\/ul>\n\n\n\n<p>\u8fd9\u65f6\uff0c\u610f\u5411\u9501\u4f1a\u544a\u8bc9\u5176\u4ed6\u4e8b\u52a1\u5df2\u7ecf\u6709\u4eba\u9501\u5b9a\u4e86\u8868\u4e2d\u7684\u67d0\u4e9b\u8bb0\u5f55\u3002<\/p>\n\n\n\n<p>**\u4e3e\u4f8b:**\u521b\u5efa\u8868teacher\uff0c\u63d2\u51656\u6761\u6570\u636e\uff0c\u4e8b\u52a1\u7684\u9694\u79bb\u7ea7\u522b\u9ed8\u8ba4\u4e3a<code>Repeatable-Read<\/code>\uff0c\u5982\u4e0b\u6240\u793a\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE TABLE `teacher` (\n  `id` int NOT NULL,\n  `name` varchar(255) NOT NULL,\n  PRIMARY KEY (`id`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;\n\nINSERT INTO `teacher` VALUES\n('1', 'zhangsan'),\n('2', 'lisi'),\n('3', 'wangwu'),\n('4', 'zhaoliu'),\n('5', 'songhongkang'),\n('6', 'leifengyang');\n\nSELECT @@transaction_isolation;\n<\/code><\/pre>\n\n\n\n<p>\u5047\u8bbe\u4e8b\u52a1A\u83b7\u53d6\u4e86\u67d0\u4e00\u884c\u7684\u6392\u4ed6\u9501\uff0c\u5e76\u672a\u63d0\u4ea4\uff0c\u8bed\u53e5\u5982\u4e0b\u6240\u793a\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>begin ;\n\nSELECT * FROM teacher WHERE id = 6 FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u4e8b\u52a1B\u60f3\u8981\u83b7\u53d6teacher \u8868\u7684\u8868\u8bfb\u9501\uff0c\u8bed\u53e5\u5982\u4e0b\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>begin;\n\nLOCK TABLES teacher READ;\n<\/code><\/pre>\n\n\n\n<p>\u56e0\u4e3a\u5171\u4eab\u9501\u4e0e\u6392\u4ed6\u9501\u4e92\u65a5\uff0c\u6240\u4ee5\u4e8b\u52a1B\u5728\u8bd5\u56fe\u5bf9teacher\u8868\u52a0\u5171\u4eab\u9501\u7684\u65f6\u5019\uff0c\u5fc5\u987b\u4fdd\u8bc1\u4e24\u4e2a\u6761\u4ef6\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f53\u524d\u6ca1\u6709\u5176\u4ed6\u4e8b\u52a1\u6301\u6709teacher\u8868\u7684\u6392\u4ed6\u9501<\/li>\n\n\n\n<li>\u5f53\u524d\u6ca1\u6709\u5176\u4ed6\u4e8b\u52a1\u6301\u6709teacher\u8868\u4e2d\u4efb\u610f\u4e00\u884c\u7684\u6392\u4ed6\u9501\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u4e3a\u4e86\u68c0\u6d4b\u662f\u5426\u6ee1\u8db3\u7b2c\u4e8c\u4e2a\u6761\u4ef6\uff0c\u4e8b\u52a1B\u5fc5\u987b\u5728\u786e\u4fddteacher\u8868\u4e0d\u5b58\u5728\u4efb\u4f55\u6392\u4ed6\u9501\u7684\u524d\u63d0\u4e0b\uff0c\u53bb\u68c0\u6d4b\u8868\u4e2d\u7684\u6bcf\u4e00\u884c\u662f\u5426\u5b58\u5728\u6392\u4ed6\u9501\u3002\u5f88\u660e\u663e\u8fd9\u662f\u4e00\u4e2a\u6548\u7387\u5f88\u5dee\u7684\u505a\u6cd5\uff0c\u4f46\u662f\u6709\u4e86\u610f\u5411\u9501\u4e4b\u540e\uff0c\u60c5\u51b5\u5c31\u4e0d\u4e00\u6837\u4e86\u3002<\/p>\n\n\n\n<p>\u610f\u5411\u9501\u662f\u600e\u4e48\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u7684\u5462?\u9996\u5148\uff0c\u6211\u4eec\u9700\u8981\u77e5\u9053\u610f\u5411\u9501\u4e4b\u95f4\u7684\u517c\u5bb9\u4e92\u65a5\u6027\uff0c\u5982\u4e0b\u6240\u793a\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><\/th><th>\u610f\u5411\u5171\u4eab\u9501(lS)<\/th><th>\u610f\u5411\u6392\u4ed6\u9501(IX)<\/th><\/tr><\/thead><tbody><tr><td>\u610f\u5411\u5171\u4eab\u9501(IS)<\/td><td>\u517c\u5bb9<\/td><td>\u517c\u5bb9<\/td><\/tr><tr><td>\u610f\u5411\u6392\u4ed6\u9501\uff08IX)<\/td><td>\u517c\u5bb9<\/td><td>\u517c\u5bb9<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u5373\u610f\u5411\u9501\u4e4b\u95f4\u662f\u4e92\u76f8\u517c\u5bb9\u7684\uff0c\u867d\u7136\u610f\u5411\u9501\u548c\u81ea\u5bb6\u5144\u5f1f\u4e92\u76f8\u517c\u5bb9\uff0c\u4f46\u662f\u5b83\u4f1a\u4e0e\u666e\u901a\u7684\u6392\u4ed6\/\u5171\u4eab\u9501\u4e92\u65a5<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><\/th><th>\u610f\u5411\u5171\u4eab\u9501(lS)<\/th><th>\u610f\u5411\u6392\u4ed6\u9501(IX)<\/th><\/tr><\/thead><tbody><tr><td>\u5171\u4eab\u9501(S)\u8868<\/td><td>\u517c\u5bb9<\/td><td>\u4e92\u65a5<\/td><\/tr><tr><td>\u6392\u4ed6\u9501\uff08X)\u8868<\/td><td>\u4e92\u65a5<\/td><td>\u4e92\u65a5<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u6ce8\u610f\u8fd9\u91cc\u7684\u6392\u4ed6\/\u5171\u4eab\u9501\u6307\u7684\u90fd\u662f\u8868\u9501\uff0c\u610f\u5411\u9501\u4e0d\u4f1a\u4e0e\u884c\u7ea7\u7684\u5171\u4eab\/\u6392\u4ed6\u9501\u4e92\u65a5\u3002\u56de\u5230\u521a\u624dteacher\u8868\u7684\u4f8b\u5b50\u3002<\/p>\n\n\n\n<p>\u4e8b\u52a1A\u83b7\u53d6\u4e86\u67d0\u4e00\u884c\u7684\u6392\u4ed6\u9501\uff0c\u5e76\u672a\u63d0\u4ea4:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># \u4e8b\u52a1A\nBEGIN;\nSELECT *FROM teacher WHERE id = 6 FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u6b64\u65f6teacher\u8868\u5b58\u5728\u4e24\u628a\u9501: teacher\u8868\u4e0a\u7684\u610f\u5411\u6392\u4ed6\u9501\u4e0eid\u4e3a6\u7684\u6570\u636e\u884c\u4e0a\u7684\u6392\u4ed6\u9501\u3002\u4e8b\u52a1B\u60f3\u8981\u83b7\u53d6teacher\u8868\u7684\u5171\u4eab\u9501\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># \u4e8b\u52a1B\nBEGIN;\nLOCK TABLES teacher READ;\n<\/code><\/pre>\n\n\n\n<p>\u6b64\u65f6\u4e8b\u52a1B\u68c0\u6d4b\u4e8b\u52a1A\u6301\u6709teacher\u8868\u7684\u610f\u5411\u6392\u4ed6\u9501\uff0c\u5c31\u53ef\u4ee5\u5f97\u77e5\u4e8b\u52a1A\u5fc5\u7136\u6301\u6709\u8be5\u8868\u4e2d\u67d0\u4e9b\u6570\u636e\u884c\u7684\u6392\u4ed6\u9501\uff0c\u90a3\u4e48\u4e8b\u52a1B\u5bf9teacher\u8868\u7684\u52a0\u9501\u8bf7\u6c42\u5c31\u4f1a\u88ab\u6392\u65a5\uff08\u963b\u585e)\uff0c\u800c\u65e0\u9700\u53bb\u68c0\u6d4b\u8868\u4e2d\u7684\u6bcf\u4e00\u884c\u6570\u636e\u662f\u5426\u5b58\u5728\u6392\u4ed6\u9501\u3002<\/p>\n\n\n\n<p><strong>\u610f\u5411\u9501\u7684\u5e76\u53d1\u6027<\/strong><\/p>\n\n\n\n<p>\u610f\u5411\u9501\u4e0d\u4f1a\u4e0e\u884c\u7ea7\u7684\u5171\u4eab\/\u6392\u4ed6\u9501\u4e92\u65a5\uff01\u6b63\u56e0\u4e3a\u5982\u6b64\uff0c\u610f\u5411\u9501\u5e76\u4e0d\u4f1a\u5f71\u54cd\u5230\u591a\u4e2a\u4e8b\u52a1\u5bf9\u4e0d\u540c\u6570\u636e\u884c\u52a0\u6392\u4ed6\u9501\u65f6\u7684\u5e76\u53d1\u6027\u3002\uff08\u4e0d\u7136\u6211\u4eec\u76f4\u63a5\u7528\u666e\u901a\u7684\u8868\u9501\u5c31\u884c\u4e86\uff09<\/p>\n\n\n\n<p>\u6211\u4eec\u6269\u5c55\u4e00\u4e0b\u4e0a\u9762 teacher\u8868\u7684\u4f8b\u5b50\u6765\u6982\u62ec\u4e00\u4e0b\u610f\u5411\u9501\u7684\u4f5c\u7528\uff08\u4e00\u6761\u6570\u636e\u4ece\u88ab\u9501\u5b9a\u5230\u88ab\u91ca\u653e\u7684\u8fc7\u7a0b\u4e2d\uff0c\u53ef\u80fd\u5b58\u5728\u591a\u79cd\u4e0d\u540c\u9501\uff0c\u4f46\u662f\u8fd9\u91cc\u6211\u4eec\u53ea\u7740\u91cd\u8868\u73b0\u610f\u5411\u9501\uff09\u3002<\/p>\n\n\n\n<p>\u4e8b\u52a1 A \u5148\u83b7\u53d6\u4e86\u4e00\u884c\u7684\u6392\u4ed6\u9501\uff0c\u5e76\u672a\u63d0\u4ea4\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>BEGIN;\nSELECT * FROM teacher WHERE id = 6 FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u4e8b\u52a1 A \u83b7\u53d6\u4e86 teacher \u8868\u4e0a\u7684\u610f\u5411\u6392\u4ed6\u9501\uff0c\u4e8b\u52a1 A \u83b7\u53d6\u4e86 id \u4e3a 6 \u7684\u6570\u636e\u884c\u4e0a\u7684\u6392\u4ed6\u9501\u3002\u4e4b\u540e\u4e8b\u52a1 B \u60f3\u8981\u83b7\u53d6 teacher \u8868\u7684\u5171\u4eab\u9501\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>BEGIN;\nLOCK TABLES teacher READ;\n<\/code><\/pre>\n\n\n\n<p>\u4e8b\u52a1 B \u68c0\u6d4b\u5230\u4e8b\u52a1 A \u6301\u6709 teacher \u8868\u7684\u610f\u5411\u6392\u4ed6\u9501\u3002\u4e8b\u52a1 B \u5bf9 teacher \u8868\u7684\u52a0\u9501\u8bf7\u6c42\u88ab\u963b\u585e\uff08\u6392\u65a5\uff09\u3002\u6700\u540e\u4e8b\u52a1 C \u4e5f\u60f3\u83b7\u53d6 teacher \u8868\u4e2d\u67d0\u4e00\u884c\u7684\u6392\u4ed6\u9501\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>BEGIN;\nSELECT * FROM teacher WHERE id = 5 FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u4e8b\u52a1 C \u7533\u8bf7 teacher \u8868\u7684\u610f\u5411\u6392\u4ed6\u9501\u3002\u4e8b\u52a1C \u68c0\u6d4b\u5230\u4e8b\u52a1A \u6301\u6709 teacher \u8868\u7684\u610f\u5411\u6392\u4ed6\u9501\u3002\u56e0\u4e3a\u610f\u5411\u9501\u4e4b\u95f4\u5e76\u4e0d\u4e92\u65a5\uff0c\u6240\u4ee5\u4e8b\u52a1C \u83b7\u53d6\u5230\u4e86 teacher \u8868\u7684\u610f\u5411\u6392\u4ed6\u9501\u3002\u56e0\u4e3aid\u4e3a5\u7684\u6570\u636e\u884c\u4e0a\u4e0d\u5b58\u5728\u4efb\u4f55\u6392\u4ed6\u9501\uff0c\u6700\u7ec8\u4e8b\u52a1C \u6210\u529f\u83b7\u53d6\u5230\u4e86\u8be5\u6570\u636e\u884c\u4e0a\u7684\u6392\u4ed6\u9501\u3002<\/p>\n\n\n\n<p><strong>\u4ece\u4e0a\u9762\u7684\u6848\u4f8b\u53ef\u4ee5\u5f97\u5230\u5982\u4e0b\u7ed3\u8bba\uff1a<\/strong><\/p>\n\n\n\n<p>InnoDB \u652f\u6301<code>\u591a\u7c92\u5ea6\u9501<\/code>\uff0c\u7279\u5b9a\u573a\u666f\u4e0b\uff0c\u884c\u7ea7\u9501\u53ef\u4ee5\u4e0e\u8868\u7ea7\u9501\u5171\u5b58\u3002<\/p>\n\n\n\n<p>\u610f\u5411\u9501\u4e4b\u95f4\u4e92\u4e0d\u6392\u65a5\uff0c\u4f46\u9664\u4e86IS\u4e0eS\u517c\u5bb9\u5916\uff0c<code>\u610f\u5411\u9501\u4f1a\u4e0e \u5171\u4eab\u9501 \/ \u6392\u4ed6\u9501 \u4e92\u65a5<\/code>\u3002<\/p>\n\n\n\n<p>IX\uff0cIS\u662f\u8868\u7ea7\u9501\uff0c\u4e0d\u4f1a\u548c\u884c\u7ea7\u7684X\uff0cS\u9501\u53d1\u751f\u51b2\u7a81\u3002\u53ea\u4f1a\u548c\u8868\u7ea7\u7684X\uff0cS\u53d1\u751f\u51b2\u7a81\u3002<\/p>\n\n\n\n<p>\u610f\u5411\u9501\u5728\u4fdd\u8bc1\u5e76\u53d1\u6027\u7684\u524d\u63d0\u4e0b\uff0c\u5b9e\u73b0\u4e86<code>\u884c\u9501\u548c\u8868\u9501\u5171\u5b58<\/code>\u4e14<code>\u6ee1\u8db3\u4e8b\u52a1\u9694\u79bb\u6027<\/code>\u7684\u8981\u6c42\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"3-\u81ea\u589e\u9501auto-inc\u9501\">\u2462 \u81ea\u589e\u9501\uff08AUTO-INC\u9501\uff09<\/h5>\n\n\n\n<p>\u5728\u4f7f\u7528MySQL\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u4e3a\u8868\u7684\u67d0\u4e2a\u5217\u6dfb\u52a0<code>AUTO_INCREMENT<\/code>\u5c5e\u6027\u3002\u4e3e\u4f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE TABLE `teacher` (\n\t`id` int NOT NULL AUTO_INCREMENT,\n\t`name` varchar( 255 ) NOT NULL,\n\tPRIMARY KEY (`id`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;\n<\/code><\/pre>\n\n\n\n<p>\u7531\u4e8e\u8fd9\u4e2a\u8868\u7684id\u5b57\u6bb5\u58f0\u660e\u4e86AUTO_INCREMENT\uff0c\u610f\u5473\u7740\u5728\u4e66\u5199\u63d2\u5165\u8bed\u53e5\u65f6\u4e0d\u9700\u8981\u4e3a\u5176\u8d4b\u503c<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>INSERT INTO `teacher` (name) VALUES ('zhangsan'), ('lisi');\n<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8fb9\u7684\u63d2\u5165\u8bed\u53e5\u5e76\u6ca1\u6709\u4e3aid\u5217\u663e\u5f0f\u8d4b\u503c\uff0c\u6240\u4ee5\u7cfb\u7edf\u4f1a\u81ea\u52a8\u4e3a\u5b83\u8d4b\u4e0a\u9012\u589e\u7684\u503c\uff0c\u7ed3\u679c\u5982\u4e0b\u6240\u793a\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql> select * from teacher;\n+----+----------+\n| id | name     |\n+----+----------+\n| 1  | zhangsan |\n| 2  | lisi     |\n+----+----------+<\/code><\/pre>\n\n\n\n<p>\u73b0\u5728\u6211\u4eec\u770b\u5230\u7684\u4e0a\u9762\u63d2\u5165\u6570\u636e\u53ea\u662f\u4e00\u79cd\u7b80\u5355\u7684\u63d2\u5165\u6a21\u5f0f\uff0c\u6240\u6709\u63d2\u5165\u6570\u636e\u7684\u65b9\u5f0f\u603b\u5171\u5206\u4e3a\u4e09\u7c7b\uff0c\u5206\u522b\u662f\u201c<code>Simple inserts<\/code>\u201d\uff0c\u201c<code>Bulk inserts<\/code>\u201d\u548c\u201c<code>Mixed-mode inserts<\/code>\u201d\u3002<\/p>\n\n\n\n<p><strong>\u201cSimple inserts\u201d\uff08\u7b80\u5355\u63d2\u5165\uff09<\/strong><\/p>\n\n\n\n<p>\u53ef\u4ee5<code>\u9884\u5148\u786e\u5b9a\u8981\u63d2\u5165\u7684\u884c\u6570<\/code>\uff08\u5f53\u8bed\u53e5\u88ab\u521d\u59cb\u5904\u7406\u65f6\uff09\u7684\u8bed\u53e5\u3002\u5305\u62ec\u6ca1\u6709\u5d4c\u5957\u5b50\u67e5\u8be2\u7684\u5355\u884c\u548c\u591a\u884c<code>INSERT...VALUES()<\/code>\u548c<code>REPLACE<\/code>\u8bed\u53e5\u3002\u4e0d\u5305\u62ec<code>INSERT...ON DUPLICATE KEY UPDATE<\/code>\u8bed\u53e5\u3002<\/p>\n\n\n\n<p><strong>\u201cBulk inserts\u201d \uff08\u6279\u91cf\u63d2\u5165\uff09<\/strong><\/p>\n\n\n\n<p><code>\u4e8b\u5148\u4e0d\u77e5\u9053\u8981\u63d2\u5165\u7684\u884c\u6570<\/code>\uff08\u548c\u6240\u9700\u81ea\u52a8\u9012\u589e\u503c\u7684\u6570\u91cf\uff09\u7684\u8bed\u53e5\u3002\u6bd4\u5982<code>INSERT ... SELECT<\/code>\uff0c<code>REPLACE ... SELECT<\/code>\u548c<code>LOAD DATA<\/code>\u8bed\u53e5\uff0c\u4f46\u4e0d\u5305\u62ec\u7eafINSERT\u3002 InnoDB\u5728\u6bcf\u5904\u7406\u4e00\u884c\uff0c\u4e3aAUTO_INCREMENT\u5217\u5206\u914d\u4e00\u4e2a\u65b0\u503c\u3002<\/p>\n\n\n\n<p><strong>\u201cMixed-mode inserts\u201d\uff08\u6df7\u5408\u6a21\u5f0f\u63d2\u5165\uff09<\/strong><\/p>\n\n\n\n<p>\u8fd9\u4e9b\u662f\u201cSimple inserts\u201d\u8bed\u53e5\u4f46\u662f\u6307\u5b9a\u90e8\u5206\u65b0\u884c\u7684\u81ea\u52a8\u9012\u589e\u503c\u3002\u4f8b\u5982<code>INSERT INTO teacher (id,name) VALUES (1,'a'), (NULL,'b'), (5,'c'), (NULL,'d');<\/code>\u53ea\u662f\u6307\u5b9a\u4e86\u90e8\u5206id\u7684\u503c\u3002\u53e6\u4e00\u79cd\u7c7b\u578b\u7684\u201c\u6df7\u5408\u6a21\u5f0f\u63d2\u5165\u201d\u662f<code>INSERT ... ON DUPLICATE KEY UPDATE<\/code>\u3002<\/p>\n\n\n\n<p>\u5bf9\u4e8e\u4e0a\u9762\u6570\u636e\u63d2\u5165\u7684\u6848\u4f8b\uff0cMySQL\u91c7\u7528\u4e86<code>\u81ea\u589e\u9501<\/code>\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0\uff0c<strong>AUTO-INT\u9501\u662f\u5f53\u5411\u4f7f\u7528\u542b\u6709AUTO_INCREMENT\u5217\u7684\u8868\u4e2d\u63d2\u5165\u6570\u636e\u65f6\u9700\u8981\u83b7\u53d6\u7684\u4e00\u79cd\u7279\u6b8a\u7684\u8868\u7ea7\u9501<\/strong>\uff0c\u5728\u6267\u884c\u63d2\u5165\u8bed\u53e5\u65f6\u5c31\u5728\u8868\u7ea7\u522b\u52a0\u4e00\u4e2aAUTO-INT\u9501\uff0c\u7136\u540e\u4e3a\u6bcf\u6761\u5f85\u63d2\u5165\u8bb0\u5f55\u7684AUTO_INCREMENT\u4fee\u9970\u7684\u5217\u5206\u914d\u9012\u589e\u7684\u503c\uff0c\u5728\u8be5\u8bed\u53e5\u6267\u884c\u7ed3\u675f\u540e\uff0c\u518d\u628aAUTO-INT\u9501\u91ca\u653e\u6389\u3002<strong>\u4e00\u4e2a\u4e8b\u52a1\u5728\u6301\u6709AUTO-INC\u9501\u7684\u8fc7\u7a0b\u4e2d\uff0c\u5176\u4ed6\u4e8b\u52a1\u7684\u63d2\u5165\u8bed\u53e5\u90fd\u8981\u88ab\u963b\u585e<\/strong>\uff0c\u53ef\u4ee5\u4fdd\u8bc1\u4e00\u4e2a\u8bed\u53e5\u4e2d\u5206\u914d\u7684\u9012\u589e\u503c\u662f\u8fde\u7eed\u7684\u3002\u4e5f\u6b63\u56e0\u4e3a\u6b64\uff0c\u5176\u5e76\u53d1\u6027\u663e\u7136\u5e76\u4e0d\u9ad8\uff0c<strong>\u5f53\u6211\u4eec\u5411\u4e00\u4e2a\u6709AUTO_INCREMENT\u5173\u952e\u5b57\u7684\u4e3b\u952e\u63d2\u5165\u503c\u7684\u65f6\u5019\uff0c\u6bcf\u6761\u8bed\u53e5\u90fd\u8981\u5bf9\u8fd9\u4e2a\u8868\u9501\u8fdb\u884c\u7ade\u4e89<\/strong>\uff0c\u8fd9\u6837\u7684\u5e76\u53d1\u6f5c\u529b\u5176\u5b9e\u662f\u5f88\u4f4e\u4e0b\u7684\uff0c\u6240\u4ee5innodb\u901a\u8fc7<code>innodb_autoinc_lock_mode<\/code>\u7684\u4e0d\u540c\u53d6\u503c\u6765\u63d0\u4f9b\u4e0d\u540c\u7684\u9501\u5b9a\u673a\u5236\uff0c\u6765\u663e\u8457\u63d0\u9ad8SQL\u8bed\u53e5\u7684\u53ef\u4f38\u7f29\u6027\u548c\u6027\u80fd\u3002<\/p>\n\n\n\n<p>innodb_autoinc_lock_mode\u6709\u4e09\u79cd\u53d6\u503c\uff0c\u5206\u522b\u5bf9\u5e94\u4e0e\u4e0d\u540c\u9501\u5b9a\u6a21\u5f0f\uff1a<\/p>\n\n\n\n<p><code>\uff081\uff09innodb_autoinc_lock_mode = 0(\u201c\u4f20\u7edf\u201d\u9501\u5b9a\u6a21\u5f0f)<\/code><\/p>\n\n\n\n<p>\u5728\u6b64\u9501\u5b9a\u6a21\u5f0f\u4e0b\uff0c\u6240\u6709\u7c7b\u578b\u7684insert\u8bed\u53e5\u90fd\u4f1a\u83b7\u5f97\u4e00\u4e2a\u7279\u6b8a\u7684\u8868\u7ea7AUTO-INC\u9501\uff0c\u7528\u4e8e\u63d2\u5165\u5177\u6709AUTO_INCREMENT\u5217\u7684\u8868\u3002\u8fd9\u79cd\u6a21\u5f0f\u5176\u5b9e\u5c31\u5982\u6211\u4eec\u4e0a\u9762\u7684\u4f8b\u5b50\uff0c\u5373\u6bcf\u5f53\u6267\u884cinsert\u7684\u65f6\u5019\uff0c\u90fd\u4f1a\u5f97\u5230\u4e00\u4e2a\u8868\u7ea7\u9501(AUTO-INC\u9501)\uff0c\u4f7f\u5f97\u8bed\u53e5\u4e2d\u751f\u6210\u7684auto_increment\u4e3a\u987a\u5e8f\uff0c\u4e14\u5728binlog\u4e2d\u91cd\u653e\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u4fdd\u8bc1master\u4e0eslave\u4e2d\u6570\u636e\u7684auto_increment\u662f\u76f8\u540c\u7684\u3002\u56e0\u4e3a\u662f\u8868\u7ea7\u9501\uff0c\u5f53\u5728\u540c\u4e00\u65f6\u95f4\u591a\u4e2a\u4e8b\u52a1\u4e2d\u6267\u884cinsert\u7684\u65f6\u5019\uff0c\u5bf9\u4e8eAUTO-INC\u9501\u7684\u4e89\u593a\u4f1a<code>\u9650\u5236\u5e76\u53d1<\/code>\u80fd\u529b\u3002<\/p>\n\n\n\n<p><code>\uff082\uff09innodb_autoinc_lock_mode = 1(\u201c\u8fde\u7eed\u201d\u9501\u5b9a\u6a21\u5f0f)<\/code><\/p>\n\n\n\n<p>\u5728 MySQL 8.0 \u4e4b\u524d\uff0c\u8fde\u7eed\u9501\u5b9a\u6a21\u5f0f\u662f<code>\u9ed8\u8ba4<\/code>\u7684\u3002<\/p>\n\n\n\n<p>\u5728\u8fd9\u4e2a\u6a21\u5f0f\u4e0b\uff0c\u201cbulk inserts\u201d\u4ecd\u7136\u4f7f\u7528AUTO-INC\u8868\u7ea7\u9501\uff0c\u5e76\u4fdd\u6301\u5230\u8bed\u53e5\u7ed3\u675f\u3002\u8fd9\u9002\u7528\u4e8e\u6240\u6709INSERT ... SELECT\uff0cREPLACE ... SELECT\u548cLOAD DATA\u8bed\u53e5\u3002\u540c\u4e00\u65f6\u523b\u53ea\u6709\u4e00\u4e2a\u8bed\u53e5\u53ef\u4ee5\u6301\u6709AUTO-INC\u9501\u3002<\/p>\n\n\n\n<p>\u5bf9\u4e8e\u201cSimple inserts\u201d\uff08\u8981\u63d2\u5165\u7684\u884c\u6570\u4e8b\u5148\u5df2\u77e5\uff09\uff0c\u5219\u901a\u8fc7\u5728<code>mutex\uff08\u8f7b\u91cf\u9501\uff09<\/code>\u7684\u63a7\u5236\u4e0b\u83b7\u5f97\u6240\u9700\u6570\u91cf\u7684\u81ea\u52a8\u9012\u589e\u503c\u6765\u907f\u514d\u8868\u7ea7AUTO-INC\u9501\uff0c \u5b83\u53ea\u5728\u5206\u914d\u8fc7\u7a0b\u7684\u6301\u7eed\u65f6\u95f4\u5185\u4fdd\u6301\uff0c\u800c\u4e0d\u662f\u76f4\u5230\u8bed\u53e5\u5b8c\u6210\u3002\u4e0d\u4f7f\u7528\u8868\u7ea7AUTO-INC\u9501\uff0c\u9664\u975eAUTO-INC\u9501\u7531\u53e6\u4e00\u4e2a\u4e8b\u52a1\u4fdd\u6301\u3002\u5982\u679c\u53e6\u4e00\u4e2a\u4e8b\u52a1\u4fdd\u6301AUTO-INC\u9501\uff0c\u5219\u201cSimple inserts\u201d\u7b49\u5f85AUTO-INC\u9501\uff0c\u5982\u540c\u5b83\u662f\u4e00\u4e2a\u201cbulk inserts\u201d\u3002<\/p>\n\n\n\n<p><code>\uff083\uff09innodb_autoinc_lock_mode = 2(\u201c\u4ea4\u9519\u201d\u9501\u5b9a\u6a21\u5f0f)<\/code><\/p>\n\n\n\n<p>\u4ece MySQL 8.0 \u5f00\u59cb\uff0c\u4ea4\u9519\u9501\u6a21\u5f0f\u662f<code>\u9ed8\u8ba4<\/code>\u8bbe\u7f6e\u3002<\/p>\n\n\n\n<p>\u5728\u8fd9\u79cd\u9501\u5b9a\u6a21\u5f0f\u4e0b\uff0c\u6240\u6709\u7c7bINSERT\u8bed\u53e5\u90fd\u4e0d\u4f1a\u4f7f\u7528\u8868\u7ea7AUTO-INC\u9501\uff0c\u5e76\u4e14\u53ef\u4ee5\u540c\u65f6\u6267\u884c\u591a\u4e2a\u8bed\u53e5\u3002\u8fd9\u662f\u6700\u5feb\u548c\u6700\u53ef\u62d3\u5c55\u7684\u9501\u5b9a\u6a21\u5f0f\uff0c\u4f46\u662f\u5f53\u4f7f\u7528\u57fa\u4e8e\u8bed\u53e5\u7684\u590d\u5236\u6216\u6062\u590d\u65b9\u6848\u65f6\uff0c<strong>\u4ece\u4e8c\u8fdb\u5236\u65e5\u5fd7\u91cd\u64adSQL\u8bed\u53e5\u65f6\uff0c\u8fd9\u662f\u4e0d\u5b89\u5168\u7684\u3002<\/strong><\/p>\n\n\n\n<p>\u5728\u6b64\u9501\u5b9a\u6a21\u5f0f\u4e0b\uff0c\u81ea\u52a8\u9012\u589e\u503c<code>\u4fdd\u8bc1<\/code>\u5728\u6240\u6709\u5e76\u53d1\u6267\u884c\u7684\u6240\u6709\u7c7b\u578b\u7684insert\u8bed\u53e5\u4e2d\u662f<code>\u552f\u4e00<\/code>\u4e14<code>\u5355\u8c03\u9012\u589e<\/code>\u7684\u3002\u4f46\u662f\uff0c\u7531\u4e8e\u591a\u4e2a\u8bed\u53e5\u53ef\u4ee5\u540c\u65f6\u751f\u6210\u6570\u5b57\uff08\u5373\uff0c\u8de8\u8bed\u53e5\u4ea4\u53c9\u7f16\u53f7\uff09\uff0c<strong>\u4e3a\u4efb\u4f55\u7ed9\u5b9a\u8bed\u53e5\u63d2\u5165\u7684\u884c\u751f\u6210\u7684\u503c\u53ef\u80fd\u4e0d\u662f\u8fde\u7eed\u7684\u3002<\/strong><\/p>\n\n\n\n<p>\u5982\u679c\u6267\u884c\u7684\u8bed\u53e5\u662f\u201csimple inserts\u201d\uff0c\u5176\u4e2d\u8981\u63d2\u5165\u7684\u884c\u6570\u5df2\u63d0\u524d\u77e5\u9053\uff0c\u9664\u4e86\u201cMixed-mode inserts\"\u4e4b\u5916\uff0c\u4e3a\u5355\u4e2a\u8bed\u53e5\u751f\u6210\u7684\u6570\u5b57\u4e0d\u4f1a\u6709\u95f4\u9699\u3002\u7136\u800c\uff0c\u5f53\u6267\u884c\u201cbulk inserts\"\u65f6,\u5728\u7531\u4efb\u4f55\u7ed9\u5b9a\u8bed\u53e5\u5206\u914d\u7684\u81ea\u52a8\u9012\u589e\u503c\u4e2d\u53ef\u80fd\u5b58\u5728\u95f4\u9699\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"4-\u5143\u6570\u636e\u9501mdl\u9501\">\u2463 \u5143\u6570\u636e\u9501\uff08MDL\u9501\uff09<\/h5>\n\n\n\n<p>MySQL5.5\u5f15\u5165\u4e86meta data lock\uff0c\u7b80\u79f0MDL\u9501\uff0c\u5c5e\u4e8e\u8868\u9501\u8303\u7574\u3002MDL \u7684\u4f5c\u7528\u662f\uff0c\u4fdd\u8bc1\u8bfb\u5199\u7684\u6b63\u786e\u6027\u3002\u6bd4\u5982\uff0c\u5982\u679c\u4e00\u4e2a\u67e5\u8be2\u6b63\u5728\u904d\u5386\u4e00\u4e2a\u8868\u4e2d\u7684\u6570\u636e\uff0c\u800c\u6267\u884c\u671f\u95f4\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5bf9\u8fd9\u4e2a<code>\u8868\u7ed3\u6784\u505a\u53d8\u66f4<\/code>\uff0c\u589e\u52a0\u4e86\u4e00\u5217\uff0c\u90a3\u4e48\u67e5\u8be2\u7ebf\u7a0b\u62ff\u5230\u7684\u7ed3\u679c\u8ddf\u8868\u7ed3\u6784\u5bf9\u4e0d\u4e0a\uff0c\u80af\u5b9a\u662f\u4e0d\u884c\u7684\u3002<\/p>\n\n\n\n<p>\u56e0\u6b64\uff0c<strong>\u5f53\u5bf9\u4e00\u4e2a\u8868\u505a\u589e\u5220\u6539\u67e5\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u52a0MDL\u8bfb\u9501\uff1b\u5f53\u8981\u5bf9\u8868\u505a\u7ed3\u6784\u53d8\u66f4\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u52a0MDL\u5199\u9501\u3002<\/strong><\/p>\n\n\n\n<p>\u8bfb\u9501\u4e4b\u95f4\u4e0d\u4e92\u65a5\uff0c\u56e0\u6b64\u4f60\u53ef\u4ee5\u6709\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u5bf9\u4e00\u5f20\u8868\u589e\u5220\u6539\u67e5\u3002\u8bfb\u5199\u9501\u4e4b\u95f4\u3001\u5199\u9501\u4e4b\u95f4\u662f\u4e92\u65a5\u7684\uff0c\u7528\u6765\u4fdd\u8bc1\u53d8\u66f4\u8868\u7ed3\u6784\u64cd\u4f5c\u7684\u5b89\u5168\u6027\uff0c\u89e3\u51b3\u4e86DML\u548cDDL\u64cd\u4f5c\u4e4b\u95f4\u7684\u4e00\u81f4\u6027\u95ee\u9898\u3002<code>\u4e0d\u9700\u8981\u663e\u5f0f\u4f7f\u7528<\/code>\uff0c\u5728\u8bbf\u95ee\u4e00\u4e2a\u8868\u7684\u65f6\u5019\u4f1a\u88ab\u81ea\u52a8\u52a0\u4e0a\u3002<\/p>\n\n\n\n<p><strong>\u4e3e\u4f8b:\u5143\u6570\u636e\u9501\u7684\u4f7f\u7528\u573a\u666f\u6a21\u62df<\/strong><\/p>\n\n\n\n<p>\u4f1a\u8bddA:\u4ece\u8868\u4e2d\u67e5\u8be2\u6570\u636e<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql&gt; begin;\nQuery 0K,0 rows affected (0.00 sec)\n# \u9ed8\u8ba4\u52a0\u4e86MDL\u8bfb\u9501\nmysql&gt; select count(1) from teacher;\n<\/code><\/pre>\n\n\n\n<p>\u4f1a\u8bddB\uff1a\u4fee\u6539\u8868\u7ed3\u6784\uff0c\u589e\u52a0\u65b0\u5217<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>begin;\n\n# \u8fd9\u4e2a\u65f6\u5019\u5c31\u4f1a\u963b\u585e\u5728\u8fd9\u91cc\uff0c\u6709\u5176\u4ed6\u4e8b\u52a1\u5728\u8bfb\u6570\u636e\u3002\n# \u4fee\u6539\u8868\u7ed3\u6784\u9700\u8981\u52a0MDL\u5199\u9501\nalter table teacher add age int not null;\n<\/code><\/pre>\n\n\n\n<p>\u4f1a\u8bddC\uff1a\u67e5\u770b\u5f53\u524dMySQL\u7684\u8fdb\u7a0b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># \u67e5\u770b\u7ebf\u7a0b\uff0c\u4ee5\u53ca\u7ebf\u7a0b\u7b49\u5f85\u5177\u4f53\u9501\u7684\u72b6\u6001\nSHOW PROCESSLIST;\n<\/code><\/pre>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"181\" width=\"1157\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/11ebe938a93640039e06ec4f46c8f10e.png\" alt=\"\"><\/p>\n\n\n\n<p>\u901a\u8fc7\u4f1a\u8bddC\u53ef\u4ee5\u770b\u51fa\u4f1a\u8bddB\u88ab\u963b\u585e\uff0c\u8fd9\u662f\u7531\u4e8e\u4f1a\u8bddA\u62ff\u5230\u4e86teacher\u8868\u7684\u5143\u6570\u636e\u8bfb\u9501\uff0c\u4f1a\u8bddB\u60f3\u7533\u8bf7teacher\u8868\u7684\u5143\u6570\u636e\u5199\u9501\uff0c\u7531\u4e8e\u8bfb\u5199\u9501\u4e92\u65a5\uff0c\u4f1a\u8bddB\u9700\u8981\u7b49\u5f85\u4f1a\u8bddA\u91ca\u653e\u5143\u6570\u636e\u9501\u624d\u80fd\u6267\u884c\u3002<\/p>\n\n\n\n<p><strong>\u5143\u6570\u636e\u9501\u53ef\u80fd\u5e26\u6765\u7684\u95ee\u9898<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Session A<\/th><th>Session B<\/th><th>Session C<\/th><\/tr><\/thead><tbody><tr><td>begin;select * from teacher;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>alter table teacher add age int;<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>select * from teacher;<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u6211\u4eec\u53ef\u4ee5\u770b\u5230session A \u4f1a\u5bf9\u8868teacher\u52a0\u4e00\u4e2aMDL\u8bfb\u9501\uff0c\u4e4b\u540e session B \u8981\u52a0 MDL\u5199\u9501 \u4f1a\u88abblocked\uff0c\u56e0\u4e3a session A \u7684MDL\u8bfb\u9501\u8fd8\u6ca1\u6709\u91ca\u653e\uff0c\u800csession C\u8981\u5728\u8868teacher\u4e0a\u65b0\u7533\u8bf7 MDL\u8bfb\u9501 \u7684\u8bf7\u6c42\u4e5f\u4f1a\u88ab session B \u963b\u585e\u3002\u524d\u9762\u6211\u4eec\u8bf4\u4e86\uff0c\u6240\u6709\u5bf9\u8868\u7684\u589e\u5220\u6539\u67e5\u64cd\u4f5c\u90fd\u9700\u8981\u5148\u7533\u8bf7 MDL \u8bfb\u9501\uff0c\u5c31\u90fd\u88ab\u963b\u585e\uff0c\u7b49\u4e8e\u8fd9\u4e2a\u8868\u73b0\u5728\u5b8c\u5168\u4e0d\u53ef\u8bfb\u5199\u4e86\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"322-innodb\u4e2d\u7684\u884c\u9501\">3.2.2 InnoDB\u4e2d\u7684\u884c\u9501<\/h4>\n\n\n\n<p>\u884c\u9501\uff08Row Lock\uff09\u4e5f\u79f0\u4e3a\u8bb0\u5f55\u9501\uff0c\u987e\u540d\u601d\u4e49\uff0c\u5c31\u662f\u9501\u4f4f\u67d0\u4e00\u884c\uff08\u67d0\u6761\u8bb0\u5f55row\uff09\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0cMySQL\u670d\u52a1\u5668\u5c42\u5e76\u6ca1\u6709\u5b9e\u73b0\u884c\u9501\u673a\u5236\uff0c<strong>\u884c\u7ea7\u9501\u53ea\u5728\u5b58\u50a8\u5f15\u64ce\u5c42\u5b9e\u73b0\u3002<\/strong><\/p>\n\n\n\n<p>**\u4f18\u70b9\uff1a**\u9501\u5b9a\u529b\u5ea6\u5c0f\uff0c\u53d1\u751f<code>\u9501\u51b2\u7a81\u6982\u7387\u4f4e<\/code>\uff0c\u53ef\u4ee5\u5b9e\u73b0\u7684<code>\u5e76\u53d1\u5ea6\u9ad8<\/code><\/p>\n\n\n\n<p>**\u7f3a\u70b9\uff1a**\u5bf9\u4e8e<code>\u9501\u7684\u5f00\u9500\u6bd4\u8f83\u5927<\/code>\uff0c\u52a0\u9501\u4f1a\u6bd4\u8f83\u6162\uff0c\u5bb9\u6613\u51fa\u73b0<code>\u6b7b\u9501<\/code>\u60c5\u51b5<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>InnoDB\u4e0eMyISAM\u7684\u6700\u5927\u4e0d\u540c\u6709\u4e24\u70b9\uff1a\u4e00\u662f\u652f\u6301\u4e8b\u52a1\uff1b\u4e8c\u662f\u91c7\u7528\u4e86\u884c\u7ea7\u9501\u3002<\/p>\n<\/blockquote>\n\n\n\n<p>\u521b\u5efa\u5b66\u751f\u8868student\uff0c\u5e76\u63d2\u5165\u6570\u636e\uff0c\u7528\u4e8e\u8bb2\u89e3\u4ee5\u4e0b\u884c\u9501<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE TABLE student (\n\tid INT,name VARCHAR(20) ,\n    class varchar(10) ,\n    PRIMARY KEY (id)\n) Engine=InnoDB CHARSET=utf8;\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>INSERT INTO student VALUES \n(1,'\u5f20\u4e09','\u4e00\u73ed'),\n(3,'\u674e\u56db','\u4e00\u73ed') ,\n(8,'\u738b\u4e94','\u4e8c\u73ed') ,\n(15,'\u8d75\u516d','\u4e8c\u73ed') ,\n(20,'\u94b1\u4e03','\u4e09\u73ed');\n<\/code><\/pre>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"1-\u8bb0\u5f55\u9501record-locks\">\u2460 \u8bb0\u5f55\u9501\uff08Record Locks\uff09<\/h5>\n\n\n\n<p>\u8bb0\u5f55\u9501\u7528\u4e8e\u9501\u5b9a\u67d0\u4e00\u6761\u8bb0\u5f55\uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a<code>LOCK_REC_NOT_GAP<\/code>\u3002<\/p>\n\n\n\n<p>\u8bb0\u5f55\u9501\u4ec5\u9501\u5b9a\u4e00\u6761\u8bb0\u5f55\uff0c\u5bf9\u5176\u4ed6\u8bb0\u5f55\u6ca1\u6709\u5f71\u54cd\u3002<\/p>\n\n\n\n<p>\u8bb0\u5f55\u9501\u662f\u6709S\u9501\u548cX\u9501\u4e4b\u5206\u7684\uff0c\u79f0\u4e4b\u4e3a<code>S\u578b\u8bb0\u5f55\u9501<\/code>\u548c<code>X\u578b\u8bb0\u5f55\u9501<\/code>\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f53\u4e00\u4e2a\u4e8b\u52a1\u83b7\u53d6\u4e86\u4e00\u6761\u8bb0\u5f55\u7684S\u578b\u8bb0\u5f55\u9501\u540e\uff0c\u5176\u4ed6\u4e8b\u52a1\u4e5f\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6\u8be5\u8bb0\u5f55\u7684S\u578b\u8bb0\u5f55\u9501\uff0c\u4f46\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6X\u578b\u8bb0\u5f55\u9501\uff1b<\/li>\n\n\n\n<li>\u5f53\u4e00\u4e2a\u4e8b\u52a1\u83b7\u53d6\u4e86\u4e00\u6761\u8bb0\u5f55\u7684X\u578b\u8bb0\u5f55\u9501\u540e\uff0c\u5176\u4ed6\u4e8b\u52a1\u65e2\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6\u8be5\u8bb0\u5f55\u7684S\u578b\u8bb0\u5f55\u9501\uff0c\u4e5f\u4e0d\u53ef\u4ee5\u7ee7\u7eed\u83b7\u53d6X\u578b\u8bb0\u5f55\u9501\u3002<\/li>\n<\/ul>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"596\" width=\"1154\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/81617f7087914f1dbbfdb7969801678f.png\" alt=\"\"><\/p>\n\n\n\n<p>\u8bbe\u7f6e\u975e\u81ea\u52a8\u63d0\u4ea4\u4e8b\u52a1\uff1b\u5728\u4f1a\u8bdd1\u4e2d\u66f4\u65b0id=1\u7684\u8bb0\u5f55\u4f46\u4e0d\u63d0\u4ea4\uff1b<\/p>\n\n\n\n<p>\u5728\u4f1a\u8bdd2\u4e2d\u66f4\u65b0id=3\u7684\u8bb0\u5f55\uff0c\u6ca1\u6709\u88ab\u963b\u585e\u3002<\/p>\n\n\n\n<p>\u5728\u4f1a\u8bdd2\u4e2d\u66f4\u65b0id=1\u7684\u8bb0\u5f55\uff0c\u88ab\u963b\u585e\uff0c\u8d85\u65f6\u540e\u518d\u6b21\u53d1\u51fa\u66f4\u65b0\u8bf7\u6c42\uff0c\u6b64\u65f6\u4f1a\u8bdd1\u63d0\u4ea4\u4e8b\u52a1\uff0c\u4f1a\u53d1\u73b0\u4f1a\u8bdd2\u4e2d\u7684\u8bed\u53e5\u89e3\u9664\u4e86\u963b\u585e\u3002\u8fd9\u8bf4\u660e\u53ea\u6709id=1\u7684\u8bb0\u5f55\u88ab\u9501\u5b9a\u4e86\uff0c\u4e5f\u5c31\u662f\u53ea\u9501\u5b9a\u4e86\u4e00\u6761\u8bb0\u5f55\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"2-\u95f4\u9699\u9501gap-locks\">\u2461 \u95f4\u9699\u9501\uff08Gap Locks\uff09<\/h5>\n\n\n\n<p><code>MySQL<\/code>\u5728<code>REPEATABLE READ<\/code>\u9694\u79bb\u7ea7\u522b\u4e0b\u662f\u53ef\u4ee5\u89e3\u51b3\u5e7b\u8bfb\u95ee\u9898\u7684\uff0c\u89e3\u51b3\u65b9\u6848\u6709\u4e24\u79cd\uff0c\u53ef\u4ee5\u4f7f\u7528<code>MVCC<\/code>\u65b9\u6848\u89e3\u51b3\uff0c\u4e5f\u53ef\u4ee5\u91c7\u7528<code>\u52a0\u9501<\/code>\u65b9\u6848\u89e3\u51b3\u3002\u4f46\u662f\u5728\u4f7f\u7528\u52a0\u9501\u65b9\u6848\u89e3\u51b3\u65f6\u6709\u4e2a\u5927\u95ee\u9898\uff0c\u5c31\u662f\u4e8b\u52a1\u5728\u7b2c\u4e00\u6b21\u6267\u884c\u8bfb\u53d6\u64cd\u4f5c\u65f6\uff0c\u90a3\u4e9b\u5e7b\u5f71\u8bb0\u5f55\u5c1a\u4e0d\u5b58\u5728\uff0c\u6211\u4eec\u65e0\u6cd5\u7ed9\u8fd9\u4e9b<code>\u5e7b\u5f71\u8bb0\u5f55<\/code>\u52a0\u4e0a<code>\u8bb0\u5f55\u9501<\/code>\u3002InnoDB\u63d0\u51fa\u4e86\u4e00\u79cd\u79f0\u4e4b\u4e3a<code>Gap Locks<\/code>\u7684\u9501\uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a<code>LOCK_GAP<\/code>\uff0c\u6211\u4eec\u53ef\u4ee5\u7b80\u79f0\u4e3a<code>gap\u9501<\/code>\u3002<\/p>\n\n\n\n<p>**\u95f4\u9699\u9501\u7528\u4e8e\u9501\u5b9a\u7d22\u5f15\u8bb0\u5f55\u4e4b\u95f4\u7684\u95f4\u9699\uff0c**\u5176\u4e3b\u8981\u76ee\u7684\u662f\u4e3a\u4e86\u9632\u6b62\u5728\u5f53\u524d\u4e8b\u52a1\u6267\u884c\u671f\u95f4\u6709\u5176\u4ed6\u4e8b\u52a1\u5728\u8fd9\u4e9b\u95f4\u9699\u4e2d\u63d2\u5165\u65b0\u7684\u8bb0\u5f55\uff0c\u4ece\u800c\u7ef4\u6301\u4e8b\u52a1\u7684\u4e00\u81f4\u6027\u3002<\/p>\n\n\n\n<p><strong>\u4e3e\u4f8b<\/strong><\/p>\n\n\n\n<p>\u8868student\u4e2d\u5b58\u5728&nbsp;<code>(Infimum,1]<\/code>\u3001<code>(1,3]<\/code>\u3001<code>(3,8]<\/code>\u3001<code>(8,15]<\/code>\u3001<code>(15,20]&nbsp;<\/code>\u548c<code>(20,Supremum)<\/code>\u7b49\u95f4\u9699\uff0c\u5176\u4e2d, Infimum \u8868\u793a\u8be5\u9875\u9762\u4e2d\u7684\u6700\u5c0f\u8bb0\u5f55\uff0cSupremum \u8868\u793a\u8be5\u9875\u9762\u4e2d\u7684\u6700\u5927\u8bb0\u5f55\u3002<\/p>\n\n\n\n<p>\u7ed9 id=8 \u7684\u8bb0\u5f55\u52a0\u95f4\u9699\u9501\u7684\u793a\u610f\u56fe\u5982\u56fe\u6240\u793a\uff0c\u9501\u5b9a\u533a\u95f4\u662f<code>(3,8)<\/code>\uff0c\u6ce8\u610f\u662f\u5f00\u533a\u95f4\u3002<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"397\" width=\"1146\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/eb7e0fc1f6dc45cb8bc923d77c02a382.png\" alt=\"\"><\/p>\n\n\n\n<p>\u5f53\u53e6\u5916\u4e00\u4e2a\u4e8b\u52a1\u518d\u60f3\u63d2\u5165\u4e00\u6761id\u503c\u4e3a4\u7684\u65b0\u8bb0\u5f55\uff0c\u5b83\u5b9a\u4f4d\u5230\u8be5\u6761\u65b0\u8bb0\u5f55\u7684\u4e0b\u4e00\u6761\u8bb0\u5f55\u7684id\u503c\u4e3a8\uff0c\u800c\u8fd9\u6761\u8bb0\u5f55\u4e0a\u53c8\u6709\u4e00\u4e2agap\u9501\uff0c\u6240\u4ee5\u5c31\u4f1a\u963b\u585e\u63d2\u5165\u64cd\u4f5c\uff0c\u76f4\u5230\u62e5\u6709\u8fd9\u4e2agap\u9501\u7684\u4e8b\u52a1\u63d0\u4ea4\u4e4b\u540e\uff0cid\u5217\u7684\u503c\u5728\u533a\u95f4(3,8)\u4e2d\u7684\u65b0\u8bb0\u5f55\u624d\u53ef\u4ee5\u88ab\u63d2\u5165\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>BEGIN;\nSELECT * FROM student WHERE id=5 LOCK IN SHARE MODE;\nSELECT * FROM performance_schema.data_locks\\G\n*************************** row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109607664:39:4:4:139647036503760\nENGINE_TRANSACTION_ID: 421122086318320\n            THREAD_ID: 89\n             EVENT_ID: 18\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 139647036503760\n            LOCK_TYPE: RECORD\n            LOCK_MODE: S,GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 8\n<\/code><\/pre>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>5 \u8fd9\u6761\u8bb0\u5f55\u4e0d\u5b58\u5728\uff0c\u6240\u4ee5\u662f\u95f4\u9699\u9501\uff0c\u9501\u7684\u662f\uff083,8\uff09\u8fd9\u4e2a\u533a\u95f4\u3002<\/p>\n\n\n\n<p>\u5982\u679c 5 \u8fd9\u6761\u8bb0\u5f55\u5b58\u5728\uff0c\u5219\u4e0d\u662f\u95f4\u9699\u9501\uff0c\u800c\u662f\u8bb0\u5f55\u9501\u3002&nbsp;<code>LOCK_DATA<\/code>&nbsp;\u663e\u793a\u7684\u662f\u8be5\u95f4\u9699\u7684<strong>\u53f3\u8fb9\u754c<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p>**gap\u9501\u7684\u63d0\u51fa\u4ec5\u4ec5\u662f\u4e3a\u4e86\u9632\u6b62\u63d2\u5165\u5e7b\u5f71\u8bb0\u5f55\u800c\u63d0\u51fa\u7684\u3002**\u867d\u7136\u6709<code>\u5171\u4eabgap\u9501<\/code>\u548c<code>\u72ec\u5360gap\u9501<\/code>\u8fd9\u6837\u7684\u8bf4\u6cd5\uff0c\u4f46\u662f\u5b83\u4eec\u8d77\u5230\u7684\u4f5c\u7528\u662f\u76f8\u540c\u7684\u3002\u800c\u4e14\u5982\u679c\u5bf9\u4e00\u6761\u8bb0\u5f55\u52a0\u4e86gap\u9501\uff08\u4e0d\u8bba\u662f\u5171\u4eabgap\u9501\u8fd8\u662f\u72ec\u5360gap\u9501\uff09\uff0c\u5e76\u4e0d\u4f1a\u9650\u5236\u5176\u4ed6\u4e8b\u52a1\u5bf9\u8fd9\u6761\u8bb0\u5f55\u52a0\u8bb0\u5f55\u9501\u6216\u8005\u7ee7\u7eed\u52a0gap\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u4f1a\u8bdd1 session1<\/th><th>\u4f1a\u8bdd2 session2<\/th><\/tr><\/thead><tbody><tr><td>BEGIN;<br>SELECT * FROM student WHERE id=5 LOCK IN SHARE MODE;<\/td><td><\/td><\/tr><tr><td><\/td><td>BEGIN<br>SELECT * FROM student WHERE id = 7 FOR UPDATE;<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u8fd9\u91cc session 2 \u5e76\u4e0d\u4f1a\u88ab\u5835\u4f4f\u3002\u56e0\u4e3a\u8868\u91cc\u5e76\u6ca1\u6709 id=5 \u8fd9\u4e2a\u8bb0\u5f55\uff0c\u56e0\u6b64 session 1 \u52a0\u7684\u662f\u95f4\u9699\u9501\uff083,8)\u3002\u800c session 2 \u4e5f\u662f\u5728\u8fd9\u4e2a\u95f4\u9699\u52a0\u7684\u95f4\u9699\u9501\u3002\u5b83\u4eec\u6709\u5171\u540c\u7684\u76ee\u6807\uff0c\u5373\uff0c\u4fdd\u62a4\u8fd9\u4e2a\u95f4\u9699\uff0c\u4e0d\u5141\u8bb8\u63d2\u5165\u503c\u3002\u4f46\uff0c\u5b83\u4eec\u4e4b\u95f4\u662f\u4e0d\u51b2\u7a81\u7684\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM performance_schema.data_locks\\G\n*************************** row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109607664:39:4:4:139647036503760\nENGINE_TRANSACTION_ID: 122366\n            THREAD_ID: 93\n             EVENT_ID: 20\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 139647036503760\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 8\n*************************** row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109606808:39:4:4:139647036497536\nENGINE_TRANSACTION_ID: 421122086317464\n            THREAD_ID: 92\n             EVENT_ID: 22\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 139647036497536\n            LOCK_TYPE: RECORD\n            LOCK_MODE: S,GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 8\n<\/code><\/pre>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u5b9e\u9645\u7ed3\u679c\u4f1a\u663e\u793a4\u628a\u9501\uff0c\u4e24\u628a\u610f\u5411\u9501 IS IX,\u4e24\u628a\u95f4\u9699\u9501<\/p>\n<\/blockquote>\n\n\n\n<p><strong>\u9501\u5b9a\u533a\u95f4 (\u6700\u540e\u4e00\u6761\u8bb0\u5f55,Supremum \u8bb0\u5f55)<\/strong><\/p>\n\n\n\n<p>\u7ed9\u4e00\u6761\u8bb0\u5f55\u52a0\u4e86<code>gap<\/code>\u9501\u540e\uff0c\u4e0d\u5141\u8bb8\u5176\u4ed6\u4e8b\u52a1\u5f80\u8fd9\u6761\u8bb0\u5f55\u524d\u8fb9\u7684\u95f4\u9699\u63d2\u5165\u65b0\u8bb0\u5f55\uff0c\u90a3\u5bf9\u4e8e\u6700\u540e\u4e00\u6761\u8bb0\u5f55\u4e4b\u540e\u7684\u95f4\u9699\uff0c\u4e5f\u5c31\u662fstudent\u8868\u4e2did\u503c\u4e3a20\u7684\u8bb0\u5f55\u4e4b\u540e\u7684\u95f4\u9699\u3002\u7ed9\u54ea\u6761\u8bb0\u5f55\u52a0gap\u9501\u624d\u80fd\u963b\u6b62\u5176\u4ed6\u4e8b\u52a1\u63d2\u5165id\u503c\u5728(20\uff0c\u6b63\u65e0\u7a77)\u8fd9\u4e2a\u533a\u95f4\u7684\u65b0\u8bb0\u5f55\u5462\uff1f\u8fd9\u65f6\u5019\u6211\u4eec\u5728\u8bb2\u6570\u636e\u9875\u65f6\u4ecb\u7ecd\u7684\u4e24\u6761\u4f2a\u8bb0\u5f55\u6d3e\u4e0a\u7528\u573a\u4e86\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>Infimum<\/code>\u8bb0\u5f55\uff0c\u8868\u793a\u8be5\u9875\u9762\u4e2d\u6700\u5c0f\u7684\u8bb0\u5f55\u3002<\/li>\n\n\n\n<li><code>Supremum<\/code>\u8bb0\u5f55\uff0c\u8868\u793a\u8be5\u9875\u9762\u4e2d\u6700\u5927\u7684\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u53ea\u8981\u9501\u5b9a\u7684\u8bb0\u5f55\u7684id\u503c\uff0c\u5927\u4e8e\u5f53\u524d\u6570\u636e\u5e93\u6700\u5927\u7684id\u503c\uff0c\u5c31\u53ef\u4ee5\u9501\u5b9a\u8be5\u95f4\u9699\u3002\u5b9e\u73b0\u963b\u6b62\u5176\u4ed6\u4e8b\u52a1\u63d2\u5165id\u503c\u5728(20,\u6b63\u65e0\u7a77)\u8fd9\u4e2a\u533a\u95f4\u7684\u65b0\u8bb0\u5f55<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>BEGIN;\nSELECT * FROM student WHERE id &gt;20 LOCK IN SHARE MODE;\n# \u6216\u8005\nSELECT * FROM student WHERE id = 25 FOR UPDATE;\n<\/code><\/pre>\n\n\n\n<p>\u68c0\u6d4b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM performance_schema.data_locks\\G\n*************************** row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109606808:39:4:1:139647036497536\nENGINE_TRANSACTION_ID: 122365\n            THREAD_ID: 88\n             EVENT_ID: 20\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 139647036497536\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: supremum pseudo-record<\/code><\/pre>\n\n\n\n<p><strong>\u95f4\u9699\u9501\u7684\u6b7b\u9501\u95ee\u9898<\/strong><\/p>\n\n\n\n<p>\u95f4\u9699\u9501\u7684\u5f15\u5165\uff0c\u53ef\u80fd\u4f1a\u5bfc\u81f4\u540c\u6837\u7684\u8bed\u53e5\u9501\u5b9a\u66f4\u5927\u7684\u8303\u56f4\uff0c\u5f71\u54cd\u5e76\u53d1\u5ea6\u3002\u4e0b\u9762\u7684\u4f8b\u5b50\u5c31\u4f1a\u4ea7\u751f\u6b7b\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u4f1a\u8bdd1<\/th><th>\u4f1a\u8bdd2<\/th><\/tr><\/thead><tbody><tr><td>BEGIN;<br>SELECT * FROM student WHERE id =5 FOR UPDATE;<\/td><td>BEGIN;<br>SELECT * FROM student WHERE id =5 FOR UPDATE;<\/td><\/tr><tr><td><\/td><td>INSERT INTO student VALUES(5,'test','\u4e8c\u73ed');#\u963b\u585e<\/td><\/tr><tr><td>INSERT INTO student VALUES(5,'test','\u4e8c\u73ed');#\u963b\u585e<br><code>ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction<\/code><\/td><td>\u63d2\u5165\u8bed\u53e5\u6267\u884c\u6210\u529f<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u4f1a\u8bdd 1 \u6267\u884c\u00a0<code>SELECT...FOR UPDATE<\/code>\u00a0\u8bed\u53e5\uff0c\u7531\u4e8e\u00a0<code>id=5<\/code>\u00a0\u7684\u8bb0\u5f55\u5e76\u4e0d\u5b58\u5728\uff0c\u56e0\u6b64\u4f1a\u52a0\u4e0a\u95f4\u9699\u9501\uff083,8\uff09\u3002<\/li>\n\n\n\n<li>\u4f1a\u8bdd 2 \u6267\u884c\u00a0<code>SELECT...FOR UPDATE<\/code>\u00a0\u8bed\u53e5\uff0c\u540c\u6837\u4f1a\u52a0\u4e0a\u95f4\u9699\u9501\uff083,8\uff09\u3002\u7531\u4e8e\u95f4\u9699\u9501\u4e4b\u95f4\u4e0d\u4f1a\u4ea7\u751f\u51b2\u7a81\uff0c\u56e0\u6b64\u8fd9\u6761\u8bed\u53e5\u53ef\u4ee5\u6267\u884c\u6210\u529f\u3002<\/li>\n\n\n\n<li>\u4f1a\u8bdd 2 \u8bd5\u56fe\u63d2\u5165\u4e00\u6761\u00a0<code>id=5<\/code>\u00a0\u7684\u8bb0\u5f55\uff0c\u88ab\u4f1a\u8bdd 1 \u7684\u95f4\u9699\u9501\u963b\u585e\u4e86\uff0c\u53ea\u597d\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\u3002<\/li>\n\n\n\n<li>\u4f1a\u8bdd 1 \u8bd5\u56fe\u63d2\u5165\u4e00\u6761\u00a0<code>id=5<\/code>\u00a0\u7684\u8bb0\u5f55\uff0c\u88ab\u4f1a\u8bdd 2 \u7684\u95f4\u9699\u9501\u963b\u585e\u4e86\uff0c\u4e5f\u53ea\u597d\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\u3002<\/li>\n<\/ol>\n\n\n\n<p>\u81f3\u6b64\uff0c\u4e24\u4e2a\u4f1a\u8bdd\u8fdb\u5165\u4e92\u76f8\u7b49\u5f85\u72b6\u6001\uff0c\u4ea7\u751f\u4e86\u6b7b\u9501\u3002\u5f53\u7136\uff0c<code>InnoDB<\/code>&nbsp;\u5b58\u50a8\u5f15\u64ce\u4e2d\u7684\u6b7b\u9501\u68c0\u6d4b\u673a\u5236\u9a6c\u4e0a\u5c31\u4f1a\u68c0\u6d4b\u5230\u8fd9\u5bf9\u6b7b\u9501\u5173\u7cfb\uff0c\u4f1a\u8bdd 1 \u4e2d\u7684&nbsp;<code>INSERT<\/code>&nbsp;\u8bed\u53e5\u4f1a\u8fd4\u56de\u62a5\u9519\u4fe1\u606f\u3002\u4f1a\u8bdd 2 \u4e2d\u7684\u8bed\u53e5\u8fd4\u56de\u63d2\u5165\u6210\u529f\u7684\u4fe1\u606f\u3002<\/p>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"3-\u4e34\u952e\u9501next-key-locks\">\u2462 \u4e34\u952e\u9501\uff08Next-Key Locks\uff09<\/h5>\n\n\n\n<p>\u6709\u65f6\u5019\u6211\u4eec\u65e2\u60f3<code>\u9501\u4f4f\u67d0\u6761\u8bb0\u5f55<\/code>\uff0c\u53c8\u60f3<code>\u963b\u6b62<\/code>\u5176\u4ed6\u4e8b\u52a1\u5728\u8be5\u8bb0\u5f55\u524d\u8fb9\u7684<code>\u95f4\u9699\u63d2\u5165\u65b0\u8bb0\u5f55<\/code>\uff0c\u6240\u4ee5InnoDB\u5c31\u63d0\u51fa\u4e86\u4e00\u79cd\u79f0\u4e4b\u4e3a<code>Next-Key Locks<\/code>\u7684\u9501\uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a<code>LOCK_ORDINARY<\/code>\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u7b80\u79f0\u4e3a<code>next-key\u9501<\/code>\u3002Next-Key Locks\u662f\u5728\u5b58\u50a8\u5f15\u64ce<code>innodb<\/code>\u3001\u4e8b\u52a1\u7ea7\u522b\u5728<code>\u53ef\u91cd\u590d\u8bfb<\/code>\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u7684\u6570\u636e\u5e93\u9501\uff0cinnodb\u9ed8\u8ba4\u7684\u9501\u5c31\u662fNext-Key locks\u3002<\/p>\n\n\n\n<p>\u6bd4\u5982\uff0c\u6211\u4eec\u628aid\u503c\u4e3a8\u7684\u90a3\u6761\u8bb0\u5f55\u52a0\u4e00\u4e2anext-key\u9501\u3002<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"335\" width=\"1106\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/1e9ec652aec743ed8aa59148542e9147.png\" alt=\"\"><\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><code>next-key<\/code>&nbsp;\u9501\u7684\u672c\u8d28\u5c31\u662f\u4e00\u4e2a\u8bb0\u5f55\u9501\u548c\u4e00\u4e2agap\u9501\u7684\u5408\u4f53\uff0c\u5b83\u65e2\u80fd\u4fdd\u62a4\u8be5\u6761\u8bb0\u5f55\uff0c\u53c8\u80fd\u963b\u6b62\u522b\u7684\u4e8b\u52a1\u5c06\u65b0\u8bb0\u5f55\u63d2\u5165\u88ab\u4fdd\u62a4\u8bb0\u5f55\u524d\u8fb9\u7684\u95f4\u9699\u3002<\/p>\n<\/blockquote>\n\n\n\n<pre class=\"wp-block-code\"><code>begin; \nselect * from student where id &lt;=8 and id &gt; 3 for update;\n<\/code><\/pre>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"4-\u63d2\u5165\u610f\u5411\u9501insert-intention-locks\">\u2463 \u63d2\u5165\u610f\u5411\u9501\uff08Insert Intention Locks\uff09<\/h5>\n\n\n\n<p>\u6211\u4eec\u8bf4\u4e00\u4e2a\u4e8b\u52a1\u5728<code>\u63d2\u5165<\/code>\u4e00\u6761\u8bb0\u5f55\u65f6\u9700\u8981\u5224\u65ad\u4e00\u4e0b\u63d2\u5165\u4f4d\u7f6e\u662f\u4e0d\u662f\u88ab\u522b\u7684\u4e8b\u52a1\u52a0\u4e86<code>gap\u9501<\/code>\uff08<code>next-key\u9501<\/code>\u4e5f\u5305\u542b<code>gap\u9501<\/code>\uff09\uff0c\u5982\u679c\u6709\u7684\u8bdd\uff0c\u63d2\u5165\u64cd\u4f5c\u9700\u8981\u7b49\u5f85\uff0c\u76f4\u5230\u62e5\u6709<code>gap\u9501<\/code>\u7684\u90a3\u4e2a\u4e8b\u52a1\u63d0\u4ea4\u3002<strong>InnoDB\u89c4\u5b9a\u4e8b\u52a1\u5728\u7b49\u5f85\u7684\u65f6\u5019\u4e5f\u9700\u8981\u5728\u5185\u5b58\u4e2d\u751f\u6210\u4e00\u4e2a\u9501\u7ed3\u6784<\/strong>\uff0c\u8868\u660e\u6709\u4e8b\u52a1\u60f3\u5728\u67d0\u4e2a<code>\u95f4\u9699<\/code>\u4e2d<code>\u63d2\u5165<\/code>\u65b0\u8bb0\u5f55\uff0c\u4f46\u662f\u73b0\u5728\u5728\u7b49\u5f85\u3002InnoDB\u5c31\u628a\u8fd9\u79cd\u7c7b\u578b\u7684\u9501\u547d\u540d\u4e3a<code>Insert Intention Locks<\/code>\uff0c\u5b98\u65b9\u7684\u7c7b\u578b\u540d\u79f0\u4e3a\uff1a<code>LOCK_INSERT_INTENTION<\/code>\uff0c\u6211\u4eec\u79f0\u4e3a<code>\u63d2\u5165\u610f\u5411\u9501<\/code>\u3002<\/p>\n\n\n\n<p>\u63d2\u5165\u610f\u5411\u9501\u662f\u5728\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\u884c\u524d\uff0c\u7531<code>INSERT\u64cd\u4f5c\u4ea7\u751f\u7684\u4e00\u79cd\u9501<\/code>\uff0c\u8be5\u9501\u7528\u4e8e\u8868\u793a\u63d2\u5165\u7684\u610f\u5411\u3002<\/p>\n\n\n\n<p><strong>\u63d2\u5165\u610f\u5411\u9501\u662f\u4e00\u79cd\u58f0\u660e\u5f0f\u7684\u9501\u3002\u63d2\u5165\u610f\u5411\u9501\u4e4b\u95f4\u4e92\u4e0d\u6392\u65a5\uff0c\u6240\u4ee5\u5373\u4f7f\u591a\u4e2a\u4e8b\u52a1\u5728\u540c\u4e00\u533a\u95f4\u63d2\u5165\u591a\u6761\u8bb0\u5f55\uff0c\u53ea\u8981\u8bb0\u5f55\u672c\u8eab (\u4e3b\u952e\u3001\u552f\u4e00\u7d22\u5f15) \u4e0d\u51b2\u7a81, \u90a3\u4e48\u4e8b\u52a1\u4e4b\u95f4\u5c31\u4e0d\u4f1a\u51fa\u73b0\u51b2\u7a81\u7b49\u5f85\u3002\u4e8b\u5b9e\u4e0a\u63d2\u5165\u610f\u5411\u9501\u5e76\u4e0d\u4f1a\u963b\u6b62\u522b\u7684\u4e8b\u52a1\u7ee7\u7eed\u83b7\u53d6\u8be5\u8bb0\u5f55\u4e0a\u4efb\u4f55\u7c7b\u578b\u7684\u9501\u3002<\/strong><\/p>\n\n\n\n<p><strong>\u63d2\u5165\u610f\u5411\u9501\u548c\u610f\u5411\u9501<\/strong><\/p>\n\n\n\n<p>\u867d\u7136\u63d2\u5165\u610f\u5411\u9501\u4e2d\u542b\u6709\u201c\u610f\u5411\u9501\u201d\u4e09\u4e2a\u5b57\uff0c\u4f46\u5b83\u4e0d\u540c\u4e8e\u610f\u5411\u9501\uff0c\u610f\u5411\u9501\u662f\u8868\u9501\u800c\u63d2\u5165\u610f\u5411\u9501\u662f\u884c\u9501\u3002<\/p>\n\n\n\n<p><strong>\u63d2\u5165\u610f\u5411\u9501\u4e00\u79cd\u7279\u6b8a\u7684\u95f4\u9699\u9501<\/strong><\/p>\n\n\n\n<p>\u63d2\u5165\u610f\u5411\u9501\u4e00\u79cd\u7279\u6b8a\u7684\u95f4\u9699\u9501\uff0c\u7528\u6765\u914d\u5408\u95f4\u9699\u9501\u6216\u4e34\u952e\u9501\u4e00\u8d77\u9632\u6b62\u5e7b\u8bfb\u64cd\u4f5c\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code> const ulint type_mode = \n              LOCK_X | \n              LOCK_GAP | \n              LOCK_INSERT_INTENTION;\n<\/code><\/pre>\n\n\n\n<p>\u5728\u6392\u4ed6\uff08LOCK_X\uff09\u95f4\u9699\u9501\uff08LOCK_GAP\uff09\u7684\u57fa\u7840\u4e0a\u589e\u52a0 LOCK_INSERT_INTENTION \u6807\u5fd7\uff0c\u5c31\u5f97\u5230\u4e86\u63d2\u5165\u610f\u5411\u9501\uff0c\u6240\u4ee5\uff0c\u4ece\u672c\u8d28\u4e0a\u6765\u8bf4\uff0c\u63d2\u5165\u610f\u5411\u9501\u662f\u4e2a\u7279\u6b8a\u7684\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<p>\u63d2\u5165\u610f\u5411\u9501\u4e5f\u4e0d\u540c\u4e8e\u666e\u901a\u95f4\u9699\u9501\uff0c\u63d2\u5165\u610f\u5411\u9501\uff0c\u662f\u4e00\u79cd\u58f0\u660e\u5f0f\u7684\u9501\uff0c\u7528\u6765\u544a\u77e5\u6570\u636e\u5e93\u5f53\u524d\u4e8b\u52a1\u6253\u7b97\u5728\u67d0\u4e2a\u95f4\u9699\u8fdb\u884c\u63d2\u5165\uff0c\u5b83\u4e0d\u963b\u6b62\u5176\u4ed6\u4e8b\u52a1\u7684\u63d2\u5165\u64cd\u4f5c\u3002\u800c\u95f4\u9699\u9501\u4f1a\u963b\u585e\u5176\u4ed6\u4e8b\u52a1\u7684\u63d2\u5165\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u5176\u4ed6\u4e8b\u52a1\u7684\u63d2\u5165\u64cd\u4f5c\u524d\uff0c\u4f1a\u83b7\u53d6\u63d2\u5165\u610f\u5411\u9501\uff0c\u95f4\u9699\u9501\u4f1a\u963b\u585e\u63d2\u5165\u610f\u5411\u9501\u7684\u83b7\u53d6\u3002<\/p>\n\n\n\n<p><strong>\u6848\u4f8b<\/strong><\/p>\n\n\n\n<p>\u4e3e\u4f8b\uff0c\u8868 student \u4e2d\u5b58\u5728id\u503c\u4e3a3\u548c8\u7684\u4e24\u6761\u8bb0\u5f55\uff0c\u4e24\u4e2a\u4e0d\u540c\u7684\u4e8b\u52a1\u5206\u522b\u8bd5\u56fe\u63d2\u5165id\u503c\u4e3a5\u548c6\u7684\u4e24\u6761\u8bb0\u5f55, \u6bcf\u4e2a\u4e8b\u52a1\u5728\u83b7\u53d6\u63d2\u5165\u884c\u4e0a\u7684\u72ec\u5360\u9501\u524d\uff0c\u90fd\u4f1a\u5148\u68c0\u67e5 (3,8) \u533a\u95f4\u5185\u7684\u95f4\u9699\u9501\u3002\u5982\u679c\u6b64\u65f6\u8be5\u533a\u95f4\u5185\u5b58\u5728\u95f4\u9699\u9501, \u90a3\u4e48 MySQL\u4f1a\u4e3a\u63d2\u5165\u8bb0\u5f55\u7684\u4e24\u4e2a\u4e8b\u52a1\u751f\u6210\u63d2\u5165\u610f\u5411\u9501, \u5e76\u4e14\u4f7f\u8fd9\u4e24\u4e2a\u4e8b\u52a1\u90fd\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\uff0c\u5b83\u4eec\u90fd\u8981\u7b49\u5f85\u95f4\u9699\u9501\u88ab\u91ca\u653e\u624d\u80fd\u7ee7\u7eed\u6267\u884c\u63d2\u5165\u64cd\u4f5c\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u56e0\u4e3a\u63d2\u5165\u7684\u8bb0\u5f55\u4e4b\u95f4\u5e76\u4e0d\u51b2\u7a81, \u6240\u4ee5\u4e24\u4e2a\u63d2\u5165\u8bb0\u5f55\u7684\u4e8b\u52a1\u4e4b\u95f4\u5e76\u4e0d\u4f1a\u4e92\u76f8\u963b\u585e\u3002<\/p>\n\n\n\n<p>\u73b0\u5728\u4e3aid\u503c\u4e3a8\u7684\u8bb0\u5f55\u52a0\u7684\u9501\u7684\u793a\u610f\u56fe\u5c31\u5982\u4e0b\u6240\u793a:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"633\" src=\"https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239848-image-1024x633.png\" alt=\"\" class=\"wp-image-932\" srcset=\"https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239848-image-1024x633.png 1024w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239848-image-300x185.png 300w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239848-image-768x475.png 768w, https:\/\/eve2333.top\/wp-content\/uploads\/2025\/04\/1745239848-image.png 1123w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>\u4ece\u56fe\u4e2d\u53ef\u4ee5\u770b\u5230\uff0c\u7531\u4e8eT1\u6301\u6709gap\u9501\uff0c\u6240\u4ee5T2\u548cT3\u9700\u8981\u751f\u6210\u4e00\u4e2a\u63d2\u5165\u610f\u5411\u9501\u7684\u9501\u7ed3\u6784\u5e76\u4e14\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\u3002\u5f53T1\u63d0\u4ea4\u540e\u4f1a\u628a\u5b83\u83b7\u53d6\u5230\u7684\u9501\u90fd\u91ca\u653e\u6389\uff0c\u8fd9\u6837T2\u548cT3\u5c31\u80fd\u83b7\u53d6\u5230\u5bf9\u5e94\u7684\u63d2\u5165\u610f\u5411\u9501\u4e86(\u672c\u8d28\u4e0a\u5c31\u662f\u628a\u63d2\u5165\u610f\u5411\u9501\u5bf9\u5e94\u9501\u7ed3\u6784\u7684is_waiting\u5c5e\u6027\u6539\u4e3afalse)\uff0cT2\u548cT3\u4e4b\u95f4\u4e5f\u5e76\u4e0d\u4f1a\u76f8\u4e92\u963b\u585e\uff0c\u5b83\u4eec\u53ef\u4ee5\u540c\u65f6\u83b7\u53d6\u5230id\u503c\u4e3a8\u7684\u63d2\u5165\u610f\u5411\u9501\uff0c\u7136\u540e\u6267\u884c\u63d2\u5165\u64cd\u4f5c\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>##############################SessionA####################################\n# \u8868\u7ea7\u9501IX\uff0c\u884c\u7ea7\u9501GAP\uff0cX\n# \u6210\u529f\u83b7\u53d6\u72b6\u6001\nbegin;\nselect * from student where id = 4 for update;\ncommit;\nSELECT * FROM performance_schema.data_locks\\G\n\n##############################SessionB####################################\n# \u8868\u7ea7\u9501\u7684IX\uff0c\u884c\u7ea7\u9501X,GAP,INSERT_INTENTION\n# \u7b49\u5f85\u72b6\u6001\nbegin;\ninsert into student(id,name,class) values(5,'Tim','\u4e00\u73ed');\n\n##############################SessionC####################################\n# \u8868\u7ea7\u9501\u7684IX\uff0c\u884c\u7ea7\u9501X,GAP,INSERT_INTENTION\n# \u7b49\u5f85\u72b6\u6001\nbegin;\ninsert into student(id,name,class) values(6,'Tim','\u4e00\u73ed');\n\n# \u4e8b\u52a1B\u548c\u4e8b\u52a1C\u540c\u65f6\u5904\u4e8e\u7b49\u5f85\u72b6\u6001\uff0c\u4e8b\u52a1A\u7684\u95f4\u9699\u9501\u963b\u585e\u4e86\u4e8b\u52a1B\u548cC\u7684\u63d2\u5165\u610f\u5411\u9501\n# \u4e8b\u52a1B\u548cC\u7684\u63d2\u5165\u610f\u5411\u9501\u4e0d\u51b2\u7a81\u3002\n\n# \u5982\u679c\u4e24\u4e2a\u4e8b\u52a1B\u548c\u4e8b\u52a1C\u5e76\u4e0d\u662f\u540c\u65f6\u88ab\u963b\u585e\uff0c\u5373\u4e8b\u52a1A\u63d0\u4ea4\u540e\uff0c\u4e8b\u52a1B\u963b\u585e\u7ed3\u675f\uff0c\u4e8b\u52a1C\u521a\u5f00\u59cbBEGIN\n# \u5219\u4e8b\u52a1B\u83b7\u5f97\u5230\u8868\u7ea7\u9501\u7684IX\uff0c\u884c\u7ea7\u9501X,GAP,INSERT_INTENTION\n# \u4e8b\u52a1C\u83b7\u53d6\u5230\u8868\u7ea7\u9501\u7684IX\u610f\u5411\u9501\u3002(\u63d2\u5165\u64cd\u4f5c\u4e00\u822c\u4e0d\u52a0\u9501\uff0c\u53ea\u6709\u4e00\u4e2a\u9690\u5f0f\u9501\uff0c\u8be6\u60c5\u770b\u4e0b\u9762\u7684\u9690\u5f0f\u9501)\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"323-\u9875\u9501\">3.2.3 \u9875\u9501<\/h4>\n\n\n\n<p>\u9875\u9501\u5c31\u662f\u5728<code>\u9875\u7684\u7c92\u5ea6<\/code>\u4e0a\u8fdb\u884c\u9501\u5b9a\uff0c\u9501\u5b9a\u7684\u6570\u636e\u8d44\u6e90\u6bd4\u884c\u9501\u8981\u591a\uff0c\u56e0\u4e3a\u4e00\u4e2a\u9875\u4e2d\u53ef\u4ee5\u6709\u591a\u4e2a\u884c\u8bb0\u5f55\u3002\u5f53\u6211\u4eec\u4f7f\u7528\u9875\u9501\u7684\u65f6\u5019\uff0c\u4f1a\u51fa\u73b0\u6570\u636e\u6d6a\u8d39\u7684\u73b0\u8c61\uff0c\u4f46\u8fd9\u6837\u7684\u6d6a\u8d39\u6700\u591a\u4e5f\u5c31\u662f\u4e00\u4e2a\u9875\u4e0a\u7684\u6570\u636e\u884c\u3002<strong>\u9875\u9501\u7684\u5f00\u9500\u4ecb\u4e8e\u8868\u9501\u548c\u884c\u9501\u4e4b\u95f4\uff0c\u4f1a\u51fa\u73b0\u6b7b\u9501\u3002\u9501\u5b9a\u7c92\u5ea6\u4ecb\u4e8e\u8868\u9501\u548c\u884c\u9501\u4e4b\u95f4\uff0c\u5e76\u53d1\u5ea6\u4e00\u822c\u3002<\/strong><\/p>\n\n\n\n<p>\u6bcf\u4e2a\u5c42\u7ea7\u7684\u9501\u6570\u91cf\u662f\u6709\u9650\u5236\u7684\uff0c\u56e0\u4e3a\u9501\u4f1a\u5360\u7528\u5185\u5b58\u7a7a\u95f4\uff0c<code>\u9501\u7a7a\u95f4\u7684\u5927\u5c0f\u662f\u6709\u9650\u7684<\/code>\u3002\u5f53\u67d0\u4e2a\u5c42\u7ea7\u7684\u9501\u6570\u91cf\u8d85\u8fc7\u4e86\u8fd9\u4e2a\u5c42\u7ea7\u7684\u9608\u503c\u65f6\uff0c\u5c31\u4f1a\u8fdb\u884c<code>\u9501\u5347\u7ea7<\/code>\u3002\u9501\u5347\u7ea7\u5c31\u662f\u7528\u66f4\u5927\u7c92\u5ea6\u7684\u9501\u66ff\u4ee3\u591a\u4e2a\u66f4\u5c0f\u7c92\u5ea6\u7684\u9501\uff0c\u6bd4\u5982InnoDB\u4e2d\u884c\u9501\u5347\u7ea7\u4e3a\u8868\u9501\uff0c\u8fd9\u6837\u505a\u7684\u597d\u5904\u662f\u5360\u7528\u7684\u9501\u7a7a\u95f4\u964d\u4f4e\u4e86\uff0c\u4f46\u540c\u65f6\u6570\u636e\u7684\u5e76\u53d1\u5ea6\u4e5f\u4e0b\u964d\u4e86\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"33-\u4ece\u5bf9\u5f85\u9501\u7684\u6001\u5ea6\u5212\u5206\u4e50\u89c2\u9501-\u60b2\u89c2\u9501\">3.3 \u4ece\u5bf9\u5f85\u9501\u7684\u6001\u5ea6\u5212\u5206:\u4e50\u89c2\u9501\u3001\u60b2\u89c2\u9501<\/h3>\n\n\n\n<p>\u4ece\u5bf9\u5f85\u9501\u7684\u6001\u5ea6\u6765\u770b\u9501\u7684\u8bdd\uff0c\u53ef\u4ee5\u5c06\u9501\u5206\u6210\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\uff0c\u4ece\u540d\u5b57\u4e2d\u4e5f\u53ef\u4ee5\u770b\u51fa\u8fd9\u4e24\u79cd\u9501\u662f\u4e24\u79cd\u770b\u5f85<code>\u6570\u636e\u5e76\u53d1\u7684\u601d\u7ef4\u65b9\u5f0f<\/code>\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\u5e76\u4e0d\u662f\u9501\uff0c\u800c\u662f\u9501\u7684<code>\u8bbe\u8ba1\u601d\u60f3<\/code>\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"1\u60b2\u89c2\u9501pessimistic-locking\">1\uff09\u60b2\u89c2\u9501\uff08Pessimistic Locking\uff09<\/h4>\n\n\n\n<p>\u60b2\u89c2\u9501\u662f\u4e00\u79cd\u601d\u60f3\uff0c\u987e\u540d\u601d\u4e49\uff0c\u5c31\u662f\u5f88\u60b2\u89c2\uff0c\u5bf9\u6570\u636e\u88ab\u5176\u4ed6\u4e8b\u52a1\u7684\u4fee\u6539\u4fdd\u6301\u4fdd\u5b88\u6001\u5ea6\uff0c\u4f9d\u9760\u6570\u636e\u5e93\u81ea\u8eab\u7684\u9501\u673a\u5236\u6765\u5b9e\u73b0\uff0c\u4ece\u800c\u4fdd\u8bc1\u6570\u636e\u64cd\u4f5c\u7684\u6392\u5b83\u6027\u3002<\/p>\n\n\n\n<p>\u60b2\u89c2\u9501\u603b\u662f\u5047\u8bbe\u6700\u574f\u7684\u60c5\u51b5\uff0c\u6bcf\u6b21\u53bb\u62ff\u6570\u636e\u7684\u65f6\u5019\u90fd\u8ba4\u4e3a\u522b\u4eba\u4f1a\u4fee\u6539\uff0c\u6240\u4ee5\u6bcf\u6b21\u5728\u62ff\u6570\u636e\u7684\u65f6\u5019\u90fd\u4f1a\u4e0a\u9501\uff0c\u8fd9\u6837\u522b\u4eba\u60f3\u62ff\u8fd9\u4e2a\u6570\u636e\u5c31\u4f1a<code>\u963b\u585e<\/code>\u76f4\u5230\u5b83\u62ff\u5230\u9501\uff08<strong>\u5171\u4eab\u8d44\u6e90\u6bcf\u6b21\u53ea\u7ed9\u4e00\u4e2a\u7ebf\u7a0b\u4f7f\u7528\uff0c\u5176\u5b83\u7ebf\u7a0b\u963b\u585e\uff0c\u7528\u5b8c\u540e\u518d\u628a\u8d44\u6e90\u8f6c\u8ba9\u7ed9\u5176\u5b83\u7ebf\u7a0b<\/strong>\uff09\u3002\u6bd4\u5982\u884c\u9501\uff0c\u8868\u9501\u7b49\uff0c\u8bfb\u9501\uff0c\u5199\u9501\u7b49\uff0c\u90fd\u662f\u5728\u505a\u64cd\u4f5c\u4e4b\u524d\u5148\u4e0a\u9501\uff0c\u5f53\u5176\u4ed6\u7ebf\u7a0b\u60f3\u8981\u8bbf\u95ee\u6570\u636e\u65f6\uff0c\u90fd\u9700\u8981\u963b\u585e\u6302\u8d77\u3002Java\u4e2d<code>synchronized<\/code>\u548c<code>ReentrantLock<\/code>\u7b49\u72ec\u5360\u9501\u5c31\u662f\u60b2\u89c2\u9501\u601d\u60f3\u7684\u5b9e\u73b0\u3002<\/p>\n\n\n\n<p><strong>\u79d2\u6740\u6848\u4f8b1<\/strong><\/p>\n\n\n\n<p>\u5728\u5546\u54c1\u79d2\u6740\u8fc7\u7a0b\u4e2d\uff0c\u5e93\u5b58\u6570\u91cf\u4f1a\u9010\u6e10\u51cf\u5c11\uff0c\u8981\u907f\u514d\u51fa\u73b0<code>\u8d85\u5356<\/code>\u7684\u60c5\u51b5\u3002\u6bd4\u5982\uff0c\u5546\u54c1\u8868\u4e2d\u6709\u4e00\u4e2a\u5b57\u6bb5\u4e3aquantity\uff0c\u8868\u793a\u5f53\u524d\u8be5\u5546\u54c1\u7684\u5e93\u5b58\u91cf\u3002\u5047\u8bbe\u5546\u54c1\u4e3a\u534e\u4e3amate40\uff0cid\u4e3a1001\uff0cquantity=100\u4e2a\u3002\u5982\u679c\u4e0d\u4f7f\u7528\u9501\u7684\u60c5\u51b5\u4e0b\uff0c\u64cd\u4f5c\u65b9\u6cd5\u5982\u4e0b\u6240\u793a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u7b2c1\u6b65\uff1a\u67e5\u51fa\u5546\u54c1\u5e93\u5b58\nselect quantity from items where id = 1001;\n#\u7b2c2\u6b65\uff1a\u5982\u679c\u5e93\u5b58\u5927\u4e8e0\uff0c\u5219\u6839\u636e\u5546\u54c1\u4fe1\u606f\u751f\u4ea7\u8ba2\u5355\ninsert into orders (item_id) values(1001);\n#\u7b2c3\u6b65\uff1a\u4fee\u6539\u5546\u54c1\u7684\u5e93\u5b58\uff0cnum\u8868\u793a\u8d2d\u4e70\u6570\u91cf\nupdate items set quantity = quantity - num where id = 1001;<\/code><\/pre>\n\n\n\n<p>\u8fd9\u6837\u5199\u7684\u8bdd\uff0c\u5728\u5e76\u53d1\u91cf\u5c0f\u7684\u516c\u53f8\u6ca1\u6709\u5927\u7684\u95ee\u9898\uff0c\u4f46\u662f\u5982\u679c\u5728<code>\u9ad8\u5e76\u53d1\u73af\u5883<\/code>\u4e0b\u53ef\u80fd\u51fa\u73b0\u4ee5\u4e0b\u95ee\u9898<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u5e8f\u53f7<\/th><th>\u7ebf\u7a0bA<\/th><th>\u7ebf\u7a0bB<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>step1\uff08\u67e5\u8be2\u8fd8\u6709100\u90e8\u624b\u673a\uff09<\/td><td>step1\uff08\u67e5\u8be2\u8fd8\u6709100\u90e8\u624b\u673a\uff09<\/td><\/tr><tr><td>2<\/td><td><\/td><td>step2\uff08\u751f\u6210\u8ba2\u5355\uff09<\/td><\/tr><tr><td>3<\/td><td>step2\uff08\u751f\u6210\u8ba2\u5355\uff09<\/td><td><\/td><\/tr><tr><td>4<\/td><td><\/td><td>step3\uff08\u51cf\u5e93\u5b581\uff0c\u51cf100\u53f0\uff09<\/td><\/tr><tr><td>5<\/td><td>step3\uff08\u51cf\u5e93\u5b582\uff0c\u51cf100\u53f0\uff09<\/td><td><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u5176\u4e2d\u7ebf\u7a0bB\u6b64\u65f6\u5df2\u7ecf\u4e0b\u5355\u5e76\u4e14\u51cf\u5b8c\u5e93\u5b58\uff0c\u8fd9\u4e2a\u65f6\u5019\u7ebf\u7a0bA\u4f9d\u7136\u6839\u636e\u5b83\u6700\u521d\u67e5\u8be2\u5230\u7684\u5e93\u5b58\uff08100\u53f0\uff09\u53bb\u6267\u884cstep3\uff0c\u5c31\u9020\u6210\u4e86\u8d85\u5356\uff01<\/p>\n\n\n\n<p>\u6211\u4eec\u4f7f\u7528\u60b2\u89c2\u9501\u53ef\u4ee5\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u5546\u54c1\u4fe1\u606f\u4ece\u67e5\u8be2\u51fa\u6765\u5230\u4fee\u6539\uff0c\u4e2d\u95f4\u6709\u4e00\u4e2a\u751f\u6210\u8ba2\u5355\u7684\u8fc7\u7a0b\uff0c\u4f7f\u7528\u60b2\u89c2\u9501\u7684\u539f<br>\u7406\u5c31\u662f\uff0c\u5f53\u6211\u4eec\u5728\u67e5\u8be2items\u4fe1\u606f\u540e\u5c31\u628a\u5f53\u524d\u7684\u6570\u636e\u9501\u5b9a\uff0c\u76f4\u5230\u6211\u4eec\u4fee\u6539\u5b8c\u6bd5\u540e\u518d\u89e3\u9501\u3002\u90a3\u4e48\u6574\u4e2a\u8fc7\u7a0b\u4e2d\uff0c\u56e0\u4e3a\u6570\u636e\u88ab\u9501\u5b9a\u4e86\uff0c\u5c31\u4e0d\u4f1a\u51fa\u73b0\u6709\u7b2c\u4e09\u8005\u6765\u5bf9\u5176\u8fdb\u884c\u4fee\u6539\u4e86\u3002\u800c\u8fd9\u6837\u505a\u7684\u524d\u63d0\u662f<strong>\u9700\u8981\u5c06\u8981\u6267\u884c\u7684SQL\u8bed\u53e5\u653e\u5728\u540c\u4e00\u4e2a\u4e8b\u52a1\u4e2d\uff0c\u5426\u5219\u8fbe\u4e0d\u5230\u9501\u5b9a\u6570\u636e\u7684\u76ee\u7684\u3002<\/strong><\/p>\n\n\n\n<p>\u4fee\u6539\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u7b2c1\u6b65\uff1a\u67e5\u51fa\u5546\u54c1\u5e93\u5b58\nselect quantity from items where id = 1001 for update;\n#\u7b2c2\u6b65\uff1a\u5982\u679c\u5e93\u5b58\u5927\u4e8e0\uff0c\u5219\u6839\u636e\u5546\u54c1\u4fe1\u606f\u751f\u4ea7\u8ba2\u5355\ninsert into orders (item_id) values(1001);\n#\u7b2c3\u6b65\uff1a\u4fee\u6539\u5546\u54c1\u7684\u5e93\u5b58\uff0cnum\u8868\u793a\u8d2d\u4e70\u6570\u91cf\nupdate items set quantity = quantity - num where id = 1001;<\/code><\/pre>\n\n\n\n<p><code>select .... for update<\/code>\u662fMySQL\u4e2d\u60b2\u89c2\u9501\u3002\u6b64\u65f6\u5728items\u8868\u4e2d\uff0cid\u4e3a1001\u7684\u90a3\u6761\u6570\u636e\u5c31\u88ab\u6211\u4eec\u9501\u5b9a\u4e86\uff0c\u5176\u4ed6\u7684\u8981\u6267\u884c<code>select quantity from items where id = 1001 for update;<\/code>\u8bed\u53e5\u7684\u4e8b\u52a1\u5fc5\u987b\u7b49\u672c\u6b21\u4e8b\u52a1\u63d0\u4ea4\u4e4b\u540e\u624d\u80fd\u6267\u884c\u3002\u8fd9\u6837\u6211\u4eec\u53ef\u4ee5\u4fdd\u8bc1\u5f53\u524d\u7684\u6570\u636e\u4e0d\u4f1a\u88ab\u5176\u5b83\u4e8b\u52a1\u4fee\u6539\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u6ce8\u610f\uff0c\u5f53\u6267\u884c<code>select quantity from items where id = 1001 for update;<\/code>\u8bed\u53e5\u4e4b\u540e\uff0c\u5982\u679c\u5728\u5176\u4ed6\u4e8b\u52a1\u4e2d\u6267\u884c<code>select quantity from items where id = 1001;<\/code>\u8bed\u53e5\uff0c\u5e76\u4e0d\u4f1a\u53d7\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u7684\u5f71\u54cd\uff0c\u4ecd\u7136\u53ef\u4ee5\u6b63\u5e38\u67e5\u8be2\u51fa\u6570\u636e\u3002\u4e0d\u8fc7\u8bfb\u53d6\u7684\u6570\u636e\u53ef\u80fd\u662f\u5df2\u63d0\u4ea4\u7684\u65e7\u503c\uff0c\u5177\u4f53\u53d6\u51b3\u4e8e\u6570\u636e\u5e93\u7684\u9694\u79bb\u7ea7\u522b\u3002<\/p>\n<\/blockquote>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>[!important]<\/p>\n\n\n\n<p>\u6ce8\u610f: select .... for update\u8bed\u53e5\u6267\u884c\u8fc7\u7a0b\u4e2d\u6240\u6709\u626b\u63cf\u7684\u884c\u90fd\u4f1a\u88ab\u9501\u4e0a\uff0c\u56e0\u6b64\u5728MySQL\u4e2d\u7528\u60b2\u89c2\u9501\u5fc5\u987b\u786e\u5b9a\u4f7f\u7528\u4e86\u7d22\u5f15\uff0c\u800c\u4e0d\u662f\u5168\u8868\u626b\u63cf\uff0c\u5426\u5219\u5c06\u4f1a\u628a\u6574\u4e2a\u8868\u9501\u4f4f\u3002<\/p>\n<\/blockquote>\n\n\n\n<p>\u60b2\u89c2\u9501\u4e0d\u9002\u7528\u7684\u573a\u666f\u8f83\u591a\uff0c\u5b83\u5b58\u5728\u4e00\u4e9b\u4e0d\u8db3\uff0c\u56e0\u4e3a\u60b2\u89c2\u9501\u5927\u591a\u6570\u60c5\u51b5\u4e0b\u4f9d\u9760\u6570\u636e\u5e93\u7684\u9501\u673a\u5236\u6765\u5b9e\u73b0\uff0c\u4ee5\u4fdd\u8bc1\u7a0b\u5e8f<br>\u7684\u5e76\u53d1\u8bbf\u95ee\u6027\uff0c\u540c\u65f6\u8fd9\u6837\u5bf9\u6570\u636e\u5e93\u6027\u80fd\u7684\u6253\u5f71\u54cd\u4e5f\u5f88\u5927\uff0c\u7279\u522b\u662f<code>\u957f\u4e8b\u52a1<\/code>\u800c\u8a00\uff0c\u8fd9\u6837\u7684<code>\u5f00\u9500\u5f80\u5f80\u65e0\u6cd5\u627f\u53d7<\/code>\uff0c\u8fd9\u65f6\u5c31\u9700\u8981\u4e50\u89c2\u9501\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"2\u4e50\u89c2\u9501optimistic-locking\">2\uff09\u4e50\u89c2\u9501\uff08Optimistic Locking\uff09<\/h4>\n\n\n\n<p>\u4e50\u89c2\u9501\u8ba4\u4e3a\u5bf9\u540c\u4e00\u6570\u636e\u7684\u5e76\u53d1\u64cd\u4f5c\u4e0d\u4f1a\u603b\u53d1\u751f\uff0c\u5c5e\u4e8e\u5c0f\u6982\u7387\u4e8b\u4ef6\uff0c\u4e0d\u7528\u6bcf\u6b21\u90fd\u5bf9\u6570\u636e\u4e0a\u9501\uff0c\u4f46\u662f\u5728\u66f4\u65b0\u7684\u65f6\u5019\u4f1a\u5224\u65ad\u4e00\u4e0b\u5728\u6b64\u671f\u95f4\u522b\u4eba\u6709\u6ca1\u6709\u53bb\u66f4\u65b0\u8fd9\u4e2a\u6570\u636e\uff0c\u4e5f\u5c31\u662f<strong>\u4e0d\u91c7\u7528\u6570\u636e\u5e93\u81ea\u8eab\u7684\u9501\u673a\u5236\uff0c\u800c\u662f\u901a\u8fc7\u7a0b\u5e8f\u6765\u5b9e\u73b0<\/strong>\u3002\u5728\u7a0b\u5e8f\u4e0a\uff0c\u6211\u4eec\u53ef\u4ee5\u91c7\u7528<code>\u7248\u672c\u53f7\u673a\u5236<\/code>\u6216\u8005<code>CAS\u673a\u5236<\/code>\u5b9e\u73b0\u3002<strong>\u4e50\u89c2\u9501\u9002\u7528\u4e8e\u591a\u8bfb\u7684\u5e94\u7528\u7c7b\u578b\uff0c\u8fd9\u6837\u53ef\u4ee5\u63d0\u9ad8\u541e\u5410\u91cf<\/strong>\u3002\u5728Java\u4e2d<code>java.util.concurrent.atomic<\/code>\u5305\u4e0b\u7684\u539f\u5b50\u53d8\u91cf\u7c7b\u5c31\u662f\u4f7f\u7528\u4e86\u4e50\u89c2\u9501\u7684\u4e00\u79cd\u5b9e\u73b0\u65b9\u5f0f\uff1aCAS\u5b9e\u73b0\u7684\u3002<\/p>\n\n\n\n<p><strong>\u2460 \u4e50\u89c2\u9501\u7684\u7248\u672c\u53f7\u673a\u5236<\/strong><\/p>\n\n\n\n<p>\u5728\u8868\u4e2d\u8bbe\u8ba1\u4e00\u4e2a<code>\u7248\u672c\u5b57\u6bb5 version<\/code>\uff0c\u7b2c\u4e00\u6b21\u8bfb\u7684\u65f6\u5019\uff0c\u4f1a\u83b7\u53d6 version \u5b57\u6bb5\u7684\u53d6\u503c\u3002\u7136\u540e\u5bf9\u6570\u636e\u8fdb\u884c\u66f4\u65b0\u6216\u5220\u9664\u64cd\u4f5c\u65f6\uff0c\u4f1a\u6267\u884c<code>UPDATE ... SET version=version+1 WHERE version=version<\/code>\u3002\u6b64\u65f6\u5982\u679c\u5df2\u7ecf\u6709\u4e8b\u52a1\u5bf9\u8fd9\u6761\u6570\u636e\u8fdb\u884c\u4e86\u66f4\u6539\uff0c\u4fee\u6539\u5c31\u4e0d\u4f1a\u6210\u529f\u3002<\/p>\n\n\n\n<p><strong>\u2461 \u4e50\u89c2\u9501\u7684\u65f6\u95f4\u6233\u673a\u5236<\/strong><\/p>\n\n\n\n<p>\u65f6\u95f4\u6233\u548c\u7248\u672c\u53f7\u673a\u5236\u4e00\u6837\uff0c\u4e5f\u662f\u5728\u66f4\u65b0\u63d0\u4ea4\u7684\u65f6\u5019\uff0c\u5c06\u5f53\u524d\u6570\u636e\u7684\u65f6\u95f4\u6233\u548c\u66f4\u65b0\u4e4b\u524d\u53d6\u5f97\u7684\u65f6\u95f4\u6233\u8fdb\u884c\u6bd4\u8f83\uff0c\u5982\u679c\u4e24\u8005\u4e00\u81f4\u5219\u66f4\u65b0\u6210\u529f\uff0c\u5426\u5219\u5c31\u662f\u7248\u672c\u51b2\u7a81\u3002<\/p>\n\n\n\n<p>\u4f60\u80fd\u770b\u5230\u4e50\u89c2\u9501\u5c31\u662f\u7a0b\u5e8f\u5458\u81ea\u5df1\u63a7\u5236\u6570\u636e\u5e76\u53d1\u64cd\u4f5c\u7684\u6743\u9650\uff0c\u57fa\u672c\u662f\u901a\u8fc7\u7ed9\u6570\u636e\u884c\u589e\u52a0\u4e00\u4e2a\u6233\uff08\u7248\u672c\u53f7\u6216\u8005\u65f6\u95f4\u6233\uff09\uff0c\u4ece\u800c\u8bc1\u660e\u5f53\u524d\u62ff\u5230\u7684\u6570\u636e\u662f\u5426\u6700\u65b0\u3002<\/p>\n\n\n\n<p><strong>\u79d2\u6740\u6848\u4f8b2<\/strong><\/p>\n\n\n\n<p>\u4f9d\u7136\u4f7f\u7528\u4e0a\u9762\u79d2\u6740\u7684\u6848\u4f8b\uff0c\u6267\u884c\u6d41\u7a0b\u5982\u4e0b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u7b2c1\u6b65\uff1a\u67e5\u51fa\u5546\u54c1\u5e93\u5b58\nselect quantity from items where id = 1001;\n\n#\u7b2c2\u6b65\uff1a\u5982\u679c\u5e93\u5b58\u5927\u4e8e0\uff0c\u5219\u6839\u636e\u5546\u54c1\u4fe1\u606f\u751f\u4ea7\u8ba2\u5355\ninsert into orders (item_id) values(1001);\n\n#\u7b2c3\u6b65\uff1a\u4fee\u6539\u5546\u54c1\u7684\u5e93\u5b58\uff0cnum\u8868\u793a\u8d2d\u4e70\u6570\u91cf\nupdate items set quantity = quantity-num,version = version+1 where id = 1001 and version = # {version};<\/code><\/pre>\n\n\n\n<p>\u6ce8\u610f\uff0c\u5982\u679c\u6570\u636e\u8868\u662f<code>\u8bfb\u5199\u5206\u79bb<\/code>\u7684\u8868\uff0c\u5f53master\u8868\u4e2d\u5199\u5165\u7684\u6570\u636e\u6ca1\u6709\u53ca\u65f6\u540c\u6b65\u5230slave\u8868\u4e2d\u65f6\uff0c\u4f1a\u9020\u6210\u66f4\u65b0\u4e00\u76f4\u5931\u8d25\u7684\u95ee\u9898\u3002\u6b64\u65f6\u9700\u8981<code>\u5f3a\u5236\u8bfb\u53d6master\u8868<\/code>\u4e2d\u7684\u6570\u636e\uff08\u5373\u5c06select\u8bed\u53e5\u653e\u5230\u4e8b\u52a1\u4e2d\u5373\u53ef\uff0c\u8fd9\u65f6\u5019\u67e5\u8be2\u7684\u5c31\u662fmaster\u4e3b\u5e93\u4e86\u3002\uff09<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u8bfb\u5199\u5206\u79bb\u65f6\uff0c\u4e3b\u673a\u8d1f\u8d23\u5199\uff0c\u4ece\u673a\u8d1f\u8d23\u8bfb<\/p>\n\n\n\n<p>\u4ece\u673a\u8bfb\u53d6\u5230\u65e7\u7684\u7248\u672c\u53f7version1\uff0c\u4f46\u662f\u4e3b\u673a\u4e0a\u7684\u7248\u672c\u53f7\uff0c\u5df2\u7ecf\u66f4\u65b0\u8fc7\u4e86\uff0c\u66f4\u65b0\u5230\u4e86version3\u3002<\/p>\n\n\n\n<p>\u5bfc\u81f4\u66f4\u65b0\u64cd\u4f5c\u5931\u8d25\uff0c\u56e0\u4e3aversion1!=version3<\/p>\n\n\n\n<p>\u91cd\u65b0\u5230\u4ece\u673a\u8bfb\u53d6\u7248\u672c\u53f7\uff0c\u56e0\u4e3a\u4ece\u673a\u6ca1\u53ca\u65f6\u66f4\u65b0\u6570\u636e\uff0c\u53c8\u8bfb\u53d6\u5230\u7248\u672c\u53f7version1\uff0c\u518d\u6b21\u66f4\u65b0\u5931\u8d25\u3002<\/p>\n<\/blockquote>\n\n\n\n<p>\u5982\u679c\u6211\u4eec\u5bf9\u540c\u4e00\u6761\u6570\u636e\u8fdb\u884c<code>\u9891\u7e41\u7684\u4fee\u6539<\/code>\u7684\u8bdd\uff0c\u90a3\u4e48\u5c31\u4f1a\u51fa\u73b0\u8fd9\u4e48\u4e00\u79cd\u573a\u666f\uff0c\u6bcf\u6b21\u4fee\u6539\u90fd\u53ea\u6709\u4e00\u4e2a\u4e8b\u52a1\u80fd\u66f4\u65b0\u6210\u529f\uff0c\u5728\u4e1a\u52a1\u611f\u77e5\u4e0a\u9762\u5c31\u6709\u5927\u91cf\u7684\u5931\u8d25\u64cd\u4f5c\u3002\u6211\u4eec\u628a\u4ee3\u7801\u4fee\u6539\u5982\u4e0b:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u7b2c1\u6b65\uff1a\u67e5\u51fa\u5546\u54c1\u5e93\u5b58\nselect quantity from items where id = 1001;\n\n#\u7b2c2\u6b65\uff1a\u5982\u679c\u5e93\u5b58\u5927\u4e8e0\uff0c\u5219\u6839\u636e\u5546\u54c1\u4fe1\u606f\u751f\u4ea7\u8ba2\u5355\ninsert into orders (item_id) values(1001);\n\n#\u7b2c3\u6b65\uff1a\u4fee\u6539\u5546\u54c1\u7684\u5e93\u5b58\uff0cnum\u8868\u793a\u8d2d\u4e70\u6570\u91cf\nupdate items set quantity = quantity-num where id = 1001 and quantity-num&gt;0;\n<\/code><\/pre>\n\n\n\n<p>\u8fd9\u6837\u5c31\u4f1a\u4f7f\u6bcf\u6b21\u4fee\u6539\u90fd\u80fd\u6210\u529f\uff0c\u800c\u4e14\u4e0d\u4f1a\u51fa\u73b0\u8d85\u5356\u7684\u73b0\u8c61\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u5b58\u7591\uff0c\u731c\u6d4b\u5982\u4e0b<\/p>\n\n\n\n<p>UPDATE\u4f1a\u83b7\u53d6\u5f53\u524d\u8bb0\u5f55\u884c\u7684X\u9501\uff0c\u6bcf\u6b21\u53ea\u6709\u4e00\u4e2a\u4e8b\u52a1\uff0c\u6301\u6709\u5f53\u524d\u8bb0\u5f55\u884c\u7684X\u9501\u3002\u53ef\u4ee5\u907f\u514d\u8d85\u5356\u3002<\/p>\n\n\n\n<p>\u4e5f\u5c31\u662f\u91c7\u53d6\u4e86\u60b2\u89c2\u9501\u7684\u7b56\u7565\u3002<\/p>\n<\/blockquote>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"3\u4e24\u79cd\u9501\u7684\u9002\u7528\u573a\u666f\">3\uff09\u4e24\u79cd\u9501\u7684\u9002\u7528\u573a\u666f<\/h4>\n\n\n\n<p>\u4ece\u8fd9\u4e24\u79cd\u9501\u7684\u8bbe\u8ba1\u601d\u60f3\u4e2d\uff0c\u6211\u4eec\u603b\u7ed3\u4e00\u4e0b\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\u7684\u9002\u7528\u573a\u666f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>\u4e50\u89c2\u9501<\/code>\u9002\u5408<code>\u8bfb\u64cd\u4f5c\u591a<\/code>\u7684\u573a\u666f\uff0c\u76f8\u5bf9\u6765\u8bf4\u5199\u7684\u64cd\u4f5c\u6bd4\u8f83\u5c11\u3002\u5b83\u7684\u4f18\u70b9\u5728\u4e8e<code>\u7a0b\u5e8f\u5b9e\u73b0<\/code>\uff0c<code>\u4e0d\u5b58\u5728\u6b7b\u9501<\/code>\u95ee\u9898\uff0c\u4e0d\u8fc7\u9002\u7528\u573a\u666f\u4e5f\u4f1a\u76f8\u5bf9\u4e50\u89c2\uff0c\u56e0\u4e3a\u5b83\u963b\u6b62\u4e0d\u4e86\u9664\u4e86\u7a0b\u5e8f\u4ee5\u5916\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u3002<\/li>\n\n\n\n<li><code>\u60b2\u89c2\u9501<\/code>\u9002\u5408<code>\u5199\u64cd\u4f5c\u591a<\/code>\u7684\u573a\u666f\uff0c\u56e0\u4e3a\u5199\u7684\u64cd\u4f5c\u5177\u6709<code>\u6392\u5b83\u6027<\/code>\u3002\u91c7\u7528\u60b2\u89c2\u9501\u7684\u65b9\u5f0f\uff0c\u53ef\u4ee5\u5728\u6570\u636e\u5e93\u5c42\u9762\u963b\u6b62\u5176\u4ed6\u4e8b\u52a1\u5bf9\u8be5\u6570\u636e\u7684\u64cd\u4f5c\u6743\u9650\uff0c\u9632\u6b62<code>\u8bfb - \u5199<\/code>\u548c<code>\u5199 - \u5199<\/code>\u7684\u51b2\u7a81\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u6211\u4eec\u628a\u4e50\u89c2\u9501\u548c\u60b2\u89c2\u9501\u603b\u7ed3\u5982\u4e0b\u56fe\u6240\u793a\u3002<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"375\" width=\"949\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/d703184cb10745a2acdd6a22a068993c.png\" alt=\"\"><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"34-\u6309\u52a0\u9501\u7684\u65b9\u5f0f\u5212\u5206\u663e\u5f0f\u9501-\u9690\u5f0f\u9501\">3.4 \u6309\u52a0\u9501\u7684\u65b9\u5f0f\u5212\u5206\uff1a\u663e\u5f0f\u9501\u3001\u9690\u5f0f\u9501<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"1\u9690\u5f0f\u9501\">1\uff09\u9690\u5f0f\u9501<\/h4>\n\n\n\n<p>\u4e00\u4e2a\u4e8b\u52a1\u5728\u6267\u884c<code>INSERT<\/code>\u64cd\u4f5c\u65f6\uff0c\u5982\u679c\u5373\u5c06\u63d2\u5165\u7684<code>\u95f4\u9699<\/code>\u5df2\u7ecf\u88ab\u5176\u4ed6\u4e8b\u52a1\u52a0\u4e86gap\u9501\uff0c\u90a3\u4e48\u672c\u6b21INSERT\u64cd\u4f5c\u4f1a\u963b\u585e\uff0c\u5e76\u4e14\u5f53\u524d\u4e8b\u52a1\u4f1a\u5728\u8be5\u95f4\u9699\u4e0a\u52a0\u4e00\u4e2a\u63d2\u5165\u610f\u5411\u9501\uff0c\u5426\u5219\u4e00\u822c\u60c5\u51b5\u4e0bINSERT\u64cd\u4f5c\u662f\u4e0d\u52a0\u9501\u7684\u3002<\/p>\n\n\n\n<p>\u90a3\u5982\u679c\u4e00\u4e2a\u4e8b\u52a1\u9996\u5148\u63d2\u5165\u4e86\u4e00\u6761\u8bb0\u5f55\uff08\u6b64\u65f6\u5e76\u6ca1\u6709\u5728\u5185\u5b58\u4e2d\u5b58\u5728\u4e0e\u8be5\u8bb0\u5f55\u5173\u8054\u7684\u9501\u7ed3\u6784\uff09\uff0c\u7136\u540e\u53e6\u4e00\u4e2a\u4e8b\u52a1\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7acb\u5373\u4f7f\u7528<code>SELECT ... LOCK IN SHARE MODE<\/code>\u8bed\u53e5\u8bfb\u53d6\u8fd9\u6761\u8bb0\u5f55\uff0c\u4e5f\u5c31\u662f\u8981\u83b7\u53d6\u8fd9\u6761\u8bb0\u5f55\u7684S\u9501\uff0c\u6216\u8005\u4f7f\u7528<code>SELECT ... FOR UPDATE<\/code>\u8bed\u53e5\u8bfb\u53d6\u8fd9\u6761\u8bb0\u5f55\uff0c\u4e5f\u5c31\u662f\u8981\u83b7\u53d6\u8fd9\u6761\u8bb0\u5f55\u7684X\u9501\uff0c\u600e\u4e48\u529e\uff1f \u5982\u679c\u5141\u8bb8\u8fd9\u79cd\u60c5\u51b5\u7684\u53d1\u751f\uff0c\u90a3\u4e48\u53ef\u80fd\u4ea7\u751f\u810f\u8bfb\u95ee\u9898\u3002<\/li>\n\n\n\n<li>\u7acb\u5373\u4fee\u6539\u8fd9\u6761\u8bb0\u5f55\uff0c\u4e5f\u5c31\u662f\u8981\u83b7\u53d6\u8fd9\u6761\u8bb0\u5f55\u7684X\u9501\uff0c\u600e\u4e48\u529e\uff1f \u5982\u679c\u5141\u8bb8\u8fd9\u79cd\u60c5\u51b5\u7684\u53d1\u751f\uff0c\u90a3\u4e48\u53ef\u80fd\u4ea7\u751f\u810f\u5199\u7684\u95ee\u9898\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u8fd9\u65f6\u5019\u6211\u4eec\u8981\u628a\u8fc7\u7a0b\u4e2d\u7684<code>\u4e8b\u52a1id<\/code>\u53c8\u8981\u8d77\u4f5c\u7528\u4e86\u3002\u6211\u4eec\u628a\u805a\u7c07\u7d22\u5f15\u548c\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u7684\u8bb0\u5f55\u5206\u5f00\u770b\u4e00\u4e0b\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>**\u60c5\u666f\u4e00\uff1a**\u5bf9\u4e8e\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u6765\u8bf4\uff0c\u6709\u4e00\u4e2a<code>trx_id<\/code>\u9690\u85cf\u5217\uff0c\u8be5\u9690\u85cf\u5217\u8bb0\u5f55\u7740\u6700\u540e\u6539\u52a8\u8be5\u8bb0\u5f55\u7684<code>\u4e8b\u52a1id<\/code>\u3002\u90a3\u4e48\u5982\u679c\u5728\u5f53\u524d\u4e8b\u52a1\u4e2d\u65b0\u63d2\u5165\u4e00\u6761\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u540e\uff0c\u8be5\u8bb0\u5f55\u7684<code>trx_id<\/code>\u9690\u85cf\u5217\u4ee3\u8868\u7684\u7684\u5c31\u662f\u5f53\u524d\u4e8b\u52a1\u7684<code>\u4e8b\u52a1id<\/code>\uff0c\u5982\u679c\u5176\u4ed6\u4e8b\u52a1\u6b64\u65f6\u60f3\u5bf9\u8be5\u8bb0\u5f55\u6dfb\u52a0<code>S\u9501<\/code>\u6216\u8005<code>X\u9501<\/code>\u65f6\uff0c\u9996\u5148\u4f1a\u770b\u4e00\u4e0b\u8be5\u8bb0\u5f55\u7684<code>trx_id<\/code>\u9690\u85cf\u5217\u4ee3\u8868\u7684\u4e8b\u52a1\u662f\u5426\u662f\u5f53\u524d\u7684\u6d3b\u8dc3\u4e8b\u52a1\uff0c\u5982\u679c\u662f\u7684\u8bdd\uff0c\u90a3\u4e48\u5c31\u5e2e\u52a9\u5f53\u524d\u4e8b\u52a1\u521b\u5efa\u4e00\u4e2a<code>X\u9501<\/code>\uff08\u4e5f\u5c31\u662f\u4e3a\u5f53\u524d\u4e8b\u52a1\u521b\u5efa\u4e00\u4e2a\u9501\u7ed3\u6784\uff0c<code>is_waiting<\/code>\u5c5e\u6027\u662f<code>false<\/code>\uff09\uff0c\u7136\u540e\u81ea\u5df1\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\uff08\u4e5f\u5c31\u662f\u4e3a\u81ea\u5df1\u4e5f\u521b\u5efa\u4e00\u4e2a\u9501\u7ed3\u6784\uff0c<code>is_waiting<\/code>\u5c5e\u6027\u662f<code>true<\/code>\uff09\u3002<\/li>\n\n\n\n<li>**\u60c5\u666f\u4e8c\uff1a**\u5bf9\u4e8e\u4e8c\u7ea7\u7d22\u5f15\u8bb0\u5f55\u6765\u8bf4\uff0c\u672c\u8eab\u5e76\u6ca1\u6709<code>trx_id<\/code>\u9690\u85cf\u5217\uff0c\u4f46\u662f\u5728\u4e8c\u7ea7\u7d22\u5f15\u9875\u9762\u7684<code>Page Header<\/code>\u90e8\u5206\u6709\u4e00\u4e2a<code>PAGE_MAX_TRX_ID<\/code>\u5c5e\u6027\uff0c\u8be5\u5c5e\u6027\u4ee3\u8868\u5bf9\u8be5\u9875\u9762\u505a\u6539\u52a8\u7684\u6700\u5927\u7684<code>\u4e8b\u52a1id<\/code>\uff0c\u5982\u679c<code>PAGE_MAX_TRX_ID<\/code>\u5c5e\u6027\u503c\u5c0f\u4e8e\u5f53\u524d\u6700\u5c0f\u7684\u6d3b\u8dc3<code>\u4e8b\u52a1id<\/code>\uff0c\u90a3\u4e48\u8bf4\u660e\u5bf9\u8be5\u9875\u9762\u505a\u4fee\u6539\u7684\u4e8b\u52a1\u90fd\u5df2\u7ecf\u63d0\u4ea4\u4e86\uff0c\u5426\u5219\u5c31\u9700\u8981\u5728\u9875\u9762\u4e2d\u5b9a\u4f4d\u5230\u5bf9\u5e94\u7684\u4e8c\u7ea7\u7d22\u5f15\u8bb0\u5f55\uff0c\u7136\u540e\u56de\u8868\u627e\u5230\u5b83\u5bf9\u5e94\u7684\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\uff0c\u7136\u540e\u518d\u91cd\u590d<code>\u60c5\u666f\u4e00<\/code>\u7684\u505a\u6cd5\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u5373\uff1a\u4e00\u4e2a\u4e8b\u52a1\u5bf9\u65b0\u63d2\u5165\u7684\u8bb0\u5f55\u53ef\u4ee5\u4e0d\u663e\u793a\u7684\u52a0\u9501\uff08\u751f\u6210\u4e00\u4e2a\u9501\u7ed3\u6784\uff09\uff0c\u4f46\u662f\u7531\u4e8e<code>\u4e8b\u52a1id<\/code>\u7684\u5b58\u5728\uff0c\u76f8\u5f53\u4e8e\u52a0\u4e86\u4e00\u4e2a<code>\u9690\u5f0f\u9501<\/code>\u3002\u522b\u7684\u4e8b\u52a1\u5728\u5bf9\u8fd9\u6761\u8bb0\u5f55\u52a0<code>S\u9501<\/code>\u6216\u8005<code>X\u9501<\/code>\u65f6\uff0c\u7531\u4e8e<code>\u9690\u5f0f\u9501<\/code>\u7684\u5b58\u5728\uff0c\u4f1a\u5148\u5e2e\u52a9\u5f53\u524d\u4e8b\u52a1\u751f\u6210\u4e00\u4e2a\u9501\u7ed3\u6784\uff0c\u7136\u540e\u81ea\u5df1\u518d\u751f\u6210\u4e00\u4e2a\u9501\u7ed3\u6784\u540e\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\u3002\u9690\u5f0f\u9501\u662f\u4e00\u79cd<code>\u5ef6\u8fdf\u52a0\u9501<\/code>\u7684\u673a\u5236\uff0c\u4ece\u800c\u6765\u51cf\u5c11\u52a0\u9501\u7684\u6570\u91cf\u3002<\/p>\n\n\n\n<p>\u9690\u5f0f\u9501\u5728\u5b9e\u9645\u5185\u5b58\u5bf9\u8c61\u4e2d\u5e76\u4e0d\u542b\u6709\u8fd9\u4e2a\u9501\u4fe1\u606f\u3002\u53ea\u6709\u5f53\u4ea7\u751f\u9501\u7b49\u5f85\u65f6\uff0c\u9690\u5f0f\u9501\u8f6c\u5316\u4e3a\u663e\u5f0f\u9501\u3002<\/p>\n\n\n\n<p>InnoDB \u7684 insert \u64cd\u4f5c\uff0c\u5bf9\u63d2\u5165\u7684\u8bb0\u5f55\u4e0d\u52a0\u9501\uff0c\u4f46\u662f\u6b64\u65f6\u5982\u679c\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u8fdb\u884c\u5f53\u524d\u8bfb\uff0c\u7c7b\u4f3c\u4ee5\u4e0b\u7684\u7528\u4f8b\uff0csession 2\u4f1a\u9501\u7b49\u5f85 session 1\uff0c\u90a3\u4e48\u8fd9\u662f\u5982\u4f55\u5b9e\u73b0\u7684\u5462\uff1f<\/p>\n\n\n\n<p><strong>session 1\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>begin;\ninsert INTO student VALUES(34,\"\u5468\u516b\",\"\u4e8c\u73ed\");\n<\/code><\/pre>\n\n\n\n<p><strong>session2<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>begin;\nselect * from student lock in share mode; #\u6267\u884c\u5b8c, \u5f53\u524d\u4e8b\u52a1\u88ab\u963b\u585e\n<\/code><\/pre>\n\n\n\n<p>\u6267\u884c\u4e0b\u8ff0\u8bed\u53e5\uff0c\u8f93\u51fa\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># \u53ea\u6267\u884csession1\uff0csession2\u6ca1\u6709\u6267\u884c\u4e4b\u524d\n# session1\u4e2d\u7684\u63d2\u5165\u64cd\u4f5c\uff0c\u53ea\u4f1a\u83b7\u53d6\u5230\u4e00\u4e2a\u8868\u7ea7\u522b\u7684\u610f\u5411\u9501\nSELECT * FROM performance_schema.data_locks\\G\n*************************** 1. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109606808:1098:139647036500528\nENGINE_TRANSACTION_ID: 122410\n            THREAD_ID: 96\n             EVENT_ID: 13\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: NULL\nOBJECT_INSTANCE_BEGIN: 139647036500528\n            LOCK_TYPE: TABLE\n            LOCK_MODE: IX\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: NULL\n# \u6267\u884csession1\u540e\u6267\u884csession2\n# session1\u4e2d\u7684\u63d2\u5165\u64cd\u4f5c\uff0c\u4f1a\u83b7\u53d6\u5230\u4e00\u4e2a\u8868\u7ea7\u522b\u7684\u610f\u5411\u9501\u548c\u4e00\u4e2a\u8bb0\u5f55\u9501\n# \u8bf4\u660e\u9690\u5f0f\u9501\u53d8\u6210\u4e86\u771f\u5b9e\u5b58\u5728\u7684\u8bb0\u5f55\u9501\nSELECT * FROM performance_schema.data_locks\\G\n*************************** 1. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109606808:1098:139647036500528\nENGINE_TRANSACTION_ID: 122410\n            THREAD_ID: 96\n             EVENT_ID: 13\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: NULL\nOBJECT_INSTANCE_BEGIN: 139647036500528\n            LOCK_TYPE: TABLE\n            LOCK_MODE: IX\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: NULL\n*************************** 2. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109606808:39:4:10:139647036497536\nENGINE_TRANSACTION_ID: 122410\n            THREAD_ID: 97\n             EVENT_ID: 13\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 139647036497536\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,REC_NOT_GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 34\n<\/code><\/pre>\n\n\n\n<p>\u9690\u5f0f\u9501\u7684\u903b\u8f91\u8fc7\u7a0b\u5982\u4e0b:<\/p>\n\n\n\n<p>A. InnoDB\u7684\u6bcf\u6761\u8bb0\u5f55\u4e2d\u90fd\u542b\u6709\u4e00\u4e2a\u9690\u542b\u7684trx_id\u5b57\u6bb5\uff0c\u8fd9\u4e2a\u5b57\u6bb5\u5b58\u5728\u4e8e\u805a\u7c07\u7d22\u5f15\u7684B+Tree\u4e2d\u3002<\/p>\n\n\n\n<p>B. \u5728\u64cd\u4f5c\u4e00\u6761\u8bb0\u5f55\u524d\uff0c\u9996\u5148\u6839\u636e\u8bb0\u5f55\u4e2d\u7684trx_id\u68c0\u67e5\u8be5\u4e8b\u52a1\u662f\u5426\u662f\u6d3b\u52a8\u7684\u4e8b\u52a1(\u672a\u63d0\u4ea4\u6216\u56de\u6eda)\u3002\u5982\u679c\u662f\u6d3b\u52a8\u7684\u4e8b\u52a1\uff0c\u9996\u5148\u5c06<code>\u9690\u5f0f\u9501<\/code>\u8f6c\u6362\u4e3a<code>\u663e\u5f0f\u9501<\/code>(\u5c31\u662f\u4e3a\u8be5\u4e8b\u52a1\u6dfb\u52a0\u4e00\u4e2a\u9501)\u3002<\/p>\n\n\n\n<p>C. \u68c0\u67e5\u662f\u5426\u6709\u9501\u51b2\u7a81\uff0c\u5982\u679c\u6709\u51b2\u7a81\uff0c\u521b\u5efa\u9501\uff0c\u5e76\u8bbe\u7f6ewaiting\u72b6\u6001\u3002\u5982\u679c\u6ca1\u6709\u51b2\u7a81\u4e0d\u52a0\u9501\uff0c\u8df3\u5230E\u3002<\/p>\n\n\n\n<p>D. \u7b49\u5f85\u52a0\u9501\u6210\u529f\uff0c\u88ab\u5524\u9192\uff0c\u6216\u8005\u8d85\u65f6\u3002<\/p>\n\n\n\n<p>E. \u5199\u6570\u636e\uff0c\u5e76\u5c06\u81ea\u5df1\u7684trx_id\u5199\u5165trx_id\u5b57\u6bb5\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"2\u663e\u5f0f\u9501\">2\uff09\u663e\u5f0f\u9501<\/h4>\n\n\n\n<p>\u901a\u8fc7\u7279\u5b9a\u7684\u8bed\u53e5\u8fdb\u884c\u52a0\u9501\uff0c\u6211\u4eec\u4e00\u822c\u79f0\u4e4b\u4e3a\u663e\u793a\u52a0\u9501\u3002\u4f8b\u5982\uff1a<\/p>\n\n\n\n<p>\u663e\u793a\u52a0\u5171\u4eab\u9501\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select .... lock in share mode\n<\/code><\/pre>\n\n\n\n<p>\u663e\u793a\u52a0\u6392\u5b83\u9501\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select .... for update\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"35-\u5176\u5b83\u9501\u4e4b\u5168\u5c40\u9501\">3.5 \u5176\u5b83\u9501\u4e4b\uff1a\u5168\u5c40\u9501<\/h3>\n\n\n\n<p>\u5168\u5c40\u9501\u5c31\u662f\u5bf9<code>\u6574\u4e2a\u6570\u636e\u5e93\u5b9e\u4f8b<\/code>\u52a0\u9501\u3002\u5f53\u4f60\u9700\u8981\u8ba9\u6574\u4e2a\u5e93\u5904\u4e8e<code>\u53ea\u8bfb\u72b6\u6001<\/code>\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u547d\u4ee4\uff0c\u4e4b\u540e\u5176\u4ed6\u7ebf\u7a0b\u7684\u4ee5\u4e0b\u8bed\u53e5\u4f1a\u88ab\u963b\u585e\uff1a\u6570\u636e\u66f4\u65b0\u8bed\u53e5\uff08\u6570\u636e\u7684\u589e\u5220\u6539\uff09\u3001\u6570\u636e\u5b9a\u4e49\u8bed\u53e5\uff08\u5305\u62ec\u5efa\u8868\u3001\u4fee\u6539\u8868\u7ed3\u6784\u7b49\uff09\u548c\u66f4\u65b0\u7c7b\u4e8b\u52a1\u7684\u63d0\u4ea4\u8bed\u53e5\u3002\u5168\u5c40\u9501\u7684\u5178\u578b\u4f7f\u7528<code>\u573a\u666f<\/code>\u662f\uff1a\u505a<code>\u5168\u5e93\u903b\u8f91\u5907\u4efd<\/code>\u3002<\/p>\n\n\n\n<p>\u5168\u5c40\u9501\u7684\u547d\u4ee4\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Flush tables with read lock\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"36-\u5176\u5b83\u9501\u4e4b\u6b7b\u9501\">3.6 \u5176\u5b83\u9501\u4e4b\uff1a\u6b7b\u9501<\/h3>\n\n\n\n<p>\u6b7b\u9501\u662f\u6307\u4e24\u4e2a\u6216\u591a\u4e2a\u4e8b\u52a1\u5728\u540c\u4e00\u8d44\u6e90\u4e0a\u76f8\u4e92\u5360\u7528\uff0c\u5e76\u8bf7\u6c42\u9501\u5b9a\u5bf9\u65b9\u5360\u7528\u7684\u8d44\u6e90\uff0c\u4ece\u800c\u5bfc\u81f4\u6076\u6027\u5faa\u73af\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"1\u6982\u5ff5\">1\uff09\u6982\u5ff5<\/h4>\n\n\n\n<p>\u4e24\u4e2a\u4e8b\u52a1\u90fd\u6301\u6709\u5bf9\u65b9\u9700\u8981\u7684\u9501\uff0c\u5e76\u4e14\u5728\u7b49\u5f85\u5bf9\u65b9\u91ca\u653e\u9501\uff0c\u5e76\u4e14\u53cc\u65b9\u90fd\u4e0d\u4f1a\u91ca\u653e\u81ea\u5df1\u7684\u9501\u3002<\/p>\n\n\n\n<p><strong>\u4e3e\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><\/th><th>\u4e8b\u52a11<\/th><th>\u4e8b\u52a12<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>start transaction;<br>update account set money=100 where id=1;<\/td><td>start transaction;<\/td><\/tr><tr><td>2<\/td><td><\/td><td>update account set money=100 where id=2;<\/td><\/tr><tr><td>3<\/td><td>update account set money=200 where id=2;<\/td><td><\/td><\/tr><tr><td>4<\/td><td><\/td><td>update account set money=200 where id=1;<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"2\u4ea7\u751f\u6b7b\u9501\u7684\u5fc5\u8981\u6761\u4ef6\">2\uff09\u4ea7\u751f\u6b7b\u9501\u7684\u5fc5\u8981\u6761\u4ef6<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e24\u4e2a\u6216\u8005\u4e24\u4e2a\u4ee5\u4e0a\u4e8b\u52a1<\/li>\n\n\n\n<li>\u6bcf\u4e2a\u4e8b\u52a1\u90fd\u5df2\u7ecf\u6301\u6709\u9501\u5e76\u4e14\u7533\u8bf7\u65b0\u7684\u9501<\/li>\n\n\n\n<li>\u9501\u8d44\u6e90\u540c\u65f6\u53ea\u80fd\u88ab\u540c\u4e00\u4e2a\u4e8b\u52a1\u6301\u6709\u6216\u8005\u4e0d\u517c\u5bb9<\/li>\n\n\n\n<li>\u4e8b\u52a1\u4e4b\u95f4\u56e0\u4e3a\u6301\u6709\u9501\u548c\u7533\u8bf7\u9501\u5bfc\u81f4\u5f7c\u6b64\u5faa\u73af\u7b49\u5f85<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u6b7b\u9501\u7684\u5173\u952e\u5728\u4e8e\uff1a\u4e24\u4e2a(\u6216\u4ee5\u4e0a)\u7684Session\u52a0\u9501\u7684\u987a\u5e8f\u4e0d\u4e00\u81f4\u3002<\/p>\n<\/blockquote>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"3\u5982\u4f55\u5904\u7406\u6b7b\u9501\">3\uff09\u5982\u4f55\u5904\u7406\u6b7b\u9501<\/h4>\n\n\n\n<p>**\u65b9\u5f0f1\uff1a**\u7b49\u5f85\uff0c\u76f4\u5230\u8d85\u65f6\uff08innodb_lock_wait_timeout=50s\uff09<\/p>\n\n\n\n<p>\u5373\u5f53\u4e24\u4e2a\u4e8b\u52a1\u4e92\u76f8\u7b49\u5f85\u65f6\uff0c\u5f53\u4e00\u4e2a\u4e8b\u52a1\u7b49\u5f85\u65f6\u95f4\u8d85\u8fc7\u8bbe\u7f6e\u7684\u9608\u503c\u65f6\uff0c\u5c31\u5c06\u5176<code>\u56de\u6eda<\/code>\uff0c\u53e6\u5916\u4e8b\u52a1\u7ee7\u7eed\u8fdb\u884c\u3002\u8fd9\u79cd\u65b9\u6cd5\u7b80\u5355\u6709\u6548\uff0c\u5728innodb\u4e2d\uff0c\u53c2\u6570<code>innodb_lock_wait_timeout<\/code>\u7528\u6765\u8bbe\u7f6e\u8d85\u65f6\u65f6\u95f4\u3002<\/p>\n\n\n\n<p>\u7f3a\u70b9: \u5bf9\u4e8e\u5728\u7ebf\u670d\u52a1\u6765\u8bf4\uff0c\u8fd9\u4e2a\u7b49\u5f85\u65f6\u95f4\u5f80\u5f80\u662f\u65e0\u6cd5\u63a5\u53d7\u7684\u3002<\/p>\n\n\n\n<p>\u90a3\u5c06\u6b64\u503c\u4fee\u6539\u77ed\u4e00\u4e9b\uff0c\u6bd4\u59821s\uff0c0.1s\u662f\u5426\u5408\u9002\uff1f\u4e0d\u5408\u9002\uff0c\u5bb9\u6613\u8bef\u4f24\u5230\u666e\u901a\u7684\u9501\u7b49\u5f85\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>show variables like 'innodb_lock_wait_timeout';\n+--------------------------+-------+\n| Variable_name            | Value |\n+--------------------------+-------+\n| innodb_lock_wait_timeout | 50    |\n+--------------------------+-------+\n<\/code><\/pre>\n\n\n\n<p>**\u65b9\u5f0f2\uff1a**\u4f7f\u7528\u6b7b\u9501\u68c0\u6d4b\u8fdb\u884c\u6b7b\u9501\u5904\u7406<\/p>\n\n\n\n<p>\u65b9\u5f0f1\u68c0\u6d4b\u6b7b\u9501\u592a\u8fc7\u88ab\u52a8\uff0cinnodb\u8fd8\u63d0\u4f9b\u4e86<code>wait-for graph\u7b97\u6cd5<\/code>\u6765\u4e3b\u52a8\u8fdb\u884c\u6b7b\u9501\u68c0\u6d4b\uff0c\u6bcf\u5f53\u52a0\u9501\u8bf7\u6c42\u65e0\u6cd5\u7acb\u5373\u6ee1\u8db3\u9700\u8981\u5e76\u8fdb\u5165\u7b49\u5f85\u65f6\uff0cwait-for graph \u7b97\u6cd5\u90fd\u4f1a\u88ab\u89e6\u53d1\u3002<\/p>\n\n\n\n<p>\u8fd9\u662f\u4e00\u79cd\u8f83\u4e3a<code>\u4e3b\u52a8\u7684\u6b7b\u9501\u68c0\u6d4b\u673a\u5236<\/code>\uff0c\u8981\u6c42\u6570\u636e\u5e93\u4fdd\u5b58<code>\u9501\u7684\u4fe1\u606f\u94fe\u8868<\/code>\u548c<code>\u4e8b\u52a1\u7b49\u5f85\u94fe\u8868<\/code>\u4e24\u90e8\u5206\u4fe1\u606f\u3002<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"463\" width=\"805\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/09d3cf9bc6974f3a8059691251f11b2c.png\" alt=\"\"><\/p>\n\n\n\n<p>\u57fa\u4e8e\u8fd9\u4e24\u4e2a\u4fe1\u606f\uff0c\u53ef\u4ee5\u7ed8\u5236wait-for graph\uff08\u7b49\u5f85\u56fe\uff09<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"403\" width=\"515\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/770ac35459c748f0bea818257e67a8e0.png\" alt=\"\"><\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u6b7b\u9501\u68c0\u6d4b\u7684\u539f\u7406\u662f\u6784\u5efa\u4e00\u4e2a\u4ee5\u4e8b\u52a1\u4e3a\u9876\u70b9\u3001\u9501\u4e3a\u8fb9\u7684\u6709\u5411\u56fe\uff0c\u5224\u65ad\u6709\u5411\u56fe\u662f\u5426\u5b58\u5728\u73af\uff0c\u5b58\u5728\u5373\u6709\u6b7b\u9501\u3002<\/p>\n<\/blockquote>\n\n\n\n<p>\u4e00\u65e6\u68c0\u6d4b\u5230\u56de\u8def\uff0c\u6709\u6b7b\u9501\uff0c\u8fd9\u65f6\u5019InnoDB\u5b58\u50a8\u5f15\u64ce\u4f1a\u9009\u62e9<strong>\u56de\u6edaundo\u91cf\u6700\u5c0f\u7684\u4e8b\u52a1<\/strong>\uff0c\u8ba9\u5176\u4ed6\u4e8b\u52a1\u7ee7\u7eed\u6267\u884c\uff08<code>innodb_deadlock_detect=on<\/code>&nbsp;\u8868\u793a\u5f00\u542f\u8fd9\u4e2a\u903b\u8f91\uff09\u3002<\/p>\n\n\n\n<p>\u7f3a\u70b9\uff1a\u6bcf\u4e2a\u65b0\u7684\u88ab\u963b\u585e\u7684\u7ebf\u7a0b\uff0c\u90fd\u8981\u5224\u65ad\u662f\u4e0d\u662f\u7531\u4e8e\u81ea\u5df1\u52a0\u5165\u5bfc\u81f4\u4e86\u6b7b\u9501\uff0c\u8fd9\u4e2a\u64cd\u4f5c\u65f6\u95f4\u590d\u6742\u5ea6\u662f O(n)\u3002\u5982\u679c 100\u4e2a\u5e76\u53d1\u7ebf\u7a0b\u540c\u65f6\u66f4\u65b0\u540c\u4e00\u884c\uff0c\u610f\u5473\u7740\u8981\u68c0\u6d4b 100 * 100 = 1 \u4e07\u6b21\uff0c1 \u4e07\u4e2a\u7ebf\u7a0b\u5c31\u4f1a\u6709 1 \u5343\u4e07\u6b21\u68c0\u6d4b\u3002<\/p>\n\n\n\n<p><strong>\u5982\u4f55\u89e3\u51b3<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u65b9\u5f0f1\uff1a\u5173\u95ed\u6b7b\u9501\u68c0\u6d4b\uff0c\u4f46\u610f\u5473\u7740\u53ef\u80fd\u4f1a\u51fa\u73b0\u5927\u91cf\u7684\u8d85\u65f6\uff0c\u4f1a\u5bfc\u81f4\u4e1a\u52a1\u6709\u635f\u3002<\/li>\n\n\n\n<li>\u65b9\u5f0f2\uff1a\u63a7\u5236\u5e76\u53d1\u8bbf\u95ee\u7684\u6570\u91cf\u3002\u6bd4\u5982\u5728\u4e2d\u95f4\u4ef6\u4e2d\u5b9e\u73b0\u5bf9\u4e8e\u76f8\u540c\u884c\u7684\u66f4\u65b0\uff0c\u5728\u8fdb\u5165\u5f15\u64ce\u4e4b\u524d\u6392\u961f\uff0c\u8fd9\u6837\u5728InnoDB\u5185\u90e8\u5c31\u4e0d\u4f1a\u6709\u5927\u91cf\u7684\u6b7b\u9501\u68c0\u6d4b\u5de5\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n<p><strong>\u8fdb\u4e00\u6b65\u7684\u601d\u8def\uff1a<\/strong><\/p>\n\n\n\n<p>\u53ef\u4ee5\u8003\u8651\u901a\u8fc7\u5c06\u4e00\u884c\u6539\u6210\u903b\u8f91\u4e0a\u7684\u591a\u884c\u6765\u51cf\u5c11<code>\u9501\u51b2\u7a81<\/code>\u3002\u6bd4\u5982\uff0c\u8fde\u9501\u8d85\u5e02\u8d26\u6237\u603b\u989d\u7684\u8bb0\u5f55\uff0c\u53ef\u4ee5\u8003\u8651\u653e\u5230\u591a\u6761\u8bb0\u5f55\u4e0a\u3002\u8d26\u6237\u603b\u989d\u7b49\u4e8e\u8fd9\u591a\u6761\u8bb0\u5f55\u7684\u503c\u7684\u603b\u548c\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"4\u5982\u4f55\u907f\u514d\u6b7b\u9501\">4\uff09\u5982\u4f55\u907f\u514d\u6b7b\u9501<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5408\u7406\u8bbe\u8ba1\u7d22\u5f15\uff0c\u4f7f\u4e1a\u52a1 SQL \u5c3d\u53ef\u80fd\u901a\u8fc7\u7d22\u5f15\u5b9a\u4f4d\u66f4\u5c11\u7684\u884c\uff0c\u51cf\u5c11\u9501\u7ade\u4e89\u3002<\/li>\n\n\n\n<li>\u8c03\u6574\u4e1a\u52a1\u903b\u8f91 SQL \u6267\u884c\u987a\u5e8f\uff0c\u907f\u514d update\/delete \u957f\u65f6\u95f4\u6301\u6709\u9501\u7684 SQL \u5728\u4e8b\u52a1\u524d\u9762\u3002<\/li>\n\n\n\n<li>\u907f\u514d\u5927\u4e8b\u52a1\uff0c\u5c3d\u91cf\u5c06\u5927\u4e8b\u52a1\u62c6\u6210\u591a\u4e2a\u5c0f\u4e8b\u52a1\u6765\u5904\u7406\uff0c\u5c0f\u4e8b\u52a1\u7f29\u77ed\u9501\u5b9a\u8d44\u6e90\u7684\u65f6\u95f4\uff0c\u53d1\u751f\u9501\u51b2\u7a81\u7684\u51e0\u7387\u4e5f\u66f4\u5c0f\u3002<\/li>\n\n\n\n<li>\u5728\u5e76\u53d1\u6bd4\u8f83\u9ad8\u7684\u7cfb\u7edf\u4e2d\uff0c\u4e0d\u8981\u663e\u5f0f\u52a0\u9501\uff0c\u7279\u522b\u662f\u5728\u4e8b\u52a1\u91cc\u663e\u5f0f\u52a0\u9501\u3002\u5982 select ... for update \u8bed\u53e5\uff0c\u5982\u679c\u662f\u5728\u4e8b\u52a1\u91cc\u8fd0\u884c\u4e86 start transaction \u6216\u8bbe\u7f6e\u4e86 autocommit \u7b49\u4e8e0\uff0c\u90a3\u4e48\u5c31\u4f1a\u9501\u5b9a\u6240\u67e5\u627e\u5230\u7684\u8bb0\u5f55\u3002<\/li>\n\n\n\n<li>\u964d\u4f4e\u9694\u79bb\u7ea7\u522b\u3002\u5982\u679c\u4e1a\u52a1\u5141\u8bb8\uff0c\u5c06\u9694\u79bb\u7ea7\u522b\u8c03\u4f4e\u4e5f\u662f\u5f88\u597d\u7684\u9009\u62e9\uff0c\u6bd4\u5982\u5c06\u9694\u79bb\u7ea7\u522b\u4ece RR \u8c03\u6574\u4e3a RC\uff0c\u53ef\u4ee5\u907f\u514d\u6389\u5f88\u591a\u56e0\u4e3a gap \u9501\u9020\u6210\u7684\u6b7b\u9501\u3002<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"4-\u9501\u7684\u5185\u5b58\u7ed3\u6784\">4. \u9501\u7684\u5185\u5b58\u7ed3\u6784<\/h2>\n\n\n\n<p>\u5bf9\u4e00\u6761\u8bb0\u5f55\u52a0\u9501\u7684\u672c\u8d28\u5c31\u662f\u5728\u5185\u5b58\u4e2d\u521b\u5efa\u4e00\u4e2a<code>\u9501\u7ed3\u6784<\/code>\u4e0e\u4e4b\u5173\u8054\uff0c\u90a3\u4e48\u662f\u4e0d\u662f\u4e00\u4e2a\u4e8b\u52a1\u5bf9\u591a\u6761\u8bb0\u5f55\u52a0\u9501\uff0c\u5c31\u8981\u521b\u5efa\u591a\u4e2a\u9501\u7ed3\u6784\u5462\uff1f\u6bd4\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># \u4e8b\u52a1T1\nSELECT * FROM user LOCK IN SHARE MODE;\n<\/code><\/pre>\n\n\n\n<p>\u7406\u8bba\u4e0a\u521b\u5efa\u591a\u4e2a\u9501\u7ed3\u6784\u6ca1\u95ee\u9898\uff0c\u4f46\u662f\u5982\u679c\u4e00\u4e2a\u4e8b\u52a1\u8981\u83b7\u53d610000\u6761\u8bb0\u5f55\u7684\u9501\uff0c\u751f\u621010000\u4e2a\u9501\u7ed3\u6784\u4e5f\u592a\u5d29\u6e83\u4e86\uff01<\/p>\n\n\n\n<p>\u6240\u4ee5\u51b3\u5b9a\u5bf9\u4e0d\u540c\u8bb0\u5f55\u52a0\u9501\u65f6\uff0c\u7b26\u5408\u4e0b\u8fb9\u8fd9\u4e9b\u6761\u4ef6\u7684\u8bb0\u5f55\u4f1a\u653e\u5230\u4e00\u4e2a\u9501\u7ed3\u6784\u4e2d\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5728\u540c\u4e00\u4e2a\u4e8b\u52a1\u4e2d\u8fdb\u884c\u52a0\u9501\u64cd\u4f5c<\/li>\n\n\n\n<li>\u88ab\u52a0\u9501\u7684\u8bb0\u5f55\u5728\u540c\u4e00\u4e2a\u9875\u9762\u4e2d<\/li>\n\n\n\n<li>\u52a0\u9501\u7684\u7c7b\u578b\u662f\u4e00\u6837\u7684<\/li>\n\n\n\n<li>\u7b49\u5f85\u72b6\u6001\u662f\u4e00\u6837\u7684<\/li>\n<\/ul>\n\n\n\n<p><strong>InnoDB\u5b58\u50a8\u5f15\u64ce\u4e2d\u7684\u9501\u7ed3\u6784\u5982\u4e0b\uff1a<\/strong><\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"778\" width=\"1104\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/40cc302da82d4a4f85420fda2f39bdd8.png\" alt=\"\"><\/p>\n\n\n\n<p>\u7ed3\u6784\u89e3\u6790\uff1a<\/p>\n\n\n\n<p><strong>1\uff09\u9501\u6240\u5728\u7684\u4e8b\u52a1\u4fe1\u606f\uff1a<\/strong><\/p>\n\n\n\n<p>\u4e0d\u8bba\u662f<code>\u8868\u9501<\/code>\u8fd8\u662f<code>\u884c\u9501<\/code>\uff0c\u90fd\u662f\u5728\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u751f\u6210\u7684\uff0c\u54ea\u4e2a\u4e8b\u52a1\u751f\u6210\u4e86\u8fd9\u4e2a\u9501\u7ed3\u6784\uff0c\u8fd9\u91cc\u5c31\u8bb0\u5f55\u8fd9\u4e2a\u4e8b\u52a1\u7684\u4fe1\u606f\u3002<\/p>\n\n\n\n<p>\u6b64<code>\u9501\u6240\u5728\u7684\u4e8b\u52a1\u4fe1\u606f<\/code>\u5728\u5185\u5b58\u7ed3\u6784\u4e2d\u53ea\u662f\u4e00\u4e2a\u6307\u9488\uff0c\u901a\u8fc7\u6307\u9488\u53ef\u4ee5\u627e\u5230\u5185\u5b58\u4e2d\u5173\u4e8e\u8be5\u4e8b\u52a1\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u6bd4\u65b9\u8bf4\u4e8b\u52a1id\u7b49\u3002<\/p>\n\n\n\n<p><strong>2\uff09\u7d22\u5f15\u4fe1\u606f<\/strong><\/p>\n\n\n\n<p>\u5bf9\u4e8e<code>\u884c\u9501<\/code>\u6765\u8bf4\uff0c\u9700\u8981\u8bb0\u5f55\u4e00\u4e0b\u52a0\u9501\u7684\u8bb0\u5f55\u662f\u5c5e\u4e8e\u54ea\u4e2a\u7d22\u5f15\u7684\u3002\u8fd9\u91cc\u4e5f\u662f\u4e00\u4e2a\u6307\u9488\u3002<\/p>\n\n\n\n<p><strong>3\uff09\u8868\u9501\uff0f\u884c\u9501\u4fe1\u606f<\/strong><\/p>\n\n\n\n<p><code>\u8868\u9501\u7ed3\u6784<\/code>\u548c<code>\u884c\u9501\u7ed3\u6784<\/code>\u5728\u8fd9\u4e2a\u4f4d\u7f6e\u7684\u5185\u5bb9\u662f\u4e0d\u540c\u7684\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8868\u9501\uff1a\u8bb0\u8f7d\u7740\u662f\u5bf9\u54ea\u4e2a\u8868\u52a0\u7684\u9501\uff0c\u8fd8\u6709\u5176\u4ed6\u7684\u4e00\u4e9b\u4fe1\u606f\u3002<\/li>\n\n\n\n<li>\u884c\u9501\uff1a\u8bb0\u8f7d\u4e86\u4e09\u4e2a\u91cd\u8981\u7684\u4fe1\u606f\uff1a\n<ul class=\"wp-block-list\">\n<li><code>Space ID<\/code>\u00a0\uff1a\u8bb0\u5f55\u6240\u5728\u8868\u7a7a\u95f4\u3002<\/li>\n\n\n\n<li><code>Page Number<\/code>\u00a0\uff1a\u8bb0\u5f55\u6240\u5728\u9875\u53f7\u3002<\/li>\n\n\n\n<li><code>n_bits<\/code>\u00a0\uff1a\u5bf9\u4e8e\u884c\u9501\u6765\u8bf4\uff0c\u4e00\u6761\u8bb0\u5f55\u5c31\u5bf9\u5e94\u7740\u4e00\u4e2a\u6bd4\u7279\u4f4d\uff0c\u4e00\u4e2a\u9875\u9762\u4e2d\u5305\u542b\u5f88\u591a\u8bb0\u5f55\uff0c\u7528\u4e0d\u540c\u7684\u6bd4\u7279\u4f4d\u6765\u533a\u5206\u5230\u5e95\u662f\u54ea\u4e00\u6761\u8bb0\u5f55\u52a0\u4e86\u9501\u3002\u4e3a\u6b64\u5728\u884c\u9501\u7ed3\u6784\u7684\u672b\u5c3e\u653e\u7f6e\u4e86\u4e00\u5806\u6bd4\u7279\u4f4d\uff0c\u8fd9\u4e2a<code>n_bits<\/code>\u5c5e\u6027\u4ee3\u8868\u4f7f\u7528\u4e86\u591a\u5c11\u6bd4\u7279\u4f4d\u3002 n_bits\u7684\u503c\u4e00\u822c\u90fd\u6bd4\u9875\u9762\u4e2d\u8bb0\u5f55\u6761\u6570\u591a\u4e00\u4e9b\u3002\u4e3b\u8981\u662f\u4e3a\u4e86\u4e4b\u540e\u5728\u9875\u9762\u4e2d\u63d2\u5165\u4e86\u65b0\u8bb0\u5f55\u540e\u4e5f\u4e0d\u81f3\u4e8e\u91cd\u65b0\u5206\u914d\u9501\u7ed3\u6784<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p><strong>4\uff09type_mode<\/strong><\/p>\n\n\n\n<p>\u8fd9\u662f\u4e00\u4e2a32\u4f4d\u7684\u6570\uff0c\u88ab\u5206\u6210\u4e86<code>lock_mode<\/code>\u3001<code>lock_type<\/code>\u548c<code>rec_lock_type<\/code>\u4e09\u4e2a\u90e8\u5206\uff0c\u5982\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"352\" width=\"1115\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/d2c620c056904f16ba0c27003e398601.png\" alt=\"\"><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9501\u7684\u6a21\u5f0f\uff08<code>lock_mode<\/code>\uff09\uff0c\u5360\u7528\u4f4e4\u4f4d\uff0c\u53ef\u9009\u7684\u503c\u5982\u4e0b\uff1a\n<ul class=\"wp-block-list\">\n<li><code>LOCK_IS<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>0<\/code>\uff09\uff1a\u8868\u793a\u5171\u4eab\u610f\u5411\u9501\uff0c\u4e5f\u5c31\u662f<code>IS\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_IX<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>1<\/code>\uff09\uff1a\u8868\u793a\u72ec\u5360\u610f\u5411\u9501\uff0c\u4e5f\u5c31\u662f<code>IX\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_S<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>2<\/code>\uff09\uff1a\u8868\u793a\u5171\u4eab\u9501\uff0c\u4e5f\u5c31\u662f<code>S\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_X<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>3<\/code>\uff09\uff1a\u8868\u793a\u72ec\u5360\u9501\uff0c\u4e5f\u5c31\u662f<code>X\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_AUTO_INC<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>4<\/code>\uff09\uff1a\u8868\u793a<code>AUTO-INC\u9501<\/code>\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u5728InnoDB\u5b58\u50a8\u5f15\u64ce\u4e2d\uff0cLOCK_IS\uff0cLOCK_IX\uff0cLOCK_AUTO_INC\u90fd\u7b97\u662f\u8868\u7ea7\u9501\u7684\u6a21\u5f0f\uff0cLOCK_S\u548c LOCK_X\u65e2\u53ef\u4ee5\u7b97\u662f\u8868\u7ea7\u9501\u7684\u6a21\u5f0f\uff0c\u4e5f\u53ef\u4ee5\u662f\u884c\u7ea7\u9501\u7684\u6a21\u5f0f\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9501\u7684\u7c7b\u578b\uff08<code>lock_type<\/code>\uff09\uff0c\u5360\u7528\u7b2c5\uff5e8\u4f4d\uff0c\u4e0d\u8fc7\u73b0\u9636\u6bb5\u53ea\u6709\u7b2c5\u4f4d\u548c\u7b2c6\u4f4d\u88ab\u4f7f\u7528\uff1a\n<ul class=\"wp-block-list\">\n<li><code>LOCK_TABLE<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>16<\/code>\uff09\uff0c\u4e5f\u5c31\u662f\u5f53\u7b2c5\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u8868\u7ea7\u9501\u3002<\/li>\n\n\n\n<li><code>LOCK_REC<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>32<\/code>\uff09\uff0c\u4e5f\u5c31\u662f\u5f53\u7b2c6\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u884c\u7ea7\u9501\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u884c\u9501\u7684\u5177\u4f53\u7c7b\u578b\uff08<code>rec_lock_type<\/code>\uff09\uff0c\u4f7f\u7528\u5176\u4f59\u7684\u4f4d\u6765\u8868\u793a\u3002\u53ea\u6709\u5728\u00a0<code>lock_type<\/code>\u7684\u503c\u4e3a<code>LOCK_REC<\/code>\u65f6\uff0c\u4e5f\u5c31\u662f\u53ea\u6709\u5728\u8be5\u9501\u4e3a\u884c\u7ea7\u9501\u65f6\uff0c\u624d\u4f1a\u88ab\u7ec6\u5206\u4e3a\u66f4\u591a\u7684\u7c7b\u578b\uff1a\n<ul class=\"wp-block-list\">\n<li><code>LOCK_ORDINARY<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>0<\/code>\uff09\uff1a\u8868\u793a<code>next-key\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_GAP<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>512<\/code>\uff09\uff1a\u4e5f\u5c31\u662f\u5f53\u7b2c10\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a<code>gap\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_REC_NOT_GAP<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>1024<\/code>\uff09\uff1a\u4e5f\u5c31\u662f\u5f53\u7b2c11\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u6b63\u7ecf<code>\u8bb0\u5f55\u9501<\/code>\u3002<\/li>\n\n\n\n<li><code>LOCK_INSERT_INTENTION<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>2048<\/code>\uff09\uff1a\u4e5f\u5c31\u662f\u5f53\u7b2c12\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a1\u65f6\uff0c\u8868\u793a\u63d2\u5165\u610f\u5411\u9501\u3002\u5176\u4ed6\u7684\u7c7b\u578b\uff1a\u8fd8\u6709\u4e00\u4e9b\u4e0d\u5e38\u7528\u7684\u7c7b\u578b\u6211\u4eec\u5c31\u4e0d\u591a\u8bf4\u4e86\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><code>is_waiting<\/code>\u5c5e\u6027\u5462\uff1f\u57fa\u4e8e\u5185\u5b58\u7a7a\u95f4\u7684\u8282\u7701\uff0c\u6240\u4ee5\u628a<code>is_waiting<\/code>\u5c5e\u6027\u653e\u5230\u4e86<code>type_mode<\/code>\u8fd9\u4e2a32\u4f4d\u7684\u6570\u5b57\u4e2d\uff1a\n<ul class=\"wp-block-list\">\n<li><code>LOCK_WAIT<\/code>\uff08\u5341\u8fdb\u5236\u7684<code>256<\/code>\uff09 \uff1a\u5f53\u7b2c9\u4e2a\u6bd4\u7279\u4f4d\u7f6e\u4e3a<code>1<\/code>\u65f6\uff0c\u8868\u793a<code>is_waiting<\/code>\u4e3a<code>true<\/code>\uff0c\u4e5f\u5c31\u662f\u5f53\u524d\u4e8b\u52a1\u5c1a\u672a\u83b7\u53d6\u5230\u9501\uff0c\u5904\u5728\u7b49\u5f85\u72b6\u6001\uff1b\u5f53\u8fd9\u4e2a\u6bd4\u7279\u4f4d\u4e3a<code>0<\/code>\u65f6\uff0c\u8868\u793a<code>is_waiting<\/code>\u4e3a<code>false<\/code>\uff0c\u4e5f\u5c31\u662f\u5f53\u524d\u4e8b\u52a1\u83b7\u53d6\u9501\u6210\u529f\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p><strong>5\uff09\u5176\u4ed6\u4fe1\u606f<\/strong><\/p>\n\n\n\n<p>\u4e3a\u4e86\u66f4\u597d\u7684\u7ba1\u7406\u7cfb\u7edf\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u751f\u6210\u7684\u5404\u79cd\u9501\u7ed3\u6784\u800c\u8bbe\u8ba1\u4e86\u5404\u79cd\u54c8\u5e0c\u8868\u548c\u94fe\u8868\u3002<\/p>\n\n\n\n<p><strong>6) \u4e00\u5806\u6bd4\u7279\u4f4d<\/strong><\/p>\n\n\n\n<p>\u5982\u679c\u662f<code>\u884c\u9501\u7ed3\u6784<\/code>\u7684\u8bdd\uff0c\u5728\u8be5\u7ed3\u6784\u672b\u5c3e\u8fd8\u653e\u7f6e\u4e86\u4e00\u5806\u6bd4\u7279\u4f4d\uff0c\u6bd4\u7279\u4f4d\u7684\u6570\u91cf\u662f\u7531\u4e0a\u8fb9\u63d0\u5230\u7684<code>n_bits<\/code>\u5c5e\u6027\u8868\u793a\u7684\u3002InnoDB\u6570\u636e\u9875\u4e2d\u7684\u6bcf\u6761\u8bb0\u5f55\u5728<code>\u8bb0\u5f55\u5934\u4fe1\u606f<\/code>\u4e2d\u90fd\u5305\u542b\u4e00\u4e2a<code>heap_no<\/code>\u5c5e\u6027\uff0c\u4f2a\u8bb0\u5f55<code>Infimum<\/code>\u7684<code>heap_no<\/code>\u503c\u4e3a<code>0<\/code>\uff0c<code>Supremum<\/code>\u7684<code>heap_no<\/code>\u503c\u4e3a<code>1<\/code>\uff0c\u4e4b\u540e\u6bcf\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\uff0c<code>heap_no<\/code>\u503c\u5c31\u589e1\u3002<code>\u9501\u7ed3\u6784<\/code>\u6700\u540e\u7684\u4e00\u5806\u6bd4\u7279\u4f4d\u5c31\u5bf9\u5e94\u7740\u4e00\u4e2a\u9875\u9762\u4e2d\u7684\u8bb0\u5f55\uff0c\u4e00\u4e2a\u6bd4\u7279\u4f4d\u6620\u5c04\u4e00\u4e2a<code>heap_no<\/code>\uff0c\u5373\u4e00\u4e2a\u6bd4\u7279\u4f4d\u6620\u5c04\u5230\u9875\u5185\u7684\u4e00\u6761\u8bb0\u5f55\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"5-\u9501\u76d1\u63a7\">5. \u9501\u76d1\u63a7<\/h2>\n\n\n\n<p>\u5173\u4e8eMySQL\u9501\u7684\u76d1\u63a7\uff0c\u6211\u4eec\u4e00\u822c\u53ef\u4ee5\u901a\u8fc7\u68c0\u67e5<code>InnoDB_row_lock<\/code>\u7b49\u72b6\u6001\u53d8\u91cf\u6765\u5206\u6790\u7cfb\u7edf\u4e0a\u7684\u884c\u9501\u7684\u4e89\u593a\u60c5\u51b5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql> show status like 'innodb_row_lock%';\n+-------------------------------+--------+\n| Variable_name                 | Value  |\n+-------------------------------+--------+\n| Innodb_row_lock_current_waits | 0      |\n| Innodb_row_lock_time          | 490002 |\n| Innodb_row_lock_time_avg      | 28823  |\n| Innodb_row_lock_time_max      | 51010  |\n| Innodb_row_lock_waits         | 17     |\n+-------------------------------+--------+<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Innodb_row_lock_current_waits\uff1a\u5f53\u524d\u6b63\u5728\u7b49\u5f85\u9501\u5b9a\u7684\u6570\u91cf\uff1b<\/li>\n\n\n\n<li><code>Innodb_row_lock_time<\/code>\uff1a\u4ece\u7cfb\u7edf\u542f\u52a8\u5230\u73b0\u5728\u9501\u5b9a\u603b\u65f6\u95f4\u957f\u5ea6\uff1b\uff08\u7b49\u5f85\u603b\u65f6\u957f\uff09<\/li>\n\n\n\n<li><code>Innodb_row_lock_time_avg<\/code>\uff1a\u6bcf\u6b21\u7b49\u5f85\u6240\u82b1\u5e73\u5747\u65f6\u95f4\uff1b\uff08\u7b49\u5f85\u5e73\u5747\u65f6\u957f\uff09<\/li>\n\n\n\n<li>Innodb_row_lock_time_max\uff1a\u4ece\u7cfb\u7edf\u542f\u52a8\u5230\u73b0\u5728\u7b49\u5f85\u6700\u5e38\u7684\u4e00\u6b21\u6240\u82b1\u7684\u65f6\u95f4\uff1b<\/li>\n\n\n\n<li><code>Innodb_row_lock_waits<\/code>\uff1a\u7cfb\u7edf\u542f\u52a8\u540e\u5230\u73b0\u5728\u603b\u5171\u7b49\u5f85\u7684\u6b21\u6570\uff1b\uff08\u7b49\u5f85\u603b\u6b21\u6570\uff09<\/li>\n<\/ul>\n\n\n\n<p><strong>\u5176\u4ed6\u76d1\u63a7\u65b9\u6cd5\uff1a<\/strong><\/p>\n\n\n\n<p>MySQL\u628a\u4e8b\u52a1\u548c\u9501\u7684\u4fe1\u606f\u8bb0\u5f55\u5728\u4e86<code>information_schema<\/code>\u5e93\u4e2d\uff0c\u6d89\u53ca\u5230\u7684\u4e09\u5f20\u8868\u5206\u522b\u662f<code>INNODB_TRX<\/code>\u3001<code>INNODB_LOCKS<\/code>\u548c<code>INNODB_LOCK_WAITS<\/code>\u3002<\/p>\n\n\n\n<p><code>MySQL5.7\u53ca\u4e4b\u524d<\/code>\uff0c\u53ef\u4ee5\u901a\u8fc7information_schema.INNODB_LOCKS\u67e5\u770b\u4e8b\u52a1\u7684\u9501\u60c5\u51b5\uff0c\u4f46\u53ea\u80fd\u770b\u5230\u963b\u585e\u4e8b\u52a1\u7684\u9501\uff1b\u5982\u679c\u4e8b\u52a1\u5e76\u672a\u88ab\u963b\u585e\uff0c\u5219\u5728\u8be5\u8868\u4e2d\u770b\u4e0d\u5230\u8be5\u4e8b\u52a1\u7684\u9501\u60c5\u51b5\u3002<\/p>\n\n\n\n<p>MySQL8.0<\/p>\n\n\n\n<p>\u5220\u9664\u4e86information_schema.INNODB_LOCKS\uff0c<\/p>\n\n\n\n<p>\u6dfb\u52a0\u4e86<code>performance_schema.data_locks<\/code>\uff0c\u53ef\u4ee5\u901a\u8fc7performance_schema.data_locks\u67e5\u770b\u4e8b\u52a1\u7684\u9501\u60c5\u51b5\uff0c\u548cMySQL5.7\u53ca\u4e4b\u524d\u4e0d\u540c\uff0cperformance_schema.data_locks\u4e0d\u4f46\u53ef\u4ee5\u770b\u5230\u963b\u585e\u8be5\u4e8b\u52a1\u7684\u9501\uff0c\u8fd8\u53ef\u4ee5\u770b\u5230\u8be5\u4e8b\u52a1\u6240\u6301\u6709\u7684\u9501\u3002<\/p>\n\n\n\n<p>\u540c\u65f6\uff0cinformation_schema.INNODB_LOCK_WAITS\u4e5f\u88ab<code>performance_schema.data_lock_waits<\/code>\u6240\u4ee3\u66ff\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u67e5\u8be2\u6b63\u5728\u88ab\u9501\u963b\u585e\u7684sql\u8bed\u53e5\u3002<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM information_schema.INNODB_TRX\\G<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u67e5\u8be2\u9501\u7b49\u5f85\u60c5\u51b5<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM performance_schema.data_lock_waits\\G\n*************************** 1. row ***************************\n                          ENGINE: INNODB\n       REQUESTING_ENGINE_LOCK_ID: 139647109608520:39:4:2:139647036509792\nREQUESTING_ENGINE_TRANSACTION_ID: 421122086319176\n            REQUESTING_THREAD_ID: 101\n             REQUESTING_EVENT_ID: 12\nREQUESTING_OBJECT_INSTANCE_BEGIN: 139647036509792\n         BLOCKING_ENGINE_LOCK_ID: 139647109607664:39:4:2:139647036503760\n  BLOCKING_ENGINE_TRANSACTION_ID: 122418\n              BLOCKING_THREAD_ID: 100\n               BLOCKING_EVENT_ID: 11\n  BLOCKING_OBJECT_INSTANCE_BEGIN: 139647036503760\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code># \u67e5\u770b\u7ebf\u7a0b\uff0c\u4ee5\u53ca\u7ebf\u7a0b\u7b49\u5f85\u5177\u4f53\u9501\u7684\u72b6\u6001\nSHOW PROCESSLIST;\n<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u67e5\u8be2\u9501\u7684\u60c5\u51b5<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code># mysql8.0\u4ee5\u540e\nSELECT * FROM performance_schema.data_locks\\G\n*************************** 1. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 139647109608520:1098:139647036512704\nENGINE_TRANSACTION_ID: 122419\n            THREAD_ID: 101\n             EVENT_ID: 12\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: student\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: NULL\nOBJECT_INSTANCE_BEGIN: 139647036512704\n            LOCK_TYPE: TABLE\n            LOCK_MODE: IS\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: NULL\n<\/code><\/pre>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>MyISAM \u7684\u8868\u9501\uff0c\u8981\u901a\u8fc7&nbsp;<code>performance_schema.metadata_locks<\/code>&nbsp;\u67e5\u8be2<\/p>\n\n\n\n<p><code>data_locks<\/code>&nbsp;\u67e5\u4e0d\u5230<\/p>\n<\/blockquote>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u67e5MyISAM\u5f15\u64ce\uff0c\u6570\u636e\u8868\u7684\u9501<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM performance_schema.metadata_locks\nWHERE OBJECT_NAME = 'table_name';\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"6-\u589e\u5220\u6539\u67e5\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501innodb\">6. \u589e\u5220\u6539\u67e5\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501\uff08InnoDB\uff09<\/h2>\n\n\n\n<p><a href=\"https:\/\/dev.mysql.com\/doc\/refman\/8.4\/en\/innodb-locks-set.html\" target=\"_blank\"  rel=\"nofollow\" >MySQL 8.4 Reference Manual :: 17.7.3 Locks Set by Different SQL Statements in InnoDB<\/a><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT * FROM performance_schema.data_locks\\G\n*************************** \u9501\u4f4f\u7684\u7d22\u5f15 ***************************\nINDEX_NAME \n*************************** \u9501\u7684\u7c7b\u578b ***************************\nLOCK_MODE: X,REC_NOT_GAP # \u8bb0\u5f55\u9501\nLOCK_MODE: X,GAP         # \u95f4\u9699\u9501\nLOCK_MODE: X             # \u4e34\u952e\u9501\n*************************** \u9501\u4f4f\u7684\u6570\u636e ***************************\nLOCK_DATA: 10, 10 # \u4e8c\u7ea7\u7d22\u5f15\nLOCK_DATA: 10     # \u4e3b\u952e\u7d22\u5f15<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"61-\u901a\u7528\u7684\u52a0\u9501\u89c4\u5219\">6.1 \u901a\u7528\u7684\u52a0\u9501\u89c4\u5219<\/h3>\n\n\n\n<p>\u9501\u5b9a\u8bfb\u53d6\u3001\u66f4\u65b0\u6216\u5220\u9664\u64cd\u4f5c\u4f1a\u5728\u5904\u7406SQL\u8bed\u53e5\u65f6\u5bf9<strong>\u6bcf\u4e2a\u626b\u63cf\u5230\u7684\u7d22\u5f15\u8bb0\u5f55<\/strong>\u8bbe\u7f6e\u9501\u3002\u8fd9\u4e0e\u8bed\u53e5\u4e2d\u662f\u5426\u5305\u542b\u53ef\u4ee5\u6392\u9664\u8be5\u884c\u7684 WHERE \u6761\u4ef6\u65e0\u5173\u3002InnoDB \u4e0d\u8bb0\u5f97\u786e\u5207\u7684 WHERE \u6761\u4ef6\uff0c\u800c\u4ec5\u77e5\u9053\u626b\u63cf\u4e86\u54ea\u4e9b\u7d22\u5f15\u8303\u56f4\u3002<\/p>\n\n\n\n<p>**\u52a0\u9501\u7684\u57fa\u672c\u5355\u4f4d\u662f<code>\u4e34\u952e\u9501<\/code>\u3002<strong>\u963b\u6b62\u5728\u8bb0\u5f55\u524d\u7684\u95f4\u9699\u4e2d\u63d2\u5165\u65b0\u6570\u636e\u3002<\/strong><code>\u4e34\u952e\u9501<\/code>\u662f\u524d\u5f00\u540e\u95ed\u533a\u95f4\u3002**\u6bcf\u4e2a\u88ab\u626b\u63cf\u5230\u7684\u7d22\u5f15\u8bb0\u5f55\uff0c\u662f\u52a0\u9501\u533a\u95f4\u7684\u53f3\u786e\u754c\u3002\u4e0d\u8fc7\uff0c\u53ef\u4ee5\u663e\u5f0f\u7981\u7528\u95f4\u9699\u9501\u5b9a\uff0c\u8fd9\u6837\u5c31\u4e0d\u4f1a\u4f7f\u7528\u4e34\u952e\u9501\u5b9a\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u60f3\u8c61\u4e00\u4e2a\u524d\u5f00\u540e\u95ed\u7684\u533a\u95f4\uff0c\u4e00\u76f4\u5411\u53f3\u6ed1\u52a8\u3002(\u4e0a\u4e00\u6761\u7d22\u5f15\u8bb0\u5f55\uff0c\u5f53\u524d\u7684\u7d22\u5f15\u8bb0\u5f55]<\/p>\n<\/blockquote>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"1\u6ca1\u6709\u4f7f\u7528\u7d22\u5f15\u60c5\u51b5\">1\uff09\u6ca1\u6709\u4f7f\u7528\u7d22\u5f15\u60c5\u51b5<\/h4>\n\n\n\n<p>\u5982\u679cSQL\u8bed\u53e5\u6ca1\u6709\u5408\u9002\u7684\u7d22\u5f15\uff0c\u5bfc\u81f4 MySQL \u5fc5\u987b\u626b\u63cf\u6574\u4e2a\u8868\u4ee5\u5904\u7406\u8be5\u8bed\u53e5\uff0c\u90a3\u4e48\u8868\u7684\u6bcf\u4e00\u884c\u90fd\u4f1a\u88ab\u9501\u5b9a\u3002<\/p>\n\n\n\n<p><strong>\u5982\u4f55\u907f\u514d\u8fd9\u79cd\u4e8b\u6545\u7684\u53d1\u751f\uff1f<\/strong><\/p>\n\n\n\n<p>\u53ef\u4ee5\u5c06 MySQL \u91cc\u7684&nbsp;<code>sql_safe_updates<\/code>&nbsp;\u53c2\u6570\u8bbe\u7f6e\u4e3a 1\uff0c\u5f00\u542f\u5b89\u5168\u66f4\u65b0\u6a21\u5f0f\u3002<\/p>\n\n\n\n<p>update \u8bed\u53e5\u5fc5\u987b\u6ee1\u8db3\u5982\u4e0b\u6761\u4ef6\u4e4b\u4e00\u624d\u80fd\u6267\u884c\u6210\u529f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528 where\uff0c\u5e76\u4e14 where \u6761\u4ef6\u4e2d\u5fc5\u987b\u6709\u7d22\u5f15\u5217\uff1b<\/li>\n\n\n\n<li>\u4f7f\u7528 limit\uff1b<\/li>\n\n\n\n<li>\u540c\u65f6\u4f7f\u7528 where \u548c limit\uff0c\u6b64\u65f6 where \u6761\u4ef6\u4e2d\u53ef\u4ee5\u6ca1\u6709\u7d22\u5f15\u5217\uff1b<\/li>\n<\/ul>\n\n\n\n<p>delete \u8bed\u53e5\u5fc5\u987b\u6ee1\u8db3\u4ee5\u4e0b\u6761\u4ef6\u624d\u80fd\u6267\u884c\u6210\u529f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u540c\u65f6\u4f7f\u7528 where \u548c limit\uff0c\u6b64\u65f6 where \u6761\u4ef6\u4e2d\u53ef\u4ee5\u6ca1\u6709\u7d22\u5f15\u5217\uff1b<\/li>\n<\/ul>\n\n\n\n<p>\u5982\u679c where \u6761\u4ef6\u5e26\u4e0a\u4e86\u7d22\u5f15\u5217\uff0c\u4f46\u662f\u4f18\u5316\u5668\u6700\u7ec8\u626b\u63cf\u9009\u62e9\u7684\u662f\u5168\u8868\uff0c\u800c\u4e0d\u662f\u7d22\u5f15\u7684\u8bdd\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528&nbsp;<code>force index([index_name])<\/code>&nbsp;\u53ef\u4ee5\u544a\u8bc9\u4f18\u5316\u5668\u4f7f\u7528\u54ea\u4e2a\u7d22\u5f15\uff0c\u4ee5\u6b64\u907f\u514d\u6709\u51e0\u7387\u9501\u5168\u8868\u5e26\u6765\u7684\u9690\u60a3\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"2\u552f\u4e00\u7d22\u5f15vs\u975e\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2vs\u8303\u56f4\u67e5\u8be2\">2\uff09\u552f\u4e00\u7d22\u5f15VS\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u7b49\u503c\u67e5\u8be2VS\u8303\u56f4\u67e5\u8be2<\/h4>\n\n\n\n<p>\u9501\u5b9a\u8bfb\u53d6\uff08<code>SELECT ... FOR UPDATE<\/code>&nbsp;\u6216&nbsp;<code>FOR SHARE<\/code>\uff09\u3001<code>UPDATE<\/code>&nbsp;\u548c&nbsp;<code>DELETE<\/code>&nbsp;\u8bed\u53e5\uff0c\u6240\u91c7\u53d6\u7684\u9501\u53d6\u51b3\u4e8ewhere\u5b50\u53e5\u4e2d\u7684\u641c\u7d22\u6761\u4ef6\uff08\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\u6216\u8303\u56f4\u7c7b\u578b\u7684\u641c\u7d22\u6761\u4ef6\uff09<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\u4e2d<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u5f53\u67e5\u8be2\u7684\u8bb0\u5f55\u5b58\u5728\uff0c<code>next-key lock<\/code>\u00a0\u4f1a<strong>\u9000\u5316\u6210\u8bb0\u5f55\u9501<\/strong>\uff0cInnoDB \u53ea\u9501\u5b9a\u627e\u5230\u7684\u7d22\u5f15\u8bb0\u5f55<\/li>\n\n\n\n<li>\u5f53\u67e5\u8be2\u7684\u8bb0\u5f55\u4e0d\u5b58\u5728\uff0c<code>next-key lock<\/code>\u00a0\u4f1a<strong>\u9000\u5316\u6210\u95f4\u9699\u9501<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u975e\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2<\/strong> \u4f1a\u7ed9\u6bcf\u6761\u626b\u63cf\u5230\u7684\u8bb0\u5f55\uff0c\u52a0\u4e0a\u4e34\u952e\u9501<code>\uff08\u4e0a\u4e00\u6761\u8bb0\u5f55\uff0c\u5f53\u524d\u626b\u63cf\u5230\u7684\u8bb0\u5f55]<\/code>\u3002\u4e00\u76f4\u5411\u53f3\u626b\u63cf\uff0c\u76f4\u5230\u626b\u5230\u4e0d\u76f8\u7b49\u7684\u8bb0\u5f55\u3002\u4e0d\u76f8\u7b49\u7684\u8bb0\u5f55\u4e0a\uff0c\u4e0d\u52a0\u9501\u3002\u6240\u4ee5\u8868\u73b0\u4e0a\u6765\u770b\u3002<\/li>\n\n\n\n<li><ul><li>\u5f53\u67e5\u8be2\u7684\u8bb0\u5f55\u5982\u679c\u4e0d\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u95f4\u9699\u9501\u3002<\/li><li>\u5f53\u67e5\u8be2\u7684\u8bb0\u5f55\u5b58\u5728\uff0c\u4f1a\u7ed9\u67e5\u8be2\u5230\u7684\u7b49\u503c\u8bb0\u5f55\uff0c\u52a0\u4e34\u952e\u9501\uff0c\u56e0\u4e3a\u975e\u552f\u4e00\uff0c\u6240\u4ee5\u8981\u7ed9\u533a\u95f4\u52a0\u9501\uff0c\u6240\u4ee5\u662f\u4e34\u952e\u9501\uff0c\u533a\u95f4\u5185\u5305\u542b\u591a\u6761\u76f8\u540c\u503c\u3002 \u56e0\u4e3a\u975e\u552f\u4e00\uff0c\u6240\u4ee5\u5411\u53f3\u7ee7\u7eed\u626b\u63cf\uff0c\u76f4\u5230\u626b\u5230\u4e0d\u76f8\u7b49\u8bb0\u5f55\u4e3a\u6b62\uff0c\u53f3\u533a\u95f4\u9000\u5316\u4e3a\u95f4\u9699\u9501\u3002<\/li><\/ul>\u4e3a\u4ec0\u4e48\u8981\u5411\u53f3\u626b\u63cf\u76f4\u5230\u9047\u4e0a\u4e0d\u7b49\u503c\u8bb0\u5f55\uff0c\u7136\u540e\u52a0\u95f4\u9699\u9501\uff1f\u9632\u6b62\u5e7b\u8bfb\u56e0\u4e3a\u975e\u552f\u4e00\uff0c\u5982\u679c\u53ea\u5728\u7b49\u503c\u8bb0\u5f55\u4e0a\u52a0\u4e34\u952e\u9501\uff0c\u90a3\u4e48\u63d2\u5165\u548c\u5f53\u524d\u67e5\u8be2\u503c\u76f8\u540c\u7684\u503c\u7684\u8bb0\u5f55\uff0c\u5c31\u4f1a\u51fa\u73b0\u5e7b\u8bfb\uff0c\u6240\u4ee5\u8981\u5bf9\u7b49\u503c\u8bb0\u5f55\u53f3\u8fb9\u7684\u95f4\u9699\u52a0\u9501\u3002<\/li>\n\n\n\n<li><strong>\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2<\/strong> \u5148\u62c6\u5206\u6761\u4ef6\uff0c\u62c6\u51fa\u4e00\u4e2a\u7b49\u4e8e\uff0c\u6bd4\u5982\u00a0<code>>=<\/code>\u00a0\u62c6\u6210\u00a0<code>=<\/code>\u00a0\u548c\u00a0<code>><\/code> \u7b49\u503c\u6309\u7167\u4e4b\u524d\u7684\u89c4\u5219\uff0c\u5982\u679c\u67e5\u8be2\u7684\u503c\u5b58\u5728\u964d\u7ea7\u4e3a\u884c\u9501\uff0c\u67e5\u8be2\u7684\u503c\u4e0d\u5b58\u5728\uff0c\u964d\u7ea7\u4e3a\u95f4\u9699\u9501 \u4e0d\u7b49\u503c\u67e5\u8be2\uff0c\u78b0\u5230\u7b2c\u4e00\u4e2a\u4e0d\u6ee1\u8db3\u7684\u8bb0\u5f55\u65f6\uff0c\u964d\u7ea7\u4e3a\u95f4\u9699\u9501\u3002<\/li>\n\n\n\n<li><strong>\u975e\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2<\/strong> \u5148\u62c6\u5206\u6761\u4ef6\uff0c\u62c6\u6210\u7b49\u4e8e\u548c\u5927\u4e8e\u548c\u5c0f\u4e8e\uff0c\u6bd4\u5982\u00a0<code>>=<\/code>\u00a0\u62c6\u6210\u00a0<code>=<\/code>\u00a0\u548c\u00a0<code>><\/code> \u7b49\u503c\u6309\u7167\u4e4b\u524d\u7684\u89c4\u5219\uff0c\u5982\u679c\u67e5\u8be2\u7684\u503c\u5b58\u5728\u52a0\u4e34\u5efa\u9501\uff0c\u53f3\u533a\u95f4\u52a0\u95f4\u9699\u9501\uff0c\u67e5\u8be2\u7684\u503c\u4e0d\u5b58\u5728\uff0c\u964d\u7ea7\u4e3a\u95f4\u9699\u9501 \u4e0d\u7b49\u503c\u67e5\u8be2\uff0c\u78b0\u5230\u7b2c\u4e00\u4e2a\u4e0d\u6ee1\u8db3\u7684\u7d22\u5f15\u8bb0\u5f55\u65f6\uff0c\u52a0<strong>\u4e34\u952e\u9501<\/strong><\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"3limit-\u89c4\u5219\">3\uff09limit \u89c4\u5219<\/h4>\n\n\n\n<p>\u6ee1\u8db3limit\u6761\u4ef6\u540e\uff0c\u7ec8\u6b62\u8303\u56f4\u626b\u63cf<\/p>\n\n\n\n<p>\u6bd4\u5982\uff1a\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u7b49\u503c\u67e5\u8be2\uff0c\u5f53\u67e5\u8be2\u7684\u8bb0\u5f55\u5b58\u5728\uff0c\u4f1a\u7ed9\u67e5\u8be2\u5230\u7684\u7b49\u503c\u8bb0\u5f55\uff0c\u52a0\u4e34\u952e\u9501<\/p>\n\n\n\n<p>\u65e0limit\u6761\u4ef6\u7684\u60c5\u51b5\u4e0b\uff0c\u4f1a\u7ee7\u7eed\u5411\u53f3\u626b\u63cf\uff0c\u76f4\u5230\u4e0d\u7b26\u5408\u6761\u4ef6\u4e3a\u6b62\u3002\u5411\u53f3\u626b\u63cf\u7684\u533a\u95f4\uff0c\u52a0\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u5b58\u5728limit\u6761\u4ef6\uff0c\u5f53\u7b26\u5408limit\u6761\u4ef6\u4e4b\u540e\uff0c\u5c06\u4e0d\u7ee7\u7eed\u626b\u63cf\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"4order-\u89c4\u5219\">4\uff09order \u89c4\u5219<\/h4>\n\n\n\n<p>\u6ce8\u610f\u5012\u5e8f\uff0c\u524d\u5f00\u540e\u95ed\u7684\u533a\u95f4\uff0c\u5411\u5de6\u6ed1\u52a8\uff0c\u76f4\u5230\u53f3\u8fb9\u754c\uff0c\u76f4\u5230\u78b0\u5230\u4e0d\u7b26\u5408\u7684\u8bb0\u5f55\uff0c\u4f1a\u7ed9\u4e0d\u7b26\u5408\u7684\u8bb0\u5f55\u52a0\u4e0a\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"5\u4e3b\u952e\u7d22\u5f15\u548c\u975e\u4e3b\u952e\u89c4\u5219\">5\uff09\u4e3b\u952e\u7d22\u5f15\u548c\u975e\u4e3b\u952e\u89c4\u5219<\/h4>\n\n\n\n<p>\u5982\u679c\u5728\u67e5\u8be2\u4e2d\u4f7f\u7528\u4e86\u4e8c\u7ea7\u7d22\u5f15\u5e76\u4e14\u9700\u8981\u8bbe\u7f6e\u72ec\u5360\u7684\u7d22\u5f15\u8bb0\u5f55\u9501\uff0cInnoDB \u8fd8\u4f1a\u68c0\u7d22\u76f8\u5e94\u7684\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u5e76\u5bf9\u5176\u8bbe\u7f6e\u9501\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u56e0\u4e3a\u4fee\u6539\u64cd\u4f5c\uff0c\u6700\u7ec8\u8981\u56de\u8868\u5230\u805a\u7c07\u7d22\u5f15\uff0c\u5728\u805a\u7c07\u7d22\u5f15\u4e0a\u4fee\u6539\u6570\u636e\u3002\u6240\u4ee5\u5bf9\u4e8c\u7ea7\u7d22\u5f15\u52a0\u72ec\u5360\u9501\u7684\u540c\u65f6\uff0c\u4f1a\u5bf9\u4e3b\u952e\u7d22\u52a0<strong>\u884c\u9501\u3002<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p>\u67e5\u8be2\u4e2d\u4f7f\u7528\u4e8c\u7ea7\u7d22\u5f15\uff0c\u4f46\u975e\u8986\u76d6\u7d22\u5f15\uff0c\u5219\u4f1a\u5bf9\u4e3b\u952e\u7d22\u5f15\u540c\u65f6\u8fdb\u884c\u52a0\u9501\uff0c\u56e0\u4e3a\u9700\u8981\u56de\u8868\u5230\u4e3b\u952e\u7d22\u5f15\u4e0a\u3002\u4e3b\u952e\u7d22\u5f15\u53ea\u52a0\u8bb0\u5f55\u9501\uff0c\u4e8c\u7ea7\u7d22\u5f15\u53ef\u4ee5\u52a0\u8303\u56f4\u9501+\u8bb0\u5f55\u9501\u3002<\/p>\n\n\n\n<p>\u67e5\u8be2\u4e2d\u4f7f\u7528\u4e8c\u7ea7\u7d22\u5f15\uff0c\u5e76\u4e14\u662f\u8986\u76d6\u7d22\u5f15\uff0c\u5982\u679c\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u662f\u5171\u4eab\u9501\uff0c\u90a3\u4e48\u4e0d\u4f1a\u5bf9\u4e3b\u952e\u7d22\u5f15\u8fdb\u884c\u52a0\u9501\uff0c\u56e0\u4e3a\u4e0d\u4f1a\u8bbf\u95ee\u4e3b\u952e\u7d22\u5f15\u4e0a\u7684\u6570\u636e\u3002\u5982\u679c\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u52a0\u4e86\u72ec\u5360\u9501\uff0c\u5219\u5bf9\u5e94\u7684\u4e3b\u952e\u7d22\u5f15\uff0c\u4e5f\u4f1a\u88ab\u4e0a\u9501\uff0c\u4e3b\u952e\u7d22\u5f15\u53ea\u52a0\u8bb0\u5f55\u9501\uff0c\u4e8c\u7ea7\u7d22\u5f15\u53ef\u4ee5\u662f\u8303\u56f4\u9501+\u8bb0\u5f55\u9501\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"62-select\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501\">6.2 SELECT\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501<\/h3>\n\n\n\n<p><code>SELECT ... FROM<\/code>\uff0c\u5b83\u662f\u4e00\u4e2a\u4e00\u81f4\u6027\u8bfb\u53d6\uff0c\u4f1a\u8bfb\u53d6\u6570\u636e\u5e93\u7684\u5feb\u7167\uff0c\u8bfb\u53d6\u7684\u8fc7\u7a0b\u4e2d\uff0c\u5ffd\u7565\u8bfb\u53d6\u89c6\u56fe\u4e2d\u5b58\u5728\u7684\u8bb0\u5f55\u4e0a\u7684\u4efb\u4f55\u9501\u3002\u5e76\u4e14\u4e0d\u4f1a\u8bbe\u7f6e\u4efb\u4f55\u9501\u3002\u9664\u975e\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u8bbe\u7f6e\u4e3a<code>SERIALIZABLE<\/code>\u3002\u5728&nbsp;<code>SERIALIZABLE<\/code>&nbsp;\u7ea7\u522b\u4e0b\uff0c\u641c\u7d22\u4f1a\u5bf9\u5176\u9047\u5230\u7684\u7d22\u5f15\u8bb0\u5f55\u8bbe\u7f6e\u5171\u4eab\u7684\u4e34\u952e\u9501\u3002\u5bf9\u4e8e\u4f7f\u7528\u552f\u4e00\u7d22\u5f15\u6765\u67e5\u627e\u552f\u4e00\u884c\u7684\u8bed\u53e5\uff0c\u53ea\u6dfb\u52a0\u8bb0\u5f55\u9501\u3002<\/p>\n\n\n\n<p><code>SELECT ... FOR UPDATE<\/code>&nbsp;\u548c&nbsp;<code>SELECT ... FOR SHARE<\/code>&nbsp;\u8bed\u53e5\u5728\u4f7f\u7528\u552f\u4e00\u7d22\u5f15\u65f6\u4f1a\u4e3a\u626b\u63cf\u5230\u7684\u884c\u83b7\u53d6\u9501\uff0c\u5e76\u5bf9\u4e0d\u7b26\u5408\u7ed3\u679c\u96c6\u6761\u4ef6\u7684\u884c\uff08\u4f8b\u5982\u4e0d\u6ee1\u8db3 WHERE \u5b50\u53e5\u4e2d\u7684\u6761\u4ef6\uff09\u91ca\u653e\u9501\u3002<\/p>\n\n\n\n<p><strong>\u4e3b\u952e\u7d22\u5f15\u548c\u4e8c\u7ea7\u7d22\u5f15\u52a0\u9501\u60c5\u51b5<\/strong><\/p>\n\n\n\n<p><code>SELECT ... FOR UPDATE<\/code>&nbsp;\u5728\u5bf9\u4e8c\u7ea7\u7d22\u5f15\u52a0\u9501\u7684\u540c\u65f6\uff0c\u4f1a\u5bf9\u4e3b\u952e\u7d22\u5f15\u52a0\u9501\u3002\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u5982\u679c\u52a0\u4e86\u4e34\u952e\u9501\uff0c\u56de\u8868\u5230\u4e3b\u952e\u7d22\u5f15\u52a0\u7684\u662f\u884c\u9501\u3002<\/p>\n\n\n\n<p><code>SELECT ... FOR SHARE<\/code>&nbsp;\u5982\u679c\u662f\u8986\u76d6\u7d22\u5f15\uff0c\u5219\u53ea\u5728\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u52a0\u9501\uff0c\u4e0d\u4f1a\u5bf9\u4e3b\u952e\u7d22\u5f15\u52a0\u9501\u3002\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u5982\u679c\u52a0\u4e86\u4e34\u952e\u9501\uff0c\u56de\u8868\u5230\u4e3b\u952e\u7d22\u5f15\u52a0\u7684\u662f\u884c\u9501\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u6ce8\u610f\uff1a\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u7531\u4e8e\u5728\u67e5\u8be2\u6267\u884c\u8fc7\u7a0b\u4e2d\u7ed3\u679c\u884c\u4e0e\u5176\u539f\u59cb\u6765\u6e90\u7684\u5173\u7cfb\u4e22\u5931\uff0c\u884c\u53ef\u80fd\u4e0d\u4f1a\u7acb\u5373\u89e3\u9501\u3002<\/p>\n\n\n\n<p>\u4f8b\u5982\uff0c\u5728&nbsp;<code>UNION<\/code>&nbsp;\u4e2d\uff0c\u4ece\u8868\u4e2d\u626b\u63cf\uff08\u5e76\u9501\u5b9a\uff09\u7684\u884c\u53ef\u80fd\u4f1a\u5728\u63d2\u5165\u4e34\u65f6\u8868\u540e\u624d\u88ab\u8bc4\u4f30\u662f\u5426\u7b26\u5408\u7ed3\u679c\u96c6\u6761\u4ef6\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4e34\u65f6\u8868\u4e2d\u7684\u884c\u4e0e\u539f\u59cb\u8868\u4e2d\u7684\u884c\u4e4b\u95f4\u7684\u5173\u7cfb\u4e22\u5931\uff0c\u56e0\u6b64\u539f\u59cb\u8868\u4e2d\u7684\u884c\u5728\u67e5\u8be2\u6267\u884c\u7ed3\u675f\u4e4b\u524d\u4e0d\u4f1a\u88ab\u89e3\u9501\u3002<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"63-update\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501\">6.3 UPDATE\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501<\/h3>\n\n\n\n<p><code>UPDATE ... WHERE ...<\/code>&nbsp;\u4f1a\u5bf9\u641c\u7d22\u9047\u5230\u7684\u6bcf\u4e2a\u8bb0\u5f55\u8bbe\u7f6e\u72ec\u5360\u7684\u4e34\u952e\u9501\u3002<\/p>\n\n\n\n<p>\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u60c5\u51b5\u540c\u901a\u7528\u89c4\u5219\u3002\u67e5\u8be2\u8bb0\u5f55\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u72ec\u5360\u7684\u8bb0\u5f55\u9501\u3002\u67e5\u8be2\u8bb0\u5f55\u4e0d\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u72ec\u5360\u7684\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<p>\u5f53&nbsp;<code>UPDATE<\/code>&nbsp;\u4fee\u6539\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u65f6\uff0c\u4f1a\u5bf9\u53d7\u5f71\u54cd\u7684\u4e8c\u7ea7\u7d22\u5f15\u8bb0\u5f55\u9690\u5f0f\u52a0\u9501\u3002<\/p>\n\n\n\n<p><code>UPDATE<\/code>&nbsp;\u4fee\u6539\u552f\u4e00\u7d22\u5f15\u65f6\uff0c\u9700\u8981\u5220\u9664\u65e7\u7684\u7d22\u5f15\uff0c\u63d2\u5165\u65b0\u7684\u7d22\u5f15\u3002\u65e7\u7684\u7d22\u5f15\u8bb0\u5f55\u4e0a\u4f1a\u52a0\u4e0a\u8bb0\u5f55\u9501\uff0c\u63d2\u5165\u7684\u65b0\u7d22\u5f15\u8bb0\u5f55\u5219\u9690\u5f0f\u52a0\u9501\u3002<code>\u52a0\u9501\u7684\u903b\u8f91 = DELETE\u64cd\u4f5c + INSERT\u64cd\u4f5c<\/code>\u3002<\/p>\n\n\n\n<p>\u5728\u552f\u4e00\u7d22\u5f15\u4e0a\u63d2\u5165\u65b0\u7684\u7d22\u5f15\u8bb0\u5f55\u4e4b\u524d\uff0c<code>UPDATE<\/code>&nbsp;\u64cd\u4f5c\u8fd8\u4f1a\u5728\u6267\u884c\u91cd\u590d\u68c0\u67e5\u626b\u63cf\u65f6\u5bf9\u53d7\u5f71\u54cd\u7684\u7d22\u5f15\u8bb0\u5f55\u52a0\u5171\u4eab\u9501\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"64-delete\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501\">6.4 DELETE\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501<\/h3>\n\n\n\n<p><code>DELETE FROM ... WHERE ...<\/code>&nbsp;\u5bf9\u641c\u7d22\u9047\u5230\u7684\u6bcf\u4e2a\u8bb0\u5f55\u8bbe\u7f6e\u72ec\u5360\u7684\u4e34\u952e\u9501\u3002<\/p>\n\n\n\n<p>\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u60c5\u51b5\u540c\u901a\u7528\u89c4\u5219\u3002\u67e5\u8be2\u8bb0\u5f55\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u72ec\u5360\u7684\u8bb0\u5f55\u9501\u3002\u67e5\u8be2\u8bb0\u5f55\u4e0d\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u72ec\u5360\u7684\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"65-insert\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501\">6.5 INSERT\u8bed\u53e5\u8bbe\u7f6e\u7684\u9501<\/h3>\n\n\n\n<p>\u53c2\u8003\u63d2\u5165\u610f\u5411\u9501\u548c\u9690\u5f0f\u9501<\/p>\n\n\n\n<p>\u666e\u901aINSERT\u8bed\u53e5\uff0c\u53ea\u6709\u9690\u5f0f\u9501\uff0c\u53c2\u8003\u9690\u5f0f\u9501\u7ae0\u8282\u3002<\/p>\n\n\n\n<p>\u5f53\u63d2\u5165\u7684\u95f4\u9699\uff0c\u5b58\u5728\u610f\u5411\u9501\u7684\u65f6\u5019\uff0c\u5219\u53bb\u83b7\u53d6\u63d2\u5165\u610f\u5411\u9501\u3002\u53c2\u8003\u63d2\u5165\u610f\u5411\u9501\u7ae0\u8282\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"7-\u9644\u5f55\">7. \u9644\u5f55<\/h2>\n\n\n\n<p><strong>\u95f4\u9699\u9501\u52a0\u9501\u89c4\u5219\uff08\u517111\u4e2a\u6848\u4f8b\uff09<\/strong><\/p>\n\n\n\n<p>\u95f4\u9699\u9501\u662f\u5728\u53ef\u91cd\u590d\u8bfb\u9694\u79bb\u7ea7\u522b\u4e0b\u624d\u4f1a\u751f\u6548\u7684\uff1a<code>next-key lock<\/code>\u5b9e\u9645\u4e0a\u662f\u7531\u95f4\u9699\u9501\u52a0\u884c\u9501\u5b9e\u73b0\u7684\uff0c\u5982\u679c\u5207\u6362\u5230\u8bfb\u63d0\u4ea4\u9694\u79bb\u7ea7\u522b (read-committed) \u7684\u8bdd\uff0c\u5c31\u597d\u7406\u89e3\u4e86\uff0c\u8fc7\u7a0b\u4e2d\u53bb\u6389\u95f4\u9699\u9501\u7684\u90e8\u5206\uff0c\u4e5f\u5c31\u662f\u53ea\u5269\u4e0b\u884c\u9501\u7684\u90e8\u5206\u3002\u800c<strong>\u5728\u8bfb\u63d0\u4ea4\u9694\u79bb\u7ea7\u522b\u4e0b<\/strong>\u95f4\u9699\u9501\u5c31\u6ca1\u6709\u4e86\uff0c**\u4e3a\u4e86\u89e3\u51b3\u53ef\u80fd\u51fa\u73b0\u7684\u6570\u636e\u548c\u65e5\u5fd7\u4e0d\u4e00\u81f4\u95ee\u9898\uff0c\u9700\u8981\u628abinlog \u683c\u5f0f\u8bbe\u7f6e\u4e3a row **\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u8bb8\u591a\u516c\u53f8\u7684\u914d\u7f6e\u4e3a\uff1a\u8bfb\u63d0\u4ea4\u9694\u79bb\u7ea7\u522b\u52a0&nbsp;<code>binlog_format=row<\/code>\u3002\u4e1a\u52a1\u4e0d\u9700\u8981\u53ef\u91cd\u590d\u8bfb\u7684\u4fdd\u8bc1\uff0c\u8fd9\u6837\u8003\u8651\u5230\u8bfb\u63d0\u4ea4\u4e0b\u64cd\u4f5c\u6570\u636e\u7684\u9501\u8303\u56f4\u66f4\u5c0f\uff08\u6ca1\u6709\u95f4\u9699\u9501\uff09\uff0c\u8fd9\u4e2a\u9009\u62e9\u662f\u5408\u7406\u7684\u3002<\/p>\n\n\n\n<p><strong>next-key lock\u7684\u52a0\u9501\u89c4\u5219<\/strong><\/p>\n\n\n\n<p>\u603b\u7ed3\u7684\u52a0\u9501\u89c4\u5219\u91cc\u9762\uff0c\u5305\u542b\u4e86\u4e24\u4e2a\u539f\u5219\u3001\u4e24\u4e2a\u4f18\u5316\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u539f\u52191 \uff1a\u52a0\u9501\u7684\u57fa\u672c\u5355\u4f4d\u662f<code>next-key lock<\/code>\u3002<code>next-key lock<\/code>\u662f\u524d\u5f00\u540e\u95ed\u533a\u95f4\u3002<\/li>\n\n\n\n<li>\u539f\u52192 \uff1a\u67e5\u627e\u8fc7\u7a0b\u4e2d\u8bbf\u95ee\u5230\u7684\u5bf9\u8c61\u624d\u4f1a\u52a0\u9501\u3002<\/li>\n\n\n\n<li>\u4f18\u53161 \uff1a\u7d22\u5f15\u4e0a\u7684\u7b49\u503c\u67e5\u8be2\uff0c\u7ed9\u552f\u4e00\u7d22\u5f15\u52a0\u9501\u7684\u65f6\u5019\uff0c<code>next-key lock<\/code>\u9000\u5316\u4e3a\u884c\u9501\u3002<\/li>\n\n\n\n<li>\u4f18\u53162 \uff1a\u7d22\u5f15\u4e0a\u7684\u7b49\u503c\u67e5\u8be2\uff0c\u7ed9\u975e\u552f\u4e00\u7d22\u5f15\u52a0\u9501\u7684\u65f6\u5019\uff0c\u5411\u53f3\u904d\u5386\u65f6\u4e14\u6700\u540e\u4e00\u4e2a\u503c\u4e0d\u6ee1\u8db3\u7b49\u503c\u6761\u4ef6\u7684\u65f6\u5019\uff0c\u00a0<code>next-keylock<\/code>\u9000\u5316\u4e3a\u95f4\u9699\u9501\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u6211\u4eec\u4ee5\u8868test\u4f5c\u4e3a\u4f8b\u5b50\uff0c\u5efa\u8868\u8bed\u53e5\u548c\u521d\u59cb\u5316\u8bed\u53e5\u5982\u4e0b\uff1a\u5176\u4e2did\u4e3a\u4e3b\u952e\u7d22\u5f15<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE TABLE `test` (\n    `id` int(11) NOT NULL,\n    `col1` int(11) DEFAULT NULL,\n    `col2` int(11) DEFAULT NULL,\n    PRIMARY KEY (`id`),\n    KEY `c` (`col1`)\n) ENGINE=InnoDB;\ninsert into test values(0,0,0),(5,5,5),\n(10,10,10),(15,15,15),(20,20,20),(25,25,25);<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b1\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\">\u6848\u4f8b1\uff1a\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><th>sessionC<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>update test set col2 = col2+1 where id=7;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>insert into test values(8,8,8)<br>(blocked)<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>update test set col2 = col2+1 where id=10;<br>(Query OK)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>sessionA \u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u67e5\u8be2\u7684\u8bb0\u5f55\u4e0d\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u95f4\u9699\u9501\uff0c\u9501\u5b9a\u95f4\u9699(5,10)\uff0c\u56e0\u4e3a\u662fUpdate\u64cd\u4f5c\uff0c\u6240\u4ee5\u8bbe\u7f6e\u662f\u72ec\u5360\u7684\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<p>sessionC \u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u67e5\u8be2\u7684\u8bb0\u5f55\u5b58\u5728\uff0c\u4e34\u952e\u9501\u9000\u5316\u4e3a\u8bb0\u5f55\u9501\uff0c\u53ea\u9501\u5b9a\u4e00\u6761\u8bb0\u5f55id=10\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>*************************** Session A ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:4:4:140058950704768\nENGINE_TRANSACTION_ID: 122892\n            THREAD_ID: 48\n             EVENT_ID: 16\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 140058950704768\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 10\n*************************** Session C ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585968:40:4:4:140058950710992\nENGINE_TRANSACTION_ID: 122896\n            THREAD_ID: 49\n             EVENT_ID: 37\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 140058950710992\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,REC_NOT_GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 10\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b2\u975e\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\">\u6848\u4f8b2\uff1a\u975e\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><th>sessionC<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>select id from test where col1 = 5 lock in share mode;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>update test set col2 = col2+1 where id=5;<br>(Query OK)<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>insert into test values(7,7,7);<br>(blocked)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SessionA \u975e\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2<\/li>\n<\/ul>\n\n\n\n<p>\u67e5\u8be2\u7684\u503c col1=5 \u5b58\u5728\uff0c\u52a0\u4e34\u952e\u9501 (0,5]<\/p>\n\n\n\n<p>\u56e0\u4e3a\u662f\u975e\u552f\u4e00\u7d22\u5f15\uff0c\u7ee7\u7eed\u5411\u53f3\u904d\u5386\uff0c\u76f4\u5230\u9047\u5230\u7b2c\u4e00\u6761\u4e0d\u6ee1\u8db3\u6761\u4ef6\u7684\u7d22\u5f15col1=10\uff0c\u4e34\u952e\u9501\u964d\u7ea7\u4e3a\u95f4\u9699\u9501(5,10)<\/p>\n\n\n\n<p>\u56e0\u4e3a\u662f\u8986\u76d6\u7d22\u5f15\uff0c\u4e14\u662f\u5171\u4eab\u9501\uff0c\u5e76\u4e0d\u9700\u8981\u8bbf\u95ee\u4e3b\u952e\u7d22\u5f15\uff0c\u6240\u4ee5\u4e0d\u5bf9\u4e3b\u952e\u7d22\u5f15\u8fdb\u884c\u52a0\u9501<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SessionB \u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2<\/li>\n<\/ul>\n\n\n\n<p>\u56e0\u4e3a\uff0cSessionA\u53ea\u5728\u7d22\u5f15c\u4e0a\u52a0\u9501\uff0c\u6ca1\u6709\u5bf9\u4e3b\u952e\u7d22\u5f15\u8fdb\u884c\u52a0\u9501<\/p>\n\n\n\n<p>\u6240\u4ee5 SessionB \u5bf9\u4e3b\u952e\u7d22\u5f15\u52a0\u9501\uff0c\u4e0d\u4f1a\u88ab\u963b\u585e<\/p>\n\n\n\n<p>\u5982\u679c SessionA \u662f for update\uff0c\u72ec\u5360\u9501\uff0c\u4f1a\u540c\u65f6\u5bf9\u4e3b\u952e\u7d22\u5f15\u52a0\u884c\u9501\uff0c\u5219 SessionB \u7684\u64cd\u4f5c\u4f1a\u88ab\u963b\u585e<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Session C \u8981\u63d2\u5165\u4e00\u4e2a (7,7,7) \u7684\u8bb0\u5f55\uff0c\u88ab Session A \u7684\u95f4\u9699\u9501 (5,10) \u9501\u4f4f<\/li>\n<\/ul>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>[!important]<\/p>\n\n\n\n<p>\u5982\u679c\u8981\u7528 lock in share mode\u6765\u7ed9\u884c\u52a0\u8bfb\u9501\u907f\u514d\u6570\u636e\u88ab\u66f4\u65b0\u7684\u8bdd\uff0c\u5c31\u5fc5\u987b\u5f97\u7ed5\u8fc7\u8986\u76d6\u7d22\u5f15\u7684\u4f18\u5316\uff0c\u56e0\u4e3a\u8986\u76d6\u7d22\u5f15\u4e0d\u4f1a\u8bbf\u95ee\u4e3b\u952e\u7d22\u5f15\uff0c\u4e0d\u4f1a\u7ed9\u4e3b\u952e\u7d22\u5f15\u4e0a\u52a0\u9501<\/p>\n<\/blockquote>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b3\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be21\">\u6848\u4f8b3\uff1a\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be21<\/h4>\n\n\n\n<p>\u4e0a\u9762\u4e24\u4e2a\u4f8b\u5b50\u662f\u7b49\u503c\u67e5\u8be2\u7684\uff0c\u8fd9\u4e2a\u4f8b\u5b50\u662f\u5173\u4e8e\u8303\u56f4\u67e5\u8be2\u7684\uff0c\u4e5f\u5c31\u662f\u8bf4\u4e0b\u9762\u7684\u8bed\u53e5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select * from test where id=10 for update\nselect * from tets where id&gt;=10 and id&lt;11 for update;\n<\/code><\/pre>\n\n\n\n<p>\u8fd9\u4e24\u6761\u67e5\u8bed\u53e5\u80af\u5b9a\u662f\u7b49\u4ef7\u7684\uff0c\u4f46\u662f\u5b83\u4eec\u7684\u52a0\u9501\u89c4\u5219\u4e0d\u592a\u4e00\u6837<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><th>sessionC<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>select * from test where id&gt;=10 and id&lt;11 for update;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>insert into test values(8,8,8);<br>(Query OK)<br>insert into test values(13,13,13); (blocked)<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>update test set col2=col2+1 where id=15; (Query OK)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u5148\u62c6\u5206\u51fa\u7b49\u503c\u6761\u4ef6 id = 10\uff0c\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u67e5\u8be2\u7684\u503c\u5b58\u5728\uff0c\u964d\u7ea7\u4e3a\u884c\u9501\u3002\u9501\u4f4fid=10\u8fd9\u4e00\u884c<\/p>\n\n\n\n<p>\u56e0\u4e3a\u662f\u8303\u56f4\u67e5\u8be2\uff0c\u4ece\u5de6\u5f80\u53f3\u904d\u5386\uff0c\u76f4\u5230\u9047\u5230\u7b2c\u4e00\u6761\u4e0d\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u7d22\u5f15\u8bb0\u5f55id=15\uff0c\u4e34\u952e\u9501\u964d\u7ea7\u4e3a\u95f4\u9699\u9501\u3002\u9501\u4f4f\u95f4\u9699\uff0810,15)<\/p>\n\n\n\n<p>\u6700\u7ec8\uff0csession A \u9501\u7684\u8303\u56f4\u5c31\u662f\u4e3b\u952e\u7d22\u5f15\u4e0a\uff0c\u884c\u9501 id=10 \u548c \u95f4\u9699\u9501(10,15\uff09\u3002<\/p>\n\n\n\n<p><strong>\u9996\u6b21 session A \u5b9a\u4f4d\u67e5\u627eid=10 \u7684\u884c\u7684\u65f6\u5019\uff0c\u662f\u5f53\u505a\u7b49\u503c\u67e5\u8be2\u6765\u5224\u65ad\u7684\uff0c\u800c\u5411\u53f3\u626b\u63cf\u5230 id=15 \u7684\u65f6\u5019\uff0c\u7528\u7684\u662f\u8303\u56f4\u67e5\u8be2\u5224\u65ad\u3002<\/strong><\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b4\u975e\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2\">\u6848\u4f8b4\uff1a\u975e\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2<\/h4>\n\n\n\n<p>\u4e0e\u6848\u4f8b\u4e09\u4e0d\u540c\u7684\u662f\uff0c\u6848\u4f8b\u56db\u4e2d\u67e5\u8be2\u8bed\u53e5\u7684 where \u90e8\u5206\u7528\u7684\u662f\u5b57\u6bb5 col1 \uff0c\u5b83\u662f\u666e\u901a\u7d22\u5f15<\/p>\n\n\n\n<p>\u8fd9\u4e24\u6761\u67e5\u8bed\u53e5\u80af\u5b9a\u662f\u7b49\u4ef7\u7684\uff0c\u4f46\u662f\u5b83\u4eec\u7684\u52a0\u9501\u89c4\u5219\u4e0d\u592a\u4e00\u6837<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># IX\u8868\u7ea7\u9501 \u7d22\u5f15C\u4e0a (5,10] (10,15) \u4e3b\u952e\u7d22\u5f15\u4e0a \u884c\u7ea7\u9501 10\nselect * from test where col1=10 for update; \n\n# IX\u8868\u7ea7\u9501 \u7d22\u5f15C\u4e0a \u95f4\u9699\u9501(5,10] (10,15] \u4e3b\u952e\u7d22\u5f15\u4e0a \u884c\u7ea7\u9501 10\nselect * from test where col1&gt;=10 and col1&lt;11 for update;\n<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><th>sessionC<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>select * from test where col1&gt;=10 and col1&lt;11 for update;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>insert into test values(8,8,8);<br>(blocked)<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>update test set col2=col2+1 where id=15;<br>(Query OK)<\/td><\/tr><tr><td><\/td><td><\/td><td>update test set col1=col1+1 where id=15;<br>(blocked)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u975e\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2\uff0c\u4ece\u5de6\u5f80\u53f3\u626b\u63cf\uff0c\u76f4\u5230\u9047\u5230\u7b2c\u4e00\u6761\u4e0d\u6ee1\u8db3\u67e5\u8be2\u6761\u4ef6\u7684\u7d22\u5f15\u8bb0\u5f55\uff0c\u626b\u5230\u7684\u7d22\u5f15\u8bb0\u5f55\uff0c\u5168\u52a0\u4e34\u952e\u9501\u3002\u56e0\u6b64\u9501\u5b9a\u7684\u8303\u56f4\u662f\u7d22\u5f15c\u4e0a (5,10] \u548c (10,15]<\/p>\n\n\n\n<p>\u540c\u65f6\u56e0\u4e3a\u662f\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u7684\u6392\u4ed6\u9501\uff0c\u540c\u65f6\u9700\u8981\u5bf9\u4e3b\u952e\u7d22\u5f15\u8bb0\u5f55\uff0cid=10 \u548c id=15 \u52a0\u884c\u9501\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b5\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2\u95012\">\u6848\u4f8b5\uff1a\u552f\u4e00\u7d22\u5f15\u8303\u56f4\u67e5\u8be2\u95012<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><th>sessionC<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>select * from test where id&gt;10 and id&lt;=15 for update;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>update test set col2=col2+1 where id=20; (query ok)<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>insert into test values(16,16,16);<br>(query ok)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u62c6\u5206\u6761\u4ef6\uff0c\u62c6\u6210 id = 15 \u548c 10&lt;id&lt;15<\/p>\n\n\n\n<p>id=15\uff0c\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u884c\u9501\u9501\u5b9a15<\/p>\n\n\n\n<p>10&lt;id&lt;15\uff0c\u9047\u5230\u7b2c\u4e00\u4e2a\u4e0d\u7b26\u5408\u6761\u4ef6\u7684\u503c\uff0c15\uff0c\u964d\u7ea7\u4e3a\u95f4\u9699\u9501\uff0c\u9501\u5b9a\uff0810\uff0c15\uff09<\/p>\n\n\n\n<p>\u56e0\u6b64\u603b\u7684\u9501\u5b9a\u8303\u56f4\u4e3a \uff0810,15] \u4e34\u952e\u9501<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b6\u975e\u552f\u4e00\u7d22\u5f15\u4e0a\u5b58\u5728\u7b49\u503c\u7684\u4f8b\u5b50\">\u6848\u4f8b6\uff1a\u975e\u552f\u4e00\u7d22\u5f15\u4e0a\u5b58\u5728\"\u7b49\u503c\"\u7684\u4f8b\u5b50<\/h4>\n\n\n\n<p>\u7ed9\u8868 t \u63d2\u5165\u4e00\u6761\u65b0\u8bb0\u5f55\uff1a<code>insert into test values(30,10,30);<\/code><\/p>\n\n\n\n<p>\u4e5f\u5c31\u662f\u8bf4\uff0c\u73b0\u5728\u8868\u91cc\u9762\u6709\u4e24\u4e2acol1=10\u7684\u884c\u3002\u4f46\u662f\u5b83\u4eec\u7684\u4e3b\u952e\u503c id \u662f\u4e0d\u540c\u7684\uff08\u5206\u522b\u662f 10 \u548c 30 \uff09\uff0c\u56e0\u6b64\u8fd9\u4e24\u4e2acol1=10 \u7684\u8bb0\u5f55\u4e4b\u95f4\uff0c\u4e5f\u662f\u6709\u95f4\u9699\u7684\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><th>sessionC<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>delete from test where col1=10;<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>insert into test values(12,12,12);<br>(blocked)<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><td>update test set col2=col2+1 where col1=15;<br>(query ok)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u8fd9\u6b21\u6211\u4eec\u7528 delete \u8bed\u53e5\u6765\u9a8c\u8bc1\u3002\u6ce8\u610f\uff0cdelete \u8bed\u53e5\u52a0\u9501\u7684\u903b\u8f91\uff0c\u5176\u5b9e\u8ddf select ... for update \u662f\u7c7b\u4f3c\u7684\u3002<\/p>\n\n\n\n<p>\u8fd9\u65f6\uff0csession A \u5728\u904d\u5386\u7684\u65f6\u5019\uff0c\u5148\u8bbf\u95ee\u7b2c\u4e00\u4e2a col1=10 \u7684\u8bb0\u5f55\u3002\u540c\u6837\u5730\uff0c\u6839\u636e\u539f\u5219 1 \uff0c\u8fd9\u91cc\u52a0\u7684\u662f<br>(col1=5,id=5) \u5230 (col1=10,id=10) \u8fd9\u4e2a next-key lock \u3002<\/p>\n\n\n\n<p>\u7531\u4e8ec\u662f\u666e\u901a\u7d22\u5f15\uff0c\u6240\u4ee5\u7ee7\u7eed\u5411\u53f3\u67e5\u627e\uff0c\u76f4\u5230\u78b0\u5230 (col1=15,id=15) \u8fd9\u4e00\u884c\u5faa\u73af\u624d\u7ed3\u675f\u3002\u6839\u636e\u4f18\u5316 2 \uff0c\u8fd9\u662f<br>\u4e00\u4e2a\u7b49\u503c\u67e5\u8be2\uff0c\u5411\u53f3\u67e5\u627e\u5230\u4e86\u4e0d\u6ee1\u8db3\u6761\u4ef6\u7684\u884c\uff0c\u6240\u4ee5\u4f1a\u9000\u5316\u6210 (col1=10,id=10) \u5230 (col1=15,id=15) \u7684\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"304\" width=\"1150\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/d7c754cd6c764cf18c33fba5d5e18545.png\" alt=\"\"><\/p>\n\n\n\n<p>\u8fd9\u4e2a delete \u8bed\u53e5\u5728\u7d22\u5f15 c \u4e0a\u7684\u52a0\u9501\u8303\u56f4\uff0c\u5c31\u662f\u4e0a\u9762\u56fe\u4e2d\u84dd\u8272\u533a\u57df\u8986\u76d6\u7684\u90e8\u5206\u3002\u8fd9\u4e2a\u84dd\u8272\u533a\u57df\u5de6\u53f3\u4e24\u8fb9\u90fd<br>\u662f\u865a\u7ebf\uff0c\u8868\u793a\u5f00\u533a\u95f4\uff0c\u5373 (col1=5,id=5) \u548c (col1=15,id=15) \u8fd9\u4e24\u884c\u4e0a\u90fd\u6ca1\u6709\u9501<\/p>\n\n\n\n<p>\u5728<code>\u975e\u805a\u7c07\u7d22\u5f15<\/code>\u4e0a\uff0c\u9501\u4f4f(col1=5,id=5) \u5230 (col1=15,id=15)<\/p>\n\n\n\n<p>\u5728<code>\u805a\u7c07\u7d22\u5f15<\/code>\u4e0a\uff0c\u53ea\u9501\u4f4f col=10 \u7684\u90a3\u4e24\u884c<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b7limit\u8bed\u53e5\u52a0\u9501\">\u6848\u4f8b7\uff1alimit\u8bed\u53e5\u52a0\u9501<\/h4>\n\n\n\n<p>\u4f8b\u5b506\u4e5f\u6709\u4e00\u4e2a\u5bf9\u7167\u6848\u4f8b\uff0c\u573a\u666f\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>delete from test where col1=10 limit 2;<\/td><td><\/td><\/tr><tr><td><\/td><td>insert into test values(12,12,12);<br>(Query OK)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>session A \u7684 delete\u8bed\u53e5\u52a0\u4e86 limit 2\u3002\u4f60\u77e5\u9053\u8868 t\u91cc c=10\u7684\u8bb0\u5f55\u5176\u5b9e\u53ea\u6709\u4e24\u6761\uff0c\u56e0\u6b64\u52a0\u4e0d\u52a0 limit2\uff0c\u5220\u9664\u7684\u6548\u679c\u90fd\u662f\u4e00\u6837\u7684\u3002\u4f46\u662f\u52a0\u9501\u6548\u679c\u5374\u4e0d\u4e00\u6837<\/p>\n\n\n\n<p>\u8fd9\u662f\u56e0\u4e3a\uff0c\u6848\u4f8b\u4e03\u91cc\u7684 delete\u8bed\u53e5\u660e\u786e\u52a0\u4e86 limit2\u7684\u9650\u5236\uff0c\u56e0\u6b64\u5728\u904d\u5386\u5230 (col1=10,id=30)\u8fd9\u4e00\u884c\u4e4b\u540e\uff0c \u6ee1\u8db3\u6761\u4ef6\u7684\u8bed\u53e5\u5df2\u7ecf\u6709\u4e24\u6761\uff0c\u5faa\u73af\u5c31\u7ed3\u675f\u4e86\u3002\u56e0\u6b64\uff0c\u7d22\u5f15 col1\u4e0a\u7684\u52a0\u9501\u8303\u56f4\u5c31\u53d8\u6210\u4e86\u4ece\uff08col1=5,id=5) \u5230\uff08col1=10,id=30)\u8fd9\u4e2a\u524d\u5f00\u540e\u95ed\u533a\u95f4\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"279\" width=\"1146\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/35f5911b56d94dca87cf0617c91a31f4.png\" alt=\"\"><\/p>\n\n\n\n<p>\u8fd9\u4e2a\u4f8b\u5b50\u5bf9\u6211\u4eec\u5b9e\u8df5\u7684\u6307\u5bfc\u610f\u4e49\u5c31\u662f\uff0c\u5728\u5220\u9664\u6570\u636e\u7684\u65f6\u5019\u5c3d\u91cf\u52a0 limit\u3002<\/p>\n\n\n\n<p>\u8fd9\u6837\u4e0d\u4ec5\u53ef\u4ee5<strong>\u63a7\u5236\u5220\u9664\u6570\u636e\u7684\u6761\u6570\uff0c\u8ba9\u64cd\u4f5c\u66f4\u5b89\u5168\uff0c\u8fd8\u53ef\u4ee5\u51cf\u5c0f\u52a0\u9501\u7684\u8303\u56f4\u3002<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>select col1 from test where col1 = 5 for share;\nselect col1 from test where col1 = 5  limit 1 for share;\nselect col1 from test where col1 = 5  limit 2 for share;\n<\/code><\/pre>\n\n\n\n<p>\u8bed\u53e51\uff1a\u6ca1\u6709limit\u7684\u60c5\u51b5\u4e0b\uff0c\u7d22\u5f15C\u4e0a\u9501\u5b9a\u8303\u56f4 \uff080,5] (5,10)<\/p>\n\n\n\n<p>\u8bed\u53e52\uff1a\u5b58\u5728limit\u7684\u60c5\u51b5\u4e0b\uff0c\u7d22\u5f15C\u4e0a\u9501\u5b9a\u8303\u56f4 (0,5] \uff0climit\u9650\u5236\u53ea\u626b\u63cf\u4e00\u6761\uff0c\u4e0d\u9700\u8981\u518d\u7ee7\u7eed\u5411\u626b\u63cf\u4e86\u3002<\/p>\n\n\n\n<p>\u8bed\u53e53\uff1a\u5b58\u5728limit\u7684\u60c5\u51b5\u4e0b\uff0c\u7d22\u5f15C\u4e0a\u9501\u5b9a\u8303\u56f4 \uff080,5] (5,10) \u56e0\u4e3alimit\u8981\u626b\u4e24\u6761\uff0c\u627e\u4e0d\u5230\u7b2c\u4e8c\u6761\uff0c\u4e00\u76f4\u626b\u5230\u9047\u4e0a\u7b2c\u4e00\u6761\u4e0d\u7b26\u5408\u7684\u8bb0\u5f55\u4e3a\u6b62\uff0c\u4e34\u952e\u9501\u964d\u7ea7\u4e3a\u95f4\u9699\u9501\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b8\u4e00\u4e2a\u6b7b\u9501\u7684\u4f8b\u5b50\">\u6848\u4f8b8\uff1a\u4e00\u4e2a\u6b7b\u9501\u7684\u4f8b\u5b50<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>select id from test where col1=10 lock in share mode;<\/td><td><\/td><\/tr><tr><td><\/td><td>update test set col2=col2+1 where col1=10;<br>(blocked)<\/td><\/tr><tr><td>insert into test values(8,8,8);<\/td><td><\/td><\/tr><tr><td><\/td><td>ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sessionA\u542f\u52a8\u4e8b\u52a1\u540e\u6267\u884c\u67e5\u8be2\u8bed\u53e5\u52a0 lock in share mode\uff0c\u5728\u7d22\u5f15col1\u4e0a\u52a0\u4e86next-keylock(5,10]\u548c\u95f4\u9699\u9501 (10,15)\uff08\u7d22\u5f15\u5411\u53f3\u904d\u5386\u9000\u5316\u4e3a\u95f4\u9699\u9501\uff09\uff1b<\/li>\n\n\n\n<li>sessionB\u7684update\u8bed\u53e5\u4e5f\u8981\u5728\u7d22\u5f15c\u4e0a\u52a0next-keylock(5,10]\uff0c\u8fdb\u5165\u9501\u7b49\u5f85\uff1b\u5b9e\u9645\u4e0a\u5206\u6210\u4e86\u4e24\u6b65\uff0c\u5148\u662f\u52a0 (5,10)\u7684\u95f4\u9699\u9501\uff0c\u52a0\u9501\u6210\u529f\uff1b\u7136\u540e\u52a0col1=10\u7684\u884c\u9501\uff0c\u56e0\u4e3asessionA\u4e0a\u5df2\u7ecf\u7ed9\u8fd9\u884c\u52a0\u4e0a\u4e86\u8bfb\u9501\uff0c\u6b64\u65f6\u7533\u8bf7\u6b7b\u9501\u65f6\u4f1a\u88ab\u963b\u585e<\/li>\n\n\n\n<li>sessionA\u8981\u518d\u63d2\u5165(8,8,8)\u8fd9\u4e00\u884c\uff0c\u88ab sessionB\u7684\u95f4\u9699\u9501\u9501\u4f4f\u3002\u7531\u4e8e\u51fa\u73b0\u4e86\u6b7b\u9501\uff0cInnoDB\u8ba9 sessionB\u56de\u6eda<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b9order-by\u7d22\u5f15\u6392\u5e8f\u7684\u95f4\u9699\u95011\">\u6848\u4f8b9\uff1aorder by\u7d22\u5f15\u6392\u5e8f\u7684\u95f4\u9699\u95011<\/h4>\n\n\n\n<p>\u5982\u4e0b\u9762\u4e00\u6761\u8bed\u53e5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>begin;\n# \u6b63\u5e8f\u60c5\u51b5\u4e0b\uff0c\u9501\u5b9a(5,10]  (10,15]\nselect * from test where id>9 and id&lt;12 order by id  for update;\n\n# \u4e0b\u9762\u7684\u89e3\u91ca\u662f\u5012\u53d9\nselect * from test where id>9 and id&lt;12 order by id desc for update;\n<\/code><\/pre>\n\n\n\n<p>\u4e0b\u56fe\u4e3a\u8fd9\u4e2a\u8868\u7684\u7d22\u5f15id\u7684\u793a\u610f\u56fe\u3002<\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"132\" width=\"1153\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/2664d47d1acd432ebd4e7e8819170c7c.png\" alt=\"\"><\/p>\n\n\n\n<p>\u9996\u5148\u8fd9\u4e2a\u67e5\u8be2\u8bed\u53e5\u7684\u8bed\u4e49\u662f order by id desc \uff0c\u8981\u62ff\u5230\u6ee1\u8db3\u6761\u4ef6\u7684\u6240\u6709\u884c\uff0c\u4f18\u5316\u5668\u5fc5\u987b\u5148\u627e\u5230\u7b2c\u4e00\u4e2a id&lt;12 \u7684\u503c\u3002<\/p>\n\n\n\n<p>\u8fd9\u4e2a\u8fc7\u7a0b\u662f\u901a\u8fc7\u7d22\u5f15\u6811\u7684\u641c\u7d22\u8fc7\u7a0b\u5f97\u5230\u7684\uff0c\u5728\u5f15\u64ce\u5185\u90e8\uff0c\u5176\u5b9e\u662f\u8981\u627e\u5230 id=12 \u7684\u8fd9\u4e2a\u503c\uff0c\u53ea\u662f\u6700\u7ec8\u6ca1\u627e\u5230\uff0c\u4f46\u627e\u5230\u4e86 (10,15) \u8fd9\u4e2a\u95f4\u9699\u3002id=15 \u4e0d\u6ee1\u8db3\u6761\u4ef6\uff0c\u6240\u4ee5 next-key lock \u9000\u5316\u4e3a\u4e86\u95f4\u9699\u9501 (10,15)<\/p>\n\n\n\n<p>\u7136\u540e\u5411\u5de6\u904d\u5386\uff0c\u5728\u904d\u5386\u8fc7\u7a0b\u4e2d\uff0c\u5c31\u4e0d\u662f\u7b49\u503c\u67e5\u8be2\u4e86\uff0c\u4f1a\u626b\u63cf\u5230 id=5 \u8fd9\u4e00\u884c\uff0c\u53c8\u56e0\u4e3a\u533a\u95f4\u662f\u5de6\u5f00\u53f3<br>\u95ed\u7684\uff0c\u6240\u4ee5\u4f1a\u52a0\u4e00\u4e2anext-key lock (0,5] \u3002 \u4e5f\u5c31\u662f\u8bf4\uff0c\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\uff0c\u901a\u8fc7\u6811\u641c\u7d22\u7684\u65b9\u5f0f\u5b9a\u4f4d\u8bb0\u5f55<br>\u7684\u65f6\u5019\uff0c\u7528\u7684\u662f \u201c \u7b49\u503c\u67e5\u8be2 \u201d \u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b10order-by\u7d22\u5f15\u6392\u5e8f\u7684\u95f4\u9699\u95012\">\u6848\u4f8b10\uff1aorder by\u7d22\u5f15\u6392\u5e8f\u7684\u95f4\u9699\u95012<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>select * from test where col1&gt;=15 and col1&lt;=20 order by col1 desc lock in share mode;<\/td><td><\/td><\/tr><tr><td><\/td><td>insert into test values(6,6,6);<br>(blocked)<\/td><\/tr><tr><td><\/td><td>insert into test values(11,11,11);<br>(blocked)<\/td><\/tr><tr><td><\/td><td>update test set col2 = col2 +1 where id =10;(Query OK)<\/td><\/tr><tr><td><\/td><td>update test set col2 = col2 +1 where col1=10;(blocked)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7531\u4e8e\u662forder by col1 desc\uff0c\u7b2c\u4e00\u4e2a\u8981\u5b9a\u4f4d\u7684\u662f\u7d22\u5f15col1\u4e0a\u6700\u53f3\u8fb9\u7684col1=20\u7684\u884c\u3002\u8fd9\u662f\u4e00\u4e2a\u975e\u552f\u4e00\u7d22\u5f15\u7684\u7b49\u503c\u67e5\u8be2\uff1a \u5de6\u5f00\u53f3\u95ed\u533a\u95f4\uff0c\u9996\u5148\u52a0\u4e0a next-keylock(15,20]\u3002\u5411\u53f3\u904d\u5386\uff0ccol1=25\u4e0d\u6ee1\u8db3\u6761\u4ef6\uff0c\u9000\u5316\u4e3a\u95f4\u9699\u9501\u6240\u4ee5\u4f1a \u52a0\u4e0a\u95f4\u9699\u9501(20,25)\u548c next-keylock(15,20]\u3002<\/li>\n\n\n\n<li>\u5728\u7d22\u5f15 col1 \u4e0a\u5411\u5de6\u904d\u5386\uff0c\u8981\u626b\u63cf\u5230 col1=10 \u624d\u505c\u4e0b\u6765\u3002\u540c\u65f6\u53c8\u56e0\u4e3a\u5de6\u5f00\u53f3\u95ed\u533a\u95f4\uff0c\u6240\u4ee5 next-key lock\u4f1a\u52a0\u5230 (10,15]\uff0c\u8fd9\u6b63\u662f\u963b\u585e session B \u7684 insert into test values(11,11,11)\u8bed\u53e5\u7684\u539f\u56e0\u3002<\/li>\n\n\n\n<li>\u5728\u626b\u63cf\u8fc7\u7a0b\u4e2d\uff0ccol1=20\u3001col1=15\u3001col1=10\u8fd9\u4e09\u884c\u90fd\u5b58\u5728\u503c\uff0c\u7531\u4e8e\u662f select *\uff0c\u6240\u4ee5\u4f1a\u5728\u4e3b\u952eid\u4e0a\u52a0\u4e0a\u884c\u9501\u3002\u56e0\u6b64\uff0csession A\u7684 select\u8bed\u53e5\u9501\u7684\u8303\u56f4\u5c31\u662f\uff1a\n<ul class=\"wp-block-list\">\n<li>\u7d22\u5f15 c \u4e0a (5,10] (10,15] (15,20]\uff0820,25) \uff1b<\/li>\n\n\n\n<li>\u4e3b\u952e\u7d22\u5f15\u4e0a id=15\u300120\u4e24\u4e2a\u884c\u9501\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b11update\u7684\u4f8b\u5b50\">\u6848\u4f8b11\uff1aupdate\u7684\u4f8b\u5b50<\/h4>\n\n\n\n<p>\u5f53&nbsp;<code>UPDATE<\/code>&nbsp;\u4fee\u6539\u805a\u7c07\u7d22\u5f15\u8bb0\u5f55\u65f6\uff0c\u4f1a\u5bf9\u53d7\u5f71\u54cd\u7684\u4e8c\u7ea7\u7d22\u5f15\u8bb0\u5f55\u9690\u5f0f\u52a0\u9501\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>sessionA<\/th><th>sessionB<\/th><\/tr><\/thead><tbody><tr><td>begin;<br>update test set col1=1 where id=5;<\/td><td><\/td><\/tr><tr><td><\/td><td>update test set col1=5 where col1=1;(blocked)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>SessionA\u6267\u884cUpdate\u8bed\u53e5\uff0c\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0c\u4f1a\u5728\u805a\u7c07\u7d22\u5f15\u4e0a\u52a0\u4e00\u6761\u884c\u9501\uff0c\u9501id=5\u8fd9\u6761\u8bb0\u5f55<\/p>\n\n\n\n<p>\u5728\u4e8c\u7ea7\u7d22\u5f15C\u4e0a\uff0c\u5e76\u6ca1\u6709\u663e\u793a\u7684\u52a0\u9501<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>*************************** row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:4:3:140058950704768\nENGINE_TRANSACTION_ID: 122988\n            THREAD_ID: 63\n             EVENT_ID: 21\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 140058950704768\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,REC_NOT_GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 5\n<\/code><\/pre>\n\n\n\n<p>SessionB\u5c1d\u8bd5\u4fee\u6539\u4e8c\u7ea7\u7d22\u5f15\uff0c\u5bfc\u81f4\u4e8c\u7ea7\u7d22\u5f15\u4e0a\u7684\u9690\u5f0f\u9501\uff0c\u53d8\u4e3a\u8bb0\u5f55\u9501<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>*************************** row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:4:3:140058950704768\nENGINE_TRANSACTION_ID: 122988\n            THREAD_ID: 63\n             EVENT_ID: 21\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 140058950704768\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,REC_NOT_GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 5\n*************************** \u9690\u5f0f\u9501\u53d8\u6210\u8bb0\u5f55\u9501 ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:5:8:140058950705112\nENGINE_TRANSACTION_ID: 122988\n            THREAD_ID: 64\n             EVENT_ID: 13\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: c\nOBJECT_INSTANCE_BEGIN: 140058950705112\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,REC_NOT_GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 1, 5\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"\u6848\u4f8b12-update\u4f8b\u5b50\u975e\u552f\u4e00\u7d22\u5f15\u4e0a\u7684\u64cd\u4f5c\">\u6848\u4f8b12 Update\u4f8b\u5b50\u2014\u2014\u975e\u552f\u4e00\u7d22\u5f15\u4e0a\u7684\u64cd\u4f5c<\/h4>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Session A<\/th><th>SessionB<\/th><\/tr><\/thead><tbody><tr><td>begin<br>update test set col1=4 where col1=5;<\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u975e\u552f\u4e00\u7d22\u5f15\u7b49\u503c\u67e5\u8be2\uff0ccol1=5\u5b58\u5728\uff0c\u7d22\u5f15C\u4e0a\u9501\u5b9a\u8303\u56f4 \uff080,5] \uff085,10\uff09<\/p>\n\n\n\n<p>\u63d2\u5165\u65b0\u7684\u4e8c\u7ea7\u7d22\u5f15col1=4\uff0c\u9501\u5b9a\u8303\u56f4\uff080,4)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>*************************** 2. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:5:3:140058950704768\nENGINE_TRANSACTION_ID: 123017\n            THREAD_ID: 63\n             EVENT_ID: 74\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: c\nOBJECT_INSTANCE_BEGIN: 140058950704768\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 5, 5\n*************************** 3. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:4:3:140058950705112\nENGINE_TRANSACTION_ID: 123017\n            THREAD_ID: 63\n             EVENT_ID: 74\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: PRIMARY\nOBJECT_INSTANCE_BEGIN: 140058950705112\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,REC_NOT_GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 5\n*************************** 4. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:5:4:140058950705456\nENGINE_TRANSACTION_ID: 123017\n            THREAD_ID: 63\n             EVENT_ID: 74\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: c\nOBJECT_INSTANCE_BEGIN: 140058950705456\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 10, 10\n*************************** 5. row ***************************\n               ENGINE: INNODB\n       ENGINE_LOCK_ID: 140059072585112:40:5:8:140058950705456\nENGINE_TRANSACTION_ID: 123017\n            THREAD_ID: 63\n             EVENT_ID: 74\n        OBJECT_SCHEMA: dbtest_lock\n          OBJECT_NAME: test\n       PARTITION_NAME: NULL\n    SUBPARTITION_NAME: NULL\n           INDEX_NAME: c\nOBJECT_INSTANCE_BEGIN: 140058950705456\n            LOCK_TYPE: RECORD\n            LOCK_MODE: X,GAP\n          LOCK_STATUS: GRANTED\n            LOCK_DATA: 4, 5\n<\/code><\/pre>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u552f\u4e00\u7d22\u5f15\u7684\u8bdd\uff0cupdate\u64cd\u4f5c\uff0c\u5220\u9664\u7684\u8bb0\u5f55\u52a0\u884c\u9501\uff0c\u65b0\u7684\u8bb0\u5f55\u52a0\u9690\u5f0f\u9501<\/p>\n<\/blockquote>\n\n\n\n<p>\u200b<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u7b2c15\u7ae0_\u9501 \u4e8b\u52a1\u7684\u9694\u79bb\u6027\u7531\u9501\u6765\u5b9e\u73b0 \u9501\u662f\u8ba1\u7b97\u673a\u534f\u8c03\u591a\u4e2a\u8fdb\u7a0b\u6216\u7ebf\u7a0b\u5e76\u53d1\u8bbf\u95ee\u67d0\u4e00\u8d44\u6e90\u7684\u673a\u5236\u3002\u5728\u7a0b\u5e8f\u5f00\u53d1\u4e2d\u4f1a\u5b58\u5728\u591a\u7ebf\u7a0b\u540c\u6b65\u7684\u95ee\u9898\uff0c\u5f53\u591a &#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[2],"tags":[16],"class_list":["post-931","post","type-post","status-publish","format-standard","hentry","category-2","tag-sql"],"_links":{"self":[{"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/posts\/931","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=931"}],"version-history":[{"count":1,"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/posts\/931\/revisions"}],"predecessor-version":[{"id":935,"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/posts\/931\/revisions\/935"}],"wp:attachment":[{"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}