{"id":860,"date":"2025-02-18T18:42:24","date_gmt":"2025-02-18T10:42:24","guid":{"rendered":"https:\/\/eve2333.top\/?p=860"},"modified":"2025-02-18T18:42:43","modified_gmt":"2025-02-18T10:42:43","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-%e5%9f%ba%e7%a1%80%e7%af%87-p-10","status":"publish","type":"post","link":"https:\/\/eve2333.top\/?p=860","title":{"rendered":"MySQL\u6570\u636e\u5e93\u5165\u95e8\u5230\u5927\u86c7\u5c1a\u7845\u8c37\u5b8b\u7ea2\u5eb7\u8001\u5e08\u7b14\u8bb0 \u57fa\u7840\u7bc7 part 13"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">&nbsp;\u7b2c13\u7ae0_\u7ea6\u675fconstraint<\/h1>\n\n\n\n<p>\u6570\u636e\u5b8c\u6574\u6027\uff08Data Integrity\uff09\u662f\u6307\u6570\u636e\u7684\u7cbe\u786e\u6027\uff08Accuracy\uff09\u548c\u53ef\u9760\u6027\uff08Reliability\uff09\u3002\u5b83\u662f\u9632\u6b62\u6570\u636e\u5e93\u4e2d \u5b58\u5728\u4e0d\u7b26\u5408\u8bed\u4e49\u89c4\u5b9a\u7684\u6570\u636e\u548c\u9632\u6b62\u56e0\u9519\u8bef\u4fe1\u606f\u7684\u8f93\u5165\u8f93\u51fa\u9020\u6210\u65e0\u6548\u64cd\u4f5c\u6216\u9519\u8bef\u4fe1\u606f\u800c\u63d0\u51fa\u7684\u3002<\/p>\n\n\n\n<p>\u4e3a\u4e86\u4fdd\u8bc1\u6570\u636e\u7684\u5b8c\u6574\u6027\uff0cSQL\u89c4\u8303\u4ee5\u7ea6\u675f\u7684\u65b9\u5f0f\u5bf9\u8868\u6570\u636e\u8fdb\u884c\u989d\u5916\u7684\u6761\u4ef6\u9650\u5236\u3002\u4ece\u4ee5\u4e0b\u56db\u4e2a\u65b9\u9762\u8003\u8651\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5b9e\u4f53\u5b8c\u6574\u6027\uff08Entity Integrity\uff09 \uff1a\u4f8b\u5982\uff0c\u540c\u4e00\u4e2a\u8868\u4e2d\uff0c\u4e0d\u80fd\u5b58\u5728\u4e24\u6761\u5b8c\u5168\u76f8\u540c\u65e0\u6cd5\u533a\u5206\u7684\u8bb0\u5f55<\/li>\n\n\n\n<li>\u57df\u5b8c\u6574\u6027\uff08Domain Integrity\uff09 \uff1a\u4f8b\u5982\uff1a\u5e74\u9f84\u8303\u56f40-120\uff0c\u6027\u522b\u8303\u56f4\u201c\u7537\/\u5973\u201d<\/li>\n\n\n\n<li>\u5f15\u7528\u5b8c\u6574\u6027\uff08Referential Integrity\uff09 \uff1a\u4f8b\u5982\uff1a\u5458\u5de5\u6240\u5728\u90e8\u95e8\uff0c\u5728\u90e8\u95e8\u8868\u4e2d\u8981\u80fd\u627e\u5230\u8fd9\u4e2a\u90e8\u95e8<\/li>\n\n\n\n<li>\u7528\u6237\u81ea\u5b9a\u4e49\u5b8c\u6574\u6027\uff08User-defined Integrity\uff09 \uff1a\u4f8b\u5982\uff1a\u7528\u6237\u540d\u552f\u4e00\u3001\u5bc6\u7801\u4e0d\u80fd\u4e3a\u7a7a\u7b49\uff0c\u672c\u90e8\u95e8 \u7ecf\u7406\u7684\u5de5\u8d44\u4e0d\u5f97\u9ad8\u4e8e\u672c\u90e8\u95e8\u804c\u5de5\u7684\u5e73\u5747\u5de5\u8d44\u76845\u500d\u3002<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">\u4ec0\u4e48\u662f\u7ea6\u675f<\/h3>\n\n\n\n<p>\u7ea6\u675f\u662f\u8868\u7ea7\u7684\u5f3a\u5236\u89c4\u5b9a\u3002 \u53ef\u4ee5\u5728\u521b\u5efa\u8868\u65f6\u89c4\u5b9a\u7ea6\u675f\uff08\u901a\u8fc7 CREATE TABLE \u8bed\u53e5\uff09\uff0c\u6216\u8005\u5728\u8868\u521b\u5efa\u4e4b\u540e\u901a\u8fc7 ALTER TABLE \u8bed\u53e5\u89c4\u5b9a \u7ea6\u675f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>1.3 \u7ea6\u675f\u7684\u5206\u7c7b\uff1a\n\n\u89d2\u5ea61\uff1a\u7ea6\u675f\u7684\u5b57\u6bb5\u7684\u4e2a\u6570\n\u5355\u5217\u7ea6\u675f vs \u591a\u5217\u7ea6\u675f\n\n\u89d2\u5ea62\uff1a\u7ea6\u675f\u7684\u4f5c\u7528\u8303\u56f4\n\n\u5217\u7ea7\u7ea6\u675f\uff1a\u5c06\u6b64\u7ea6\u675f\u58f0\u660e\u5728\u5bf9\u5e94\u5b57\u6bb5\u7684\u540e\u9762\n\u8868\u7ea7\u7ea6\u675f\uff1a\u5728\u8868\u4e2d\u6240\u6709\u5b57\u6bb5\u90fd\u58f0\u660e\u5b8c\uff0c\u5728\u6240\u6709\u5b57\u6bb5\u7684\u540e\u9762\u58f0\u660e\u7684\u7ea6\u675f\n\n\u89d2\u5ea63\uff1a\u7ea6\u675f\u7684\u4f5c\u7528\uff08\u6216\u529f\u80fd\uff09\n\n\u2460 not null (\u975e\u7a7a\u7ea6\u675f)\n\u2461 unique  (\u552f\u4e00\u6027\u7ea6\u675f)\n\u2462 primary key (\u4e3b\u952e\u7ea6\u675f)\n\u2463 foreign key (\u5916\u952e\u7ea6\u675f)\n\u2464 check (\u68c0\u67e5\u7ea6\u675f)\n\u2465 default (\u9ed8\u8ba4\u503c\u7ea6\u675f)\n\n1.4 \u5982\u4f55\u6dfb\u52a0\/\u5220\u9664\u7ea6\u675f\uff1f\n\nCREATE TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\n\nALTER TABLE \u65f6\u589e\u52a0\u7ea6\u675f\u3001\u5220\u9664\u7ea6\u675f<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">2. \u975e\u7a7a\u7ea6\u675f<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">2.1 \u4f5c\u7528<\/h3>\n\n\n\n<p>\u9650\u5b9a\u67d0\u4e2a\u5b57\u6bb5\/\u67d0\u5217\u7684\u503c\u4e0d\u5141\u8bb8\u4e3a\u7a7a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#2. \u5982\u4f55\u67e5\u770b\u8868\u4e2d\u7684\u7ea6\u675f\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'test1';\n\nCREATE DATABASE dbtest13;\nUSE dbtest13;<\/code><\/pre>\n\n\n\n<p>\u5173\u952e\u5b57 NOT NULL<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9ed8\u8ba4\uff0c\u6240\u6709\u7684\u7c7b\u578b\u7684\u503c\u90fd\u53ef\u4ee5\u662fNULL\uff0c\u5305\u62ecINT\u3001FLOAT\u7b49\u6570\u636e\u7c7b\u578b<\/li>\n\n\n\n<li>\u975e\u7a7a\u7ea6\u675f\u53ea\u80fd\u51fa\u73b0\u5728\u8868\u5bf9\u8c61\u7684\u5217\u4e0a\uff0c\u53ea\u80fd\u67d0\u4e2a\u5217\u5355\u72ec\u9650\u5b9a\u975e\u7a7a\uff0c\u4e0d\u80fd\u7ec4\u5408\u975e\u7a7a<\/li>\n\n\n\n<li>\u4e00\u4e2a\u8868\u53ef\u4ee5\u6709\u5f88\u591a\u5217\u90fd\u5206\u522b\u9650\u5b9a\u4e86\u975e\u7a7a<\/li>\n\n\n\n<li>\u7a7a\u5b57\u7b26\u4e32''\u4e0d\u7b49\u4e8eNULL\uff0c0\u4e5f\u4e0d\u7b49\u4e8eNULL<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>#3. not null (\u975e\u7a7a\u7ea6\u675f)\n#3.1 \u5728CREATE TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\n\nCREATE TABLE test1(\nid INT NOT NULL,\nlast_name VARCHAR(15) NOT NULL,\nemail VARCHAR(25),\nsalary DECIMAL(10,2)\n\n);\n\nDESC test1;\n\nINSERT INTO test1(id,last_name,email,salary)\nVALUES(1,'Tom','tom@126.com',3400);\n\n#\u9519\u8bef\uff1aColumn 'last_name' cannot be null\nINSERT INTO test1(id,last_name,email,salary)\nVALUES(2,NULL,'tom1@126.com',3400);\n\n#\u9519\u8bef\uff1aColumn 'id' cannot be null\nINSERT INTO test1(id,last_name,email,salary)\nVALUES(NULL,'Jerry','jerry@126.com',3400);\n\nINSERT INTO test1(id,email)\nVALUES(2,'abc@126.com');\n\nUPDATE test1\nSET last_name = NULL\nWHERE id = 1;\n\nUPDATE test1\nSET email = 'tom@126.com'\nWHERE id = 1;\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>#3.2 \u5728ALTER TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\nSELECT * FROM test1;\n\nDESC test1;\n\nALTER TABLE test1         #\u5220\u9664\u975e\u7a7a\u7ea6\u675f\nMODIFY email VARCHAR(25) NOT NULL;\n\n\n#3.3 \u5728ALTER TABLE\u65f6\u5220\u9664\u7ea6\u675f\nALTER TABLE test1\nMODIFY email VARCHAR(25) NULL;\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">3. \u552f\u4e00\u6027\u7ea6\u675f<\/h2>\n\n\n\n<p>\u7528\u6765\u9650\u5236\u67d0\u4e2a\u5b57\u6bb5\/\u67d0\u5217\u7684\u503c\u4e0d\u80fd\u91cd\u590d\u3002\u552f\u4e00\u7ea6\u675f\uff0c\u5141\u8bb8\u51fa\u73b0\u591a\u4e2a\u7a7a\u503cNULL&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<\/p>\n\n\n\n<p>\u5173\u952e\u5b57 UNIQUE<\/p>\n\n\n\n<p>\u7279\u70b9<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u540c\u4e00\u4e2a\u8868\u53ef\u4ee5\u6709\u591a\u4e2a\u552f\u4e00\u7ea6\u675f\u3002<\/li>\n\n\n\n<li>\u552f\u4e00\u7ea6\u675f\u53ef\u4ee5\u662f\u67d0\u4e00\u4e2a\u5217\u7684\u503c\u552f\u4e00\uff0c\u4e5f\u53ef\u4ee5\u591a\u4e2a\u5217\u7ec4\u5408\u7684\u503c\u552f\u4e00\u3002<\/li>\n\n\n\n<li>\u552f\u4e00\u6027\u7ea6\u675f\u5141\u8bb8\u5217\u503c\u4e3a\u7a7a\u3002<\/li>\n\n\n\n<li><strong>\u5728\u521b\u5efa\u552f\u4e00\u7ea6\u675f\u7684\u65f6\u5019\uff0c\u5982\u679c\u4e0d\u7ed9\u552f\u4e00\u7ea6\u675f\u547d\u540d\uff0c\u5c31\u9ed8\u8ba4\u548c\u5217\u540d\u76f8\u540c<\/strong>\u3002<\/li>\n\n\n\n<li><strong>MySQL\u4f1a\u7ed9\u552f\u4e00\u7ea6\u675f\u7684\u5217\u4e0a\u9ed8\u8ba4\u521b\u5efa\u4e00\u4e2a\u552f\u4e00\u7d22\u5f15\u3002<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>#4. unique  (\u552f\u4e00\u6027\u7ea6\u675f)\n\n#4.1 \u5728CREATE TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\nCREATE TABLE test2(\nid INT UNIQUE, #\u5217\u7ea7\u7ea6\u675f\nlast_name VARCHAR(15) ,\nemail VARCHAR(25),\nsalary DECIMAL(10,2),\n#\u8868\u7ea7\u7ea6\u675f\nCONSTRAINT uk_test2_email UNIQUE(email)\n);\n\nDESC test2;\n\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'test2';\n\n#\u5728\u521b\u5efa\u552f\u4e00\u7ea6\u675f\u7684\u65f6\u5019\uff0c\u5982\u679c\u4e0d\u7ed9\u552f\u4e00\u7ea6\u675f\u547d\u540d\uff0c\u5c31\u9ed8\u8ba4\u548c\u5217\u540d\u76f8\u540c\u3002\n\nINSERT INTO test2(id,last_name,email,salary)\nVALUES(1,'Tom','tom@126.com',4500);\n\n#\u9519\u8bef\uff1aDuplicate entry '1' for key 'test2.id'\nINSERT INTO test2(id,last_name,email,salary)\nVALUES(1,'Tom1','tom1@126.com',4600);\n\n#\u9519\u8bef\uff1aDuplicate entry 'tom@126.com' for key 'test2.uk_test2_email'\nINSERT INTO test2(id,last_name,email,salary)\nVALUES(2,'Tom1','tom@126.com',4600);\n\n#\u53ef\u4ee5\u5411\u58f0\u660e\u4e3aunique\u7684\u5b57\u6bb5\u4e0a\u6dfb\u52a0null\u503c\u3002\u800c\u4e14\u53ef\u4ee5\u591a\u6b21\u6dfb\u52a0null\nINSERT INTO test2(id,last_name,email,salary)\nVALUES(2,'Tom1',NULL,4600);\n\nINSERT INTO test2(id,last_name,email,salary)\nVALUES(3,'Tom2',NULL,4600);\n\nSELECT * FROM test2;\n\n#\u5b57\u6bb5\u5217\u8868\u4e2d\u5982\u679c\u662f\u4e00\u4e2a\u5b57\u6bb5\uff0c\u8868\u793a\u8be5\u5217\u7684\u503c\u552f\u4e00\u3002\u5982\u679c\u662f\u4e24\u4e2a\u6216\u66f4\u591a\u4e2a\u5b57\u6bb5\uff0c\u90a3\u4e48\u590d\u5408\u552f\u4e00\uff0c\u5373\u591a\u4e2a\u5b57\u6bb5\u7684\u7ec4\u5408\u662f\u552f\u4e00\u7684\n#4.2 \u5728ALTER TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\n\nDESC test2;\n\nUPDATE test2\nSET salary = 5000\nWHERE id = 3;\n#\u65b9\u5f0f1\uff1a\nALTER TABLE test2\nADD CONSTRAINT uk_test2_sal UNIQUE(salary);\n#\u65b9\u5f0f2\uff1a\nALTER TABLE test2\nMODIFY last_name VARCHAR(15) UNIQUE;\n\n#4.3 \u590d\u5408\u7684\u552f\u4e00\u6027\u7ea6\u675f\nCREATE TABLE USER(\nid INT,\n`name` VARCHAR(15),\n`password` VARCHAR(25),\n\n#\u8868\u7ea7\u7ea6\u675f\nCONSTRAINT uk_user_name_pwd UNIQUE(`name`,`password`)\n);\n\nINSERT INTO USER\nVALUES(1,'Tom','abc');\n#\u53ef\u4ee5\u6210\u529f\u7684\uff1a\nINSERT INTO USER\nVALUES(1,'Tom1','abc');\n\nSELECT *\nFROM USER;\n\n#\u6848\u4f8b\uff1a\u590d\u5408\u7684\u552f\u4e00\u6027\u7ea6\u675f\u7684\u6848\u4f8b\n#\u5b66\u751f\u8868\nCREATE TABLE student(\n    sid INT,\t#\u5b66\u53f7\n    sname VARCHAR(20),\t#\u59d3\u540d\n    tel CHAR(11) UNIQUE KEY,  #\u7535\u8bdd\n    cardid CHAR(18) UNIQUE KEY #\u8eab\u4efd\u8bc1\u53f7\n);\n\n#\u8bfe\u7a0b\u8868\nCREATE TABLE course(\n    cid INT,  #\u8bfe\u7a0b\u7f16\u53f7\n    cname VARCHAR(20)     #\u8bfe\u7a0b\u540d\u79f0\n);\n\n#\u9009\u8bfe\u8868\nCREATE TABLE student_course(\n    id INT,\n    sid INT,  #\u5b66\u53f7\n    cid INT,  #\u8bfe\u7a0b\u7f16\u53f7\n    score INT,\n    UNIQUE KEY(sid,cid)  #\u590d\u5408\u552f\u4e00\n);\nINSERT INTO student VALUES(1,'\u5f20\u4e09','13710011002','101223199012015623');#\u6210\u529f\nINSERT INTO student VALUES(2,'\u674e\u56db','13710011003','101223199012015624');#\u6210\u529f\nINSERT INTO course VALUES(1001,'Java'),(1002,'MySQL');#\u6210\u529f\n\nSELECT * FROM student;\n\nSELECT * FROM course;\n\nINSERT INTO student_course VALUES\n(1, 1, 1001, 89),\n(2, 1, 1002, 90),\n(3, 2, 1001, 88),\n(4, 2, 1002, 56);#\u6210\u529f\n\nSELECT * FROM student_course;\n\n#\u9519\u8bef\uff1aDuplicate entry '2-1002' for key 'student_course.sid'\nINSERT INTO student_course VALUES\n(5,2,1002,67);\n\n#4.4 \u5220\u9664\u552f\u4e00\u6027\u7ea6\u675f\n-- \u6dfb\u52a0\u552f\u4e00\u6027\u7ea6\u675f\u7684\u5217\u4e0a\u4e5f\u4f1a\u81ea\u52a8\u521b\u5efa\u552f\u4e00\u7d22\u5f15\u3002\n-- \u5220\u9664\u552f\u4e00\u7ea6\u675f\u53ea\u80fd\u901a\u8fc7\u5220\u9664\u552f\u4e00\u7d22\u5f15\u7684\u65b9\u5f0f\u5220\u9664\u3002\n-- \u5220\u9664\u65f6\u9700\u8981\u6307\u5b9a\u552f\u4e00\u7d22\u5f15\u540d\uff0c\u552f\u4e00\u7d22\u5f15\u540d\u5c31\u548c\u552f\u4e00\u7ea6\u675f\u540d\u4e00\u6837\u3002\n-- \u5982\u679c\u521b\u5efa\u552f\u4e00\u7ea6\u675f\u65f6\u672a\u6307\u5b9a\u540d\u79f0\uff0c\u5982\u679c\u662f\u5355\u5217\uff0c\u5c31\u9ed8\u8ba4\u548c\u5217\u540d\u76f8\u540c\uff1b\u5982\u679c\u662f\u7ec4\u5408\u5217\uff0c\u90a3\u4e48\u9ed8\u8ba4\u548c()\u4e2d\u6392\u5728\u7b2c\u4e00\u4e2a\u7684\u5217\u540d\u76f8\u540c\u3002\u4e5f\u53ef\u4ee5\u81ea\u5b9a\u4e49\u552f\u4e00\u6027\u7ea6\u675f\u540d\u3002\n\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'student_course';\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'test2';\n\nDESC test2;\n\n#\u5982\u4f55\u5220\u9664\u552f\u4e00\u6027\u7d22\u5f15\nALTER TABLE test2\nDROP INDEX last_name;\n\nALTER TABLE test2\nDROP INDEX uk_test2_sal;\n\n#\u6ce8\u610f\uff1a\u53ef\u4ee5\u901a\u8fc7 show index from \u8868\u540d\u79f0; \u67e5\u770b\u8868\u7684\u7d22\u5f15<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">4. PRIMARY KEY \u7ea6\u675f<\/h2>\n\n\n\n<p>\u7528\u6765\u552f\u4e00\u6807\u8bc6\u8868\u4e2d\u7684\u4e00\u884c\u8bb0\u5f55\u3002\u5173\u952e\u5b57 \uff1aprimary key<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u00a0\u4e3b\u952e\u7ea6\u675f\u76f8\u5f53\u4e8e\u552f\u4e00\u7ea6\u675f+\u975e\u7a7a\u7ea6\u675f\u7684\u7ec4\u5408\uff0c\u4e3b\u952e\u7ea6\u675f\u5217\u4e0d\u5141\u8bb8\u91cd\u590d\uff0c\u4e5f\u4e0d\u5141\u8bb8\u51fa\u73b0\u7a7a\u503c\u3002<\/li>\n\n\n\n<li>\u4e00\u4e2a\u8868\u6700\u591a\u53ea\u80fd\u6709\u4e00\u4e2a\u4e3b\u952e\u7ea6\u675f\uff0c\u5efa\u7acb\u4e3b\u952e\u7ea6\u675f\u53ef\u4ee5\u5728\u5217\u7ea7\u522b\u521b\u5efa\uff0c\u4e5f\u53ef\u4ee5\u5728\u8868\u7ea7\u522b\u4e0a\u521b\u5efa\u3002<\/li>\n\n\n\n<li>\u4e3b\u952e\u7ea6\u675f\u5bf9\u5e94\u7740\u8868\u4e2d\u7684\u4e00\u5217\u6216\u8005\u591a\u5217\uff08\u590d\u5408\u4e3b\u952e\uff09<\/li>\n\n\n\n<li>\u5982\u679c\u662f\u591a\u5217\u7ec4\u5408\u7684\u590d\u5408\u4e3b\u952e\u7ea6\u675f\uff0c\u90a3\u4e48\u8fd9\u4e9b\u5217\u90fd\u4e0d\u5141\u8bb8\u4e3a\u7a7a\u503c\uff0c\u5e76\u4e14\u7ec4\u5408\u7684\u503c\u4e0d\u5141\u8bb8\u91cd\u590d\u3002<\/li>\n\n\n\n<li><strong>MySQL\u7684\u4e3b\u952e\u540d\u603b\u662fPRIMARY<\/strong>\uff0c\u5c31\u7b97\u81ea\u5df1\u547d\u540d\u4e86\u4e3b\u952e\u7ea6\u675f\u540d\u4e5f\u6ca1\u7528\u3002<\/li>\n\n\n\n<li>\u5f53\u521b\u5efa\u4e3b\u952e\u7ea6\u675f\u65f6\uff0c\u7cfb\u7edf\u9ed8\u8ba4\u4f1a\u5728\u6240\u5728\u7684\u5217\u6216\u5217\u7ec4\u5408\u4e0a\u5efa\u7acb\u5bf9\u5e94\u7684<strong>\u4e3b\u952e\u7d22\u5f15\uff08\u80fd\u591f\u6839\u636e\u4e3b\u952e\u67e5\u8be2 \u7684\uff0c\u5c31\u6839\u636e\u4e3b\u952e\u67e5\u8be2\uff0c\u6548\u7387\u66f4\u9ad8\uff09<\/strong>\u3002\u5982\u679c\u5220\u9664\u4e3b\u952e\u7ea6\u675f\u4e86\uff0c\u4e3b\u952e\u7ea6\u675f\u5bf9\u5e94\u7684\u7d22\u5f15\u5c31\u81ea\u52a8\u5220\u9664\u4e86\u3002<\/li>\n\n\n\n<li>\u9700\u8981\u6ce8\u610f\u7684\u4e00\u70b9\u662f\uff0c\u4e0d\u8981\u4fee\u6539\u4e3b\u952e\u5b57\u6bb5\u7684\u503c\u3002\u56e0\u4e3a\u4e3b\u952e\u662f\u6570\u636e\u8bb0\u5f55\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u5982\u679c\u4fee\u6539\u4e86\u4e3b\u952e\u7684 \u503c\uff0c\u5c31\u6709\u53ef\u80fd\u4f1a\u7834\u574f\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002\u00a0\u00a0<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>#5. primary key (\u4e3b\u952e\u7ea6\u675f)\n#5.1 \u5728CREATE TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\n\n#\u4e00\u4e2a\u8868\u4e2d\u6700\u591a\u53ea\u80fd\u6709\u4e00\u4e2a\u4e3b\u952e\u7ea6\u675f\u3002\n\n#\u9519\u8bef\uff1aMultiple primary key defined\nCREATE TABLE test3(\nid INT PRIMARY KEY, #\u5217\u7ea7\u7ea6\u675f\nlast_name VARCHAR(15) PRIMARY KEY,\nsalary DECIMAL(10,2),\nemail VARCHAR(25)\n);\n\n# \u4e3b\u952e\u7ea6\u675f\u7279\u5f81\uff1a\u975e\u7a7a\u4e14\u552f\u4e00\uff0c\u7528\u4e8e\u552f\u4e00\u7684\u6807\u8bc6\u8868\u4e2d\u7684\u4e00\u6761\u8bb0\u5f55\u3002\nCREATE TABLE test4(\nid INT PRIMARY KEY, #\u5217\u7ea7\u7ea6\u675f\nlast_name VARCHAR(15),\nsalary DECIMAL(10,2),\nemail VARCHAR(25)\n);\n\n#MySQL\u7684\u4e3b\u952e\u540d\u603b\u662fPRIMARY\uff0c\u5c31\u7b97\u81ea\u5df1\u547d\u540d\u4e86\u4e3b\u952e\u7ea6\u675f\u540d\u4e5f\u6ca1\u7528\u3002\nCREATE TABLE test5(\nid INT , \nlast_name VARCHAR(15),\nsalary DECIMAL(10,2),\nemail VARCHAR(25),\n#\u8868\u7ea7\u7ea6\u675f\nCONSTRAINT pk_test5_id PRIMARY KEY(id)  #\u6ca1\u6709\u5fc5\u8981\u8d77\u540d\u5b57\u3002\n);\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'test5';\n\nINSERT INTO test4(id,last_name,salary,email)\nVALUES(1,'Tom',4500,'tom@126.com');\n\n#\u9519\u8bef\uff1aDuplicate entry '1' for key 'test4.PRIMARY'\nINSERT INTO test4(id,last_name,salary,email)\nVALUES(1,'Tom',4500,'tom@126.com');\n\n#\u9519\u8bef\uff1aColumn 'id' cannot be null\nINSERT INTO test4(id,last_name,salary,email)\nVALUES(NULL,'Tom',4500,'tom@126.com');\n\nSELECT * FROM test4;\n\n\nCREATE TABLE user1(\nid INT,\nNAME VARCHAR(15),\nPASSWORD VARCHAR(25),\n\nPRIMARY KEY (NAME,PASSWORD)\n\n);\n#\u5982\u679c\u662f\u591a\u5217\u7ec4\u5408\u7684\u590d\u5408\u4e3b\u952e\u7ea6\u675f\uff0c\u90a3\u4e48\u8fd9\u4e9b\u5217\u90fd\u4e0d\u5141\u8bb8\u4e3a\u7a7a\u503c\uff0c\u5e76\u4e14\u7ec4\u5408\u7684\u503c\u4e0d\u5141\u8bb8\u91cd\u590d\u3002\nINSERT INTO user1\nVALUES(1,'Tom','abc');\n\nINSERT INTO user1\nVALUES(1,'Tom1','abc');\n#\u9519\u8bef\uff1aColumn 'name' cannot be null\nINSERT INTO user1\nVALUES(1,NULL,'abc');\n\nSELECT * FROM user1;\n\n#5.2 \u5728ALTER TABLE\u65f6\u6dfb\u52a0\u7ea6\u675f\n\nCREATE TABLE test6(\nid INT ,\nlast_name VARCHAR(15),\nsalary DECIMAL(10,2),\nemail VARCHAR(25)\n);\n\nDESC test6;\n\nALTER TABLE test6\nADD PRIMARY KEY (id);\n\n#5.3 \u5982\u4f55\u5220\u9664\u4e3b\u952e\u7ea6\u675f (\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\uff0c\u4e0d\u4f1a\u53bb\u5220\u9664\u8868\u4e2d\u7684\u4e3b\u952e\u7ea6\u675f\uff01)\nALTER TABLE test6\nDROP PRIMARY KEY;<\/code><\/pre>\n\n\n\n<p>\u8bf4\u660e\uff1a\u5220\u9664\u4e3b\u952e\u7ea6\u675f\uff0c\u4e0d\u9700\u8981\u6307\u5b9a\u4e3b\u952e\u540d\uff0c\u56e0\u4e3a\u4e00\u4e2a\u8868\u53ea\u6709\u4e00\u4e2a\u4e3b\u952e\uff0c\u5220\u9664\u4e3b\u952e\u7ea6\u675f\u540e\uff0c\u975e\u7a7a\u8fd8\u5b58 \u5728\u3002&nbsp;<\/p>\n\n\n\n<p>\u5176\u5b9e\u6211\u7ed9\u5927\u5bb6\u4e5f\u63d0\u5230\u4e86\uff0c\u5c31\u662f\u6211\u4eec\u8fd9\u4e2a\u4e3b\u952e\u7ea6\u675f\u54b1\u4eec\u58f0\u660e\u5728\u4e00\u4e2a\u5b57\u6bb5\u4e0a\uff0c\u6bd4\u5982\u8bf4i d\u4e0a\u4e86\uff0c\u90a3\u4e48\u6211\u4eec\u5c31\u4f1a\u5728\u8fd9\u4e2a\u5b57\u6bb5\u4e0a\u5462\u81ea\u52a8\u4f1a\u6dfb\u52a0\u4e00\u4e2a\u7ec4\u4ef6\u7684\u7d22\u5f15\uff0c\u800c\u6211\u4eec\u6574\u4e2a\u8fd9\u4e2a\u8868\u7684\u6570\u636e\u554a\uff0c\u5c31\u662f\u4f9d\u636e\u8fd9\u4e2a\u4e3b\u952e\u7d22\u5f15\u53bb\u6784\u5efa\u7684\u554a\uff0c\u5bf9\u5e94\u7684\u6570\u636e\u7ed3\u6784\u5462\u6211\u4eec\u53eb\u505ab\u52a0\u6570\uff0c\u5509\uff0c\u53eb\u505a\u8ffd\u52a0\u6570\uff0c\u4f60\u60f3\u60f3\u6211\u4eec\u5982\u679c\u8981\u662f\u628a\u4e3b\u5efa\u8fd9\u4e2a\u54ce\u7ed9\u5b83\u5e72\u6389\u4e86\uff0c\u4e0d\u8fd9\u4e2a\u7d22\u5f15\u5462\u4e5f\u5c31\u5e72\u6389\u4e86\uff0c\u90a3\u4e48\u63a5\u4e0b\u6765\u7684\u8bdd\u5462\u6211\u4eec\u8fd9\u4e2a\u8868\u57fa\u4e8e\u8fd9\u4e2a\u554ab\u52a0\u6570\u636e\u6784\u5efa\u7684\u4e00\u4e2a\u7279\u5f81\uff0c\u662f\u4e0d\u662f\u5c31\u88ab\u7834\u574f\u6389\u4e86\uff0c\u90a3\u6211\u4eec\u8fd9\u4e2a\u8868\u4f60\u540c\u5b66\u4f1a\u60f3\u8bf4\uff0c\u54ce\u8001\u5e08\uff0c\u90a3\u6211\u4eec\u539f\u6765\u6ca1\u6709\u8bb2\u8fd9\u4e2a\u4e3b\u4ef6\u7ea6\u675f\u7684\u65f6\u5019\u5462\uff0c\u8fd9\u4e2a\u8868\u4e5f\u6ca1\u89c1\u8bf4\u8fd9\u4e2a\u6709\u4e3b\u89c1\u5440\uff0c\u90a3\u90a3\u600e\u4e48\u529e\u554a\uff0c\u54ce\u90a3\u6211\u4eec\u8bf4\u8fd9\u4e2a\u7cfb\u7edf\u5462\uff0c\u54ce\u5b83\u4f1a\u81ea\u52a8\u7684\u7ed9\u6211\u4eec\u9009\u62e9\u4e00\u4e2a\u5b57\u6bb5\uff0c\u6bd4\u5982\u8bf4\u4f60\u8981\u4f18\u5148\u6709\u8fd9\u4e2a\u552f\u4e00\u6027\u7684\u8fd9\u4e2a\u7ea6\u675f\u7684\u8bdd\uff0c\u4ed6\u4f1a\u5148\u4f18\u5148\u9009\u90a3\u4e2a\u5fae\u4fe1\u7ea6\u675f\u90a3\u4e2a\u5b57\u6bb5\u4e86\uff0c\u4ed6\u53bb\u5e2e\u4f60\u6784\u5efa\u4e00\u4e2aab\u52a0\u6570\uff0c\u90a3\u4f60\u8981\u90fd\u6ca1\u6709\u7684\u8bdd\u5462\uff0c\u4ed6\u4f1a\u7ed9\u4f60\u9009\u62e9\u4e00\u4e2a\u76f8\u5bf9\u5408\u9002\u7684\u4e00\u4e2a\u5b57\u6bb5\u8fd8\u6709\u4f18\u5316\u5668\u5417\uff0c\u54ce\u53bb\u53bb\u6784\u5efa\uff0c\u90a3\u73b0\u5728\u7684\u8bdd\u5462\u5982\u679c\u4f60\u8981\u628a\u8fd9\u4e2a\u5e72\u6389\u4ee5\u540e\u5462\uff0c\u4ed6\u5c31\u770b\u8bf6\u4f60\u8981\u662f\u6709\u4e2a\u5b57\u6bb5\u5462\u662f\u4e00\u4e2a\u8bf6\u5fae\u578b\u7ea6\u675f\u7684\uff0c\u4ed6\u5c31\u62ff\u90a3\u4e2a\u8d44\u683c\u53bb\u6784\u5efa\u4e86\uff0c\u90a3\u539f\u6765\u8fd9\u4e2a\u6784\u5efa\u7684\u88ab\u52a0\u6570\u662f\u4e0d\u662f\u5c31\u5b8c\u5168\u5c31\u6ca1\u6709\u7528\u4e86\uff0c\u5509\u91cd\u65b0\u7684\u518d\u53bb\u6784\u5efa\uff0c\u90a3\u4f60\u8981\u8fd9\u4e2a\u8868\u4e2d\u8fbe\u5230\u51e0\u767e\u4e07\u6761\u4e0a\u5343\u4e07\u6761\u6570\u636e\u7684\u8bdd\u5462\uff0c\u4f60\u60f3\u60f3\u662f\u4e0d\u662f\u4e00\u4ef6\u975e\u5e38\u5d29\u6e83\u7684\u4e8b\u60c5\u554a\uff0c\u5c31\u5f88\u5d29\u6e83\u4e86\uff0c\u5c31\u597d\u6bd4\u662f\u5c31\u597d\u6bd4\u662f\u554a\uff0c\u8fd9\u4e2a\u79e6\u738b\u7684\u79e6\u8fd9\u4e2a\u539f\u6765\u79e6\u671d\u7684\u65f6\u5019\u5462\u5efa\u4e86\u4e00\u4e2a\u6b27\u7687\u5bab\u554a\uff0c\u867d\u7136\u8bf4\u8fd8\u6ca1\u6709\u5efa\u5b8c\u662f\u5427\uff0c\u7136\u540e\u540e\u6765\u5462\u4e00\u628a\u706b\u7ed9\u70e7\u6389\u4e86\uff0c\u662f\u4e0d\u662f\u6781\u5176\u7684\u53ef\u60dc\u554a\uff0c\u554a\u6ca1\u6709\u5fc5\u8981\u6211\u4eec\u518d\u53bb\u91cd\u65b0\u6784\u5efa\u4e00\u4e2a\u65b0\u7684b\u52a0\u6811\u554a\uff0c\u6240\u4ee5\u8bf4\u5462\u6211\u4eec\u5728\u5b9e\u9645\u5f00\u53d1\u5f53\u4e2d\uff0c\u54b1\u4eec\u8fd9\u4e2a\u4e3b\u952e\u7ea6\u675f\u554a\uff0c\u6ce8\u610f\u4e0d\u8981\u53bb\u6247\u5b83\u554a\uff0c\u54ce\u5343\u4e07\u4e0d\u8981\u53bb\u5220\u884c\uff0c\u90a3\u4e48\u5173\u4e8e\u4e3b\u952e\u7ea6\u675f\u5462\uff0c\u54b1\u4eec\u5c31\u8bf4\u5230\u8fd9\u513f\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">5. \u81ea\u589e\u5217\uff1aAUTO_INCREMENT<\/h2>\n\n\n\n<p>&nbsp;\u67d0\u4e2a\u5b57\u6bb5\u7684\u503c\u81ea\u589e \u5173\u952e\u5b57 auto_increment<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\uff081\uff09\u4e00\u4e2a\u8868\u6700\u591a\u53ea\u80fd\u6709\u4e00\u4e2a\u81ea\u589e\u957f\u5217<\/li>\n\n\n\n<li>\uff082\uff09\u5f53\u9700\u8981\u4ea7\u751f\u552f\u4e00\u6807\u8bc6\u7b26\u6216\u987a\u5e8f\u503c\u65f6\uff0c\u53ef\u8bbe\u7f6e\u81ea\u589e\u957f<\/li>\n\n\n\n<li>\uff083\uff09\u81ea\u589e\u957f\u5217\u7ea6\u675f\u7684\u5217\u5fc5\u987b\u662f\u952e\u5217\uff08\u4e3b\u952e\u5217\uff0c\u552f\u4e00\u952e\u5217\uff09<\/li>\n\n\n\n<li>\uff084\uff09\u81ea\u589e\u7ea6\u675f\u7684\u5217\u7684\u6570\u636e\u7c7b\u578b\u5fc5\u987b\u662f\u6574\u6570\u7c7b\u578b<\/li>\n\n\n\n<li>\uff085\uff09\u5982\u679c\u81ea\u589e\u5217\u6307\u5b9a\u4e86 0 \u548c null\uff0c\u4f1a\u5728\u5f53\u524d\u6700\u5927\u503c\u7684\u57fa\u7840\u4e0a\u81ea\u589e\uff1b\u5982\u679c\u81ea\u589e\u5217\u624b\u52a8\u6307\u5b9a\u4e86\u5177\u4f53\u503c\uff0c\u76f4\u63a5 \u8d4b\u503c\u4e3a\u5177\u4f53\u503c\u3002<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>#6. \u81ea\u589e\u957f\u5217:AUTO_INCREMENT\n# 6.1 \u5728CREATE TABLE\u65f6\u6dfb\u52a0\nCREATE TABLE test7(\nid INT PRIMARY KEY AUTO_INCREMENT,\nlast_name VARCHAR(15) \n);\n#\u5f00\u53d1\u4e2d\uff0c\u4e00\u65e6\u4e3b\u952e\u4f5c\u7528\u7684\u5b57\u6bb5\u4e0a\u58f0\u660e\u6709AUTO_INCREMENT\uff0c\u5219\u6211\u4eec\u5728\u6dfb\u52a0\u6570\u636e\u65f6\uff0c\u5c31\u4e0d\u8981\u7ed9\u4e3b\u952e\n#\u5bf9\u5e94\u7684\u5b57\u6bb5\u53bb\u8d4b\u503c\u4e86\u3002\nINSERT INTO test7(last_name)\nVALUES('Tom');\n\nSELECT * FROM test7;\n\n#\u5f53\u6211\u4eec\u5411\u4e3b\u952e\uff08\u542bAUTO_INCREMENT\uff09\u7684\u5b57\u6bb5\u4e0a\u6dfb\u52a00 \u6216 null\u65f6\uff0c\u5b9e\u9645\u4e0a\u4f1a\u81ea\u52a8\u7684\u5f80\u4e0a\u6dfb\u52a0\u6307\u5b9a\u7684\u5b57\u6bb5\u7684\u6570\u503c\nINSERT INTO test7(id,last_name)\nVALUES(0,'Tom');\n\nINSERT INTO test7(id,last_name)\nVALUES(NULL,'Tom');\n\nINSERT INTO test7(id,last_name)\nVALUES(10,'Tom');\n\nINSERT INTO test7(id,last_name)\nVALUES(-10,'Tom');\n\n#6.2 \u5728ALTER TABLE \u65f6\u6dfb\u52a0\nCREATE TABLE test8(\nid INT PRIMARY KEY ,\nlast_name VARCHAR(15) \n);\n\nDESC test8;\n\nALTER TABLE test8\nMODIFY id INT AUTO_INCREMENT;\n\n#6.3 \u5728ALTER TABLE \u65f6\u5220\u9664\n\nALTER TABLE test8\nMODIFY id INT ;\n\n#6.4 MySQL 8.0\u65b0\u7279\u6027\u2014\u81ea\u589e\u53d8\u91cf\u7684\u6301\u4e45\u5316\n\n#\u5728MySQL 5.7\u4e2d\u6f14\u793a\nCREATE TABLE test9(\nid INT PRIMARY KEY AUTO_INCREMENT\n);\n\nINSERT INTO test9\nVALUES(0),(0),(0),(0);\n\nSELECT * FROM test9;\n\nDELETE FROM test9\nWHERE id = 4;\n\nINSERT INTO test9\nVALUES(0);\n\nDELETE FROM test9\nWHERE id = 5;\n\n#\u91cd\u542f\u670d\u52a1\u5668\n\nSELECT * FROM test9;\n\nINSERT INTO test9\nVALUES(0);\n\n\n#\u5728MySQL 8.0\u4e2d\u6f14\u793a\nCREATE TABLE test9(\nid INT PRIMARY KEY AUTO_INCREMENT\n);\n\nINSERT INTO test9\nVALUES(0),(0),(0),(0);\n\nSELECT * FROM test9;\n\nDELETE FROM test9\nWHERE id = 4;\n\nINSERT INTO test9\nVALUES(0);\n\nDELETE FROM test9\nWHERE id = 5;\n\n#\u91cd\u542f\u670d\u52a1\u5668\n\nSELECT * FROM test9;\n\nINSERT INTO test9\nVALUES(0);<\/code><\/pre>\n\n\n\n<p>\u56e0\u4e3a\u552f\u4e00\u952e\uff0c\u548c\u4e3b\u952e\u662f\u901a\u8fc7\u5220\u9664\u552f\u4e00\u7d22\u5f15\u548c\u4e3b\u7d22\u5f15\u6765\u5220\u9664\u7684\uff0c\u6240\u6709\u7528\u7684\u662fdrop,\u800c\u4fee\u6539\u7c7b\u578b\u7528modify\uff0c\u8fd9\u6837\u8fd8\u662f\u597d\u5206\u6e05\u7684<br>modify\uff0c\u53ea\u6539\u53d8\u6570\u636e\u7c7b\u578b\uff0c\u4e5f\u53ef\u4ee5\u7528change\uff0c\u6539\u53d8\u5217\u540d\u7684\u540c\u65f6\u8f93\u5165\u65b0\u7684\u6570\u636e\u7c7b\u578b<\/p>\n\n\n\n<p>\u4f60\u7684\u7406\u89e3\u5927\u90e8\u5206\u662f\u6b63\u786e\u7684\uff0c\u4f46\u6709\u4e9b\u5730\u65b9\u9700\u8981\u8fdb\u4e00\u6b65\u6f84\u6e05\uff1a<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. <strong><code>DROP<\/code> \u7528\u4e8e\u5220\u9664\u4e3b\u952e\u3001\u552f\u4e00\u952e\u7b49\u7ea6\u675f<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e3b\u952e\uff08<code>PRIMARY KEY<\/code>\uff09\u548c\u552f\u4e00\u952e\uff08<code>UNIQUE<\/code>\uff09\u662f\u8868\u7684\u4e00\u79cd\u7ea6\u675f\uff0c\u8981\u5220\u9664\u8fd9\u4e9b\u7ea6\u675f\uff0c\u901a\u5e38\u9700\u8981\u4f7f\u7528 <code>DROP<\/code> \u3002<\/li>\n\n\n\n<li>\u4f8b\u5982\uff1a <code>-- \u5220\u9664\u4e3b\u952e ALTER TABLE table_name DROP PRIMARY KEY; -- \u5220\u9664\u552f\u4e00\u952e ALTER TABLE table_name DROP INDEX index_name;<\/code><img loading=\"lazy\" decoding=\"async\" height=\"15\" width=\"15\" src=\"blob:https:\/\/eve2333.top\/49ebaa80-23e6-4171-b8b7-212fb4124043\"><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. <strong><code>MODIFY<\/code> \u548c <code>CHANGE<\/code> \u7684\u533a\u522b<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>MODIFY<\/code><\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u53ea\u7528\u4e8e\u4fee\u6539\u5217\u7684 <strong>\u6570\u636e\u7c7b\u578b<\/strong>\uff0c\u800c\u4e0d\u6539\u53d8\u5217\u7684\u540d\u79f0\u3002<\/li>\n\n\n\n<li>\u4f8b\u5982\uff0c\u5c06\u5217 <code>age<\/code> \u7684\u6570\u636e\u7c7b\u578b\u4ece <code>INT<\/code> \u4fee\u6539\u4e3a <code>DECIMAL(5, 2)<\/code>\uff1a <code>ALTER TABLE table_name MODIFY age DECIMAL(5, 2);<\/code><img loading=\"lazy\" decoding=\"async\" height=\"15\" width=\"15\" src=\"blob:https:\/\/eve2333.top\/83d80792-52eb-42dd-8f35-79faa9bc3840\"><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong><code>CHANGE<\/code><\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u53ef\u4ee5\u540c\u65f6\u4fee\u6539\u5217\u7684 <strong>\u540d\u79f0<\/strong> \u548c <strong>\u6570\u636e\u7c7b\u578b<\/strong>\u3002<\/li>\n\n\n\n<li>\u4f8b\u5982\uff0c\u5c06\u5217 <code>old_name<\/code> \u6539\u540d\u4e3a <code>new_name<\/code>\uff0c\u5e76\u5c06\u5176\u6570\u636e\u7c7b\u578b\u4ece <code>INT<\/code> \u4fee\u6539\u4e3a <code>VARCHAR(50)<\/code>\uff1a <code>ALTER TABLE table_name CHANGE old_name new_name VARCHAR(50);<\/code><img loading=\"lazy\" decoding=\"async\" height=\"15\" width=\"15\" src=\"blob:https:\/\/eve2333.top\/b626eddf-9d36-423c-b743-091984a716ba\"><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. <strong>\u5173\u4e8e\u552f\u4e00\u952e\u548c\u4e3b\u952e\u7684\u5220\u9664<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f60\u7684\u8868\u8ff0\u4e2d\u63d0\u5230\u201c\u552f\u4e00\u952e\u548c\u4e3b\u952e\u662f\u901a\u8fc7\u5220\u9664\u552f\u4e00\u7d22\u5f15\u548c\u4e3b\u7d22\u5f15\u6765\u5220\u9664\u7684\u201d\uff0c\u8fd9\u4e2a\u8bf4\u6cd5\u6709\u4e9b\u4e0d\u592a\u51c6\u786e\u3002\u4e25\u683c\u6765\u8bf4\uff1a\n<ul class=\"wp-block-list\">\n<li>\u4e3b\u952e\u662f\u4e00\u4e2a\u7279\u6b8a\u7684\u552f\u4e00\u7d22\u5f15\uff0c\u5e76\u4e14\u7528\u4e8e\u6807\u8bc6\u8868\u4e2d\u7684\u6bcf\u4e00\u884c\u6570\u636e\u3002<\/li>\n\n\n\n<li>\u5220\u9664\u4e3b\u952e\u6216\u552f\u4e00\u952e\u901a\u5e38\u9700\u8981\u4f7f\u7528 SQL \u7684\u7279\u5b9a\u8bed\u6cd5\uff0c\u4f8b\u5982\uff1a <code>ALTER TABLE table_name DROP PRIMARY KEY; -- \u5220\u9664\u4e3b\u952e ALTER TABLE table_name DROP INDEX index_name; -- \u5220\u9664\u552f\u4e00\u952e<\/code><img loading=\"lazy\" decoding=\"async\" height=\"15\" width=\"15\" src=\"blob:https:\/\/eve2333.top\/5f6cdc1d-e737-4700-84fd-f54783b2059e\"><\/li>\n\n\n\n<li>\u8fd9\u91cc\u7684\u64cd\u4f5c\u5e76\u4e0d\u662f\u76f4\u63a5\u5220\u9664\u201c\u7d22\u5f15\u201d\uff0c\u800c\u662f\u5220\u9664\u4e86\u8fd9\u4e9b\u7ea6\u675f\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u603b\u7ed3<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>MODIFY<\/code><\/strong> \u7528\u4e8e\u4fee\u6539\u5217\u7684 <strong>\u6570\u636e\u7c7b\u578b<\/strong>\uff08\u4e0d\u6539\u53d8\u5217\u540d\uff09\u3002<\/li>\n\n\n\n<li><strong><code>CHANGE<\/code><\/strong> \u53ef\u4ee5\u4fee\u6539\u5217\u7684 <strong>\u540d\u79f0<\/strong> \u548c <strong>\u6570\u636e\u7c7b\u578b<\/strong>\u3002<\/li>\n\n\n\n<li><strong><code>DROP<\/code><\/strong> \u7528\u4e8e\u5220\u9664\u4e3b\u952e\u3001\u552f\u4e00\u952e\u7b49\u7ea6\u675f\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">&nbsp;5.6 MySQL 8.0\u65b0\u7279\u6027\u2014\u81ea\u589e\u53d8\u91cf\u7684\u6301\u4e45\u5316<\/h3>\n\n\n\n<p>\u5728MySQL 8.0\u4e4b\u524d\uff0c\u81ea\u589e\u4e3b\u952eAUTO_INCREMENT\u7684\u503c\u5982\u679c\u5927\u4e8emax(primary key)+1\uff0c\u5728MySQL\u91cd\u542f\u540e\uff0c\u4f1a\u91cd \u7f6eAUTO_INCREMENT=max(primary key)+1\uff0c\u8fd9\u79cd\u73b0\u8c61\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u4f1a\u5bfc\u81f4\u4e1a\u52a1\u4e3b\u952e\u51b2\u7a81\u6216\u8005\u5176\u4ed6\u96be\u4ee5\u53d1 \u73b0\u7684\u95ee\u9898\u3002 \u4e0b\u9762\u901a\u8fc7\u6848\u4f8b\u6765\u5bf9\u6bd4\u4e0d\u540c\u7684\u7248\u672c\u4e2d\u81ea\u589e\u53d8\u91cf\u662f\u5426\u6301\u4e45\u5316\u3002 \u5728MySQL 5.7\u7248\u672c\u4e2d\uff0c\u6d4b\u8bd5\u6b65\u9aa4\u5982 \u4e0b\uff1a \u521b\u5efa\u7684\u6570\u636e\u8868\u4e2d\u5305\u542b\u81ea\u589e\u4e3b\u952e\u7684id\u5b57\u6bb5\uff0c\u8bed\u53e5\u5982\u4e0b\uff1a<img loading=\"lazy\" decoding=\"async\" height=\"1082\" width=\"678\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/ca4a8f97f50d4775a0b618679cd89e4c.png\" alt=\"\"><\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"711\" width=\"681\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/d4e6a073e9d64bf3a674e2c821f9ddd2.png\" alt=\"\"><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">6. FOREIGN KEY \u7ea6\u675f<\/h2>\n\n\n\n<p><a href=\"https:\/\/www.bilibili.com\/video\/BV1iq4y1u7vj?spm_id_from=333.788.player.switch&amp;vd_source=b31958e33027799323b8b7d77ae181d4&amp;p=71\" target=\"_blank\"  rel=\"nofollow\" >71-\u5916\u952e\u7ea6\u675f\u7684\u4f7f\u7528_\u54d4\u54e9\u54d4\u54e9_bilibili<\/a><\/p>\n\n\n\n<p>\u4f5c\u7528 \u9650\u5b9a\u67d0\u4e2a\u8868\u7684\u67d0\u4e2a\u5b57\u6bb5\u7684\u5f15\u7528\u5b8c\u6574\u6027\u3002 \u6bd4\u5982\uff1a\u5458\u5de5\u8868\u7684\u5458\u5de5\u6240\u5728\u90e8\u95e8\u7684\u9009\u62e9\uff0c\u5fc5\u987b\u5728\u90e8\u95e8\u8868\u80fd\u627e\u5230\u5bf9\u5e94\u7684\u90e8\u5206\u3002<strong>\u5f00\u53d1\u4e2d\u57fa\u672c\u4e0d\u4f7f\u7528\u5916\u952e<\/strong><\/p>\n\n\n\n<p>&nbsp;\u5173\u952e\u5b57 FOREIGN KEY<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6.3 \u4e3b\u8868\u548c\u4ece\u8868\/\u7236\u8868\u548c\u5b50\u8868<\/h3>\n\n\n\n<p>\u4e3b\u8868\uff08\u7236\u8868\uff09\uff1a\u88ab\u5f15\u7528\u7684\u8868\uff0c\u88ab\u53c2\u8003\u7684\u8868 \u4ece\u8868\uff08\u5b50\u8868\uff09\uff1a\u5f15\u7528\u522b\u4eba\u7684\u8868\uff0c\u53c2\u8003\u522b\u4eba\u7684\u8868<\/p>\n\n\n\n<p>\u4f8b\u5982\uff1a\u5458\u5de5\u8868\u7684\u5458\u5de5\u6240\u5728\u90e8\u95e8\u8fd9\u4e2a\u5b57\u6bb5\u7684\u503c\u8981\u53c2\u8003\u90e8\u95e8\u8868\uff1a\u90e8\u95e8\u8868\u662f\u4e3b\u8868\uff0c\u5458\u5de5\u8868\u662f\u4ece\u8868\u3002<br>\u4f8b\u5982\uff1a\u5b66\u751f\u8868\u3001\u8bfe\u7a0b\u8868\u3001\u9009\u8bfe\u8868\uff1a\u9009\u8bfe\u8868\u7684\u5b66\u751f\u548c\u8bfe\u7a0b\u8981\u5206\u522b\u53c2\u8003\u5b66\u751f\u8868\u548c\u8bfe\u7a0b\u8868\uff0c\u5b66\u751f\u8868\u548c\u8bfe\u7a0b\u8868\u662f\u4e3b\u8868\uff0c\u9009\u8bfe\u8868\u662f\u4ece\u8868\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\uff081\uff09\u4ece\u8868\u7684\u5916\u952e\u5217\uff0c\u5fc5\u987b\u5f15\u7528\/\u53c2\u8003\u4e3b\u8868\u7684\u4e3b\u952e\u6216\u552f\u4e00\u7ea6\u675f\u7684\u5217 \u4e3a\u4ec0\u4e48\uff1f\u56e0\u4e3a\u88ab\u4f9d\u8d56\/\u88ab\u53c2\u8003\u7684\u503c\u5fc5\u987b\u662f\u552f\u4e00\u7684<\/li>\n\n\n\n<li>\uff082\uff09\u5728\u521b\u5efa\u5916\u952e\u7ea6\u675f\u65f6\uff0c\u5982\u679c\u4e0d\u7ed9\u5916\u952e\u7ea6\u675f\u547d\u540d\uff0c\u9ed8\u8ba4\u540d\u4e0d\u662f\u5217\u540d\uff0c\u800c\u662f\u81ea\u52a8\u4ea7\u751f\u4e00\u4e2a\u5916\u952e\u540d\uff08\u4f8b\u5982 student_ibfk_1;\uff09\uff0c\u4e5f\u53ef\u4ee5\u6307\u5b9a\u5916\u952e\u7ea6\u675f\u540d\u3002<\/li>\n\n\n\n<li>\uff083\uff09\u521b\u5efa(CREATE)\u8868\u65f6\u5c31\u6307\u5b9a\u5916\u952e\u7ea6\u675f\u7684\u8bdd\uff0c\u5148\u521b\u5efa\u4e3b\u8868\uff0c\u518d\u521b\u5efa\u4ece\u8868<\/li>\n\n\n\n<li>\uff084\uff09\u5220\u8868\u65f6\uff0c\u5148\u5220\u4ece\u8868\uff08\u6216\u5148\u5220\u9664\u5916\u952e\u7ea6\u675f\uff09\uff0c\u518d\u5220\u9664\u4e3b\u8868<\/li>\n\n\n\n<li>\uff085\uff09\u5f53\u4e3b\u8868\u7684\u8bb0\u5f55\u88ab\u4ece\u8868\u53c2\u7167\u65f6\uff0c\u4e3b\u8868\u7684\u8bb0\u5f55\u5c06\u4e0d\u5141\u8bb8\u5220\u9664\uff0c\u5982\u679c\u8981\u5220\u9664\u6570\u636e\uff0c\u9700\u8981\u5148\u5220\u9664\u4ece\u8868\u4e2d\u4f9d\u8d56 \u8be5\u8bb0\u5f55\u7684\u6570\u636e\uff0c\u7136\u540e\u624d\u53ef\u4ee5\u5220\u9664\u4e3b\u8868\u7684\u6570\u636e<\/li>\n\n\n\n<li>\uff086\uff09\u5728\u201c\u4ece\u8868\u201d\u4e2d\u6307\u5b9a\u5916\u952e\u7ea6\u675f\uff0c\u5e76\u4e14\u4e00\u4e2a\u8868\u53ef\u4ee5\u5efa\u7acb\u591a\u4e2a\u5916\u952e\u7ea6\u675f<\/li>\n\n\n\n<li>\uff087\uff09\u4ece\u8868\u7684\u5916\u952e\u5217\u4e0e\u4e3b\u8868\u88ab\u53c2\u7167\u7684\u5217\u540d\u5b57\u53ef\u4ee5\u4e0d\u76f8\u540c\uff0c\u4f46\u662f\u6570\u636e\u7c7b\u578b\u5fc5\u987b\u4e00\u6837\uff0c\u903b\u8f91\u610f\u4e49\u4e00\u81f4\u3002\u5982\u679c\u7c7b \u578b\u4e0d\u4e00\u6837\uff0c\u521b\u5efa\u5b50\u8868\u65f6\uff0c\u5c31\u4f1a\u51fa\u73b0\u9519\u8bef\u201cERROR 1005 (HY000): Can't create table'database.tablename'(errno: 150)\u201d\u3002 \u4f8b\u5982\uff1a\u90fd\u662f\u8868\u793a\u90e8\u95e8\u7f16\u53f7\uff0c\u90fd\u662fint\u7c7b\u578b\u3002<\/li>\n\n\n\n<li>\uff088\uff09<strong>\u5f53\u521b\u5efa\u5916\u952e\u7ea6\u675f\u65f6\uff0c\u7cfb\u7edf\u9ed8\u8ba4\u4f1a\u5728\u6240\u5728\u7684\u5217\u4e0a\u5efa\u7acb\u5bf9\u5e94\u7684\u666e\u901a\u7d22\u5f15\u3002\u4f46\u662f\u7d22\u5f15\u540d\u662f\u5916\u952e\u7684\u7ea6\u675f \u540d\u3002\uff08\u6839\u636e\u5916\u952e\u67e5\u8be2\u6548\u7387\u5f88\u9ad8\uff09<\/strong><\/li>\n\n\n\n<li>\uff089\uff09\u5220\u9664\u5916\u952e\u7ea6\u675f\u540e\uff0c\u5fc5\u987b\u624b\u52a8\u5220\u9664\u5bf9\u5e94\u7684\u7d22\u5f15<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>#7.foreign key (\u5916\u952e\u7ea6\u675f)\n#7.1 \u5728CREATE TABLE \u65f6\u6dfb\u52a0\n\n#\u4e3b\u8868\u548c\u4ece\u8868\uff1b\u7236\u8868\u548c\u5b50\u8868\n\n#\u2460\u5148\u521b\u5efa\u4e3b\u8868\nCREATE TABLE dept1(\ndept_id INT,\ndept_name VARCHAR(15)\n);\n#\u2461\u518d\u521b\u5efa\u4ece\u8868\nCREATE TABLE emp1(\nemp_id INT PRIMARY KEY AUTO_INCREMENT,\nemp_name VARCHAR(15),\ndepartment_id INT,\n\n#\u8868\u7ea7\u7ea6\u675f\nCONSTRAINT fk_emp1_dept_id FOREIGN KEY (department_id) REFERENCES dept1(dept_id)\n\n);\n\n#\u4e0a\u8ff0\u64cd\u4f5c\u62a5\u9519\uff0c\u56e0\u4e3a\u4e3b\u8868\u4e2d\u7684dept_id\u4e0a\u6ca1\u6709\u4e3b\u952e\u7ea6\u675f\u6216\u552f\u4e00\u6027\u7ea6\u675f\u3002\n#\u2462 \u6dfb\u52a0\nALTER TABLE dept1\nADD PRIMARY KEY (dept_id);\n\nDESC dept1;\n\n#\u2463 \u518d\u521b\u5efa\u4ece\u8868\nCREATE TABLE emp1(\nemp_id INT PRIMARY KEY AUTO_INCREMENT,\nemp_name VARCHAR(15),\ndepartment_id INT,\n\n#\u8868\u7ea7\u7ea6\u675f\nCONSTRAINT fk_emp1_dept_id FOREIGN KEY (department_id) REFERENCES dept1(dept_id)\n\n);\n\nDESC emp1;\n\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'emp1';\n\n#7.2 \u6f14\u793a\u5916\u952e\u7684\u6548\u679c\n#\u6dfb\u52a0\u5931\u8d25\nINSERT INTO emp1\nVALUES(1001,'Tom',10);\n\n#\nINSERT INTO dept1\nVALUES(10,'IT');\n#\u5728\u4e3b\u8868dept1\u4e2d\u6dfb\u52a0\u4e8610\u53f7\u90e8\u95e8\u4ee5\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5728\u4ece\u8868\u4e2d\u6dfb\u52a010\u53f7\u90e8\u95e8\u7684\u5458\u5de5\nINSERT INTO emp1\nVALUES(1001,'Tom',10);\n\n#\u5220\u9664\u5931\u8d25\nDELETE FROM dept1\nWHERE dept_id = 10;\n\n#\u66f4\u65b0\u5931\u8d25\nUPDATE dept1\nSET dept_id = 20\nWHERE dept_id = 10;\n\n#7.3 \u5728ALTER TABLE\u65f6\u6dfb\u52a0\u5916\u952e\u7ea6\u675f\nCREATE TABLE dept2(\ndept_id INT PRIMARY KEY,\ndept_name VARCHAR(15)\n);\n\nCREATE TABLE emp2(\nemp_id INT PRIMARY KEY AUTO_INCREMENT,\nemp_name VARCHAR(15),\ndepartment_id INT\n);\n\nALTER TABLE emp2\nADD CONSTRAINT fk_emp2_dept_id FOREIGN KEY(department_id) REFERENCES dept2(dept_id);\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'emp2';\n\n#7.4 ###  \u7ea6\u675f\u7b49\u7ea7\n\n-- `Cascade\u65b9\u5f0f`\uff1a\u5728\u7236\u8868\u4e0aupdate\/delete\u8bb0\u5f55\u65f6\uff0c\u540c\u6b65update\/delete\u6389\u5b50\u8868\u7684\u5339\u914d\u8bb0\u5f55 \n\n-- `Set null\u65b9\u5f0f`\uff1a\u5728\u7236\u8868\u4e0aupdate\/delete\u8bb0\u5f55\u65f6\uff0c\u5c06\u5b50\u8868\u4e0a\u5339\u914d\u8bb0\u5f55\u7684\u5217\u8bbe\u4e3anull\uff0c\u4f46\u662f\u8981\u6ce8\u610f\u5b50\u8868\u7684\u5916\u952e\u5217\u4e0d\u80fd\u4e3anot null  \n\n-- `No action\u65b9\u5f0f`\uff1a\u5982\u679c\u5b50\u8868\u4e2d\u6709\u5339\u914d\u7684\u8bb0\u5f55\uff0c\u5219\u4e0d\u5141\u8bb8\u5bf9\u7236\u8868\u5bf9\u5e94\u5019\u9009\u952e\u8fdb\u884cupdate\/delete\u64cd\u4f5c  \n\n-- `Restrict\u65b9\u5f0f`\uff1a\u540cno action\uff0c \u90fd\u662f\u7acb\u5373\u68c0\u67e5\u5916\u952e\u7ea6\u675f\n\n-- `Set default\u65b9\u5f0f`\uff08\u5728\u53ef\u89c6\u5316\u5de5\u5177SQLyog\u4e2d\u53ef\u80fd\u663e\u793a\u7a7a\u767d\uff09\uff1a\u7236\u8868\u6709\u53d8\u66f4\u65f6\uff0c\u5b50\u8868\u5c06\u5916\u952e\u5217\u8bbe\u7f6e\u6210\u4e00\u4e2a\u9ed8\u8ba4\u7684\u503c\uff0c\u4f46Innodb\u4e0d\u80fd\u8bc6\u522b\n\n#\u6f14\u793a\uff1a\n# on update cascade on delete set null\nCREATE TABLE dept(\n    did INT PRIMARY KEY,\t\t#\u90e8\u95e8\u7f16\u53f7\n    dname VARCHAR(50)\t\t\t#\u90e8\u95e8\u540d\u79f0\n);\n\nCREATE TABLE emp(\n    eid INT PRIMARY KEY,  #\u5458\u5de5\u7f16\u53f7\n    ename VARCHAR(5),     #\u5458\u5de5\u59d3\u540d\n    deptid INT,\t\t  #\u5458\u5de5\u6240\u5728\u7684\u90e8\u95e8\n    FOREIGN KEY (deptid) REFERENCES dept(did)  ON UPDATE CASCADE ON DELETE SET NULL\n    #\u628a\u4fee\u6539\u64cd\u4f5c\u8bbe\u7f6e\u4e3a\u7ea7\u8054\u4fee\u6539\u7b49\u7ea7\uff0c\u628a\u5220\u9664\u64cd\u4f5c\u8bbe\u7f6e\u4e3aset null\u7b49\u7ea7\n);\n\nINSERT INTO dept VALUES(1001,'\u6559\u5b66\u90e8');\nINSERT INTO dept VALUES(1002, '\u8d22\u52a1\u90e8');\nINSERT INTO dept VALUES(1003, '\u54a8\u8be2\u90e8');\n\n\nINSERT INTO emp VALUES(1,'\u5f20\u4e09',1001); #\u5728\u6dfb\u52a0\u8fd9\u6761\u8bb0\u5f55\u65f6\uff0c\u8981\u6c42\u90e8\u95e8\u8868\u67091001\u90e8\u95e8\nINSERT INTO emp VALUES(2,'\u674e\u56db',1001);\nINSERT INTO emp VALUES(3,'\u738b\u4e94',1002);\n\n\nUPDATE dept\nSET did = 1004\nWHERE did = 1002;\n\nDELETE FROM dept\nWHERE did = 1004;\n\n\nSELECT * FROM dept;\n\nSELECT * FROM emp;\n\n#\u7ed3\u8bba\uff1a\u5bf9\u4e8e\u5916\u952e\u7ea6\u675f\uff0c\u6700\u597d\u662f\u91c7\u7528: `ON UPDATE CASCADE ON DELETE RESTRICT` \u7684\u65b9\u5f0f\u3002\n\n\n#7.5 \u5220\u9664\u5916\u952e\u7ea6\u675f\n\n#\u4e00\u4e2a\u8868\u4e2d\u53ef\u4ee5\u58f0\u660e\u6709\u591a\u4e2a\u5916\u952e\u7ea6\u675f\nUSE atguigudb;\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'employees';\n\nUSE dbtest13;\n\nSELECT * FROM information_schema.table_constraints \nWHERE table_name = 'emp1';\n\n#\u5220\u9664\u5916\u952e\u7ea6\u675f\n\nALTER TABLE emp1\nDROP FOREIGN KEY fk_emp1_dept_id;\n\n#\u518d\u624b\u52a8\u7684\u5220\u9664\u5916\u952e\u7ea6\u675f\u5bf9\u5e94\u7684\u666e\u901a\u7d22\u5f15\nSHOW INDEX FROM emp1;\n\nALTER TABLE emp1\nDROP INDEX fk_emp1_dept_id;<\/code><\/pre>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"1132\" width=\"717\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/6873c2085b6c4f529f70e48741a5586d.png\" alt=\"\"><img loading=\"lazy\" decoding=\"async\" height=\"1086\" width=\"724\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/ac8fc058455e41b18fa9a00324a4ae29.png\" alt=\"\"><img loading=\"lazy\" decoding=\"async\" height=\"1209\" width=\"730\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/6b89bdb61c5e43ac92176a4a51306d81.png\" alt=\"\"><img loading=\"lazy\" decoding=\"async\" height=\"1236\" width=\"716\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/9b25496192bd428c9843ed5dd5a90a2c.png\" alt=\"\"><img loading=\"lazy\" decoding=\"async\" height=\"1269\" width=\"704\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/ec8a50a400394c4b809a7edd6ca1fcc4.png\" alt=\"\"><img loading=\"lazy\" decoding=\"async\" height=\"1247\" width=\"712\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/bc04b2689b3d4fcfb9fecbc75cd482e1.png\" alt=\"\"><\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"1177\" width=\"723\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/d99847ed2c234dbba003da081d67c798.png\" alt=\"\"><\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"1255\" width=\"722\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/3bb53716f99f40e38a9fcc967c69497c.png\" alt=\"\"><\/p>\n\n\n\n<p><img loading=\"lazy\" decoding=\"async\" height=\"1250\" width=\"809\" src=\"https:\/\/i-blog.csdnimg.cn\/direct\/b05b7c11d3b44a279d144f8bcd443976.png\" alt=\"\">\u200b<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6.9 \u5f00\u53d1\u573a\u666f<\/h3>\n\n\n\n<p>\u95ee\u98981\uff1a\u5982\u679c\u4e24\u4e2a\u8868\u4e4b\u95f4\u6709\u5173\u7cfb\uff08\u4e00\u5bf9\u4e00\u3001\u4e00\u5bf9\u591a\uff09\uff0c\u6bd4\u5982\uff1a\u5458\u5de5\u8868\u548c\u90e8\u95e8\u8868\uff08\u4e00\u5bf9\u591a\uff09\uff0c\u5b83\u4eec\u4e4b\u95f4\u662f\u5426\u4e00\u5b9a\u8981\u5efa\u5916\u952e\u7ea6\u675f\uff1f<br>\u7b54\uff1a\u4e0d\u662f\u7684<\/p>\n\n\n\n<p>\u95ee\u98982\uff1a\u5efa\u548c\u4e0d\u5efa\u5916\u952e\u7ea6\u675f\u6709\u4ec0\u4e48\u533a\u522b\uff1f<br>\u7b54\uff1a\u5efa\u5916\u952e\u7ea6\u675f\uff0c\u4f60\u7684\u64cd\u4f5c\uff08\u521b\u5efa\u8868\u3001\u5220\u9664\u8868\u3001\u6dfb\u52a0\u3001\u4fee\u6539\u3001\u5220\u9664\uff09\u4f1a\u53d7\u5230\u9650\u5236\uff0c\u4ece\u8bed\u6cd5\u5c42\u9762\u53d7\u5230\u9650\u5236\u3002\u4f8b\u5982\uff1a\u5728\u5458\u5de5\u8868\u4e2d\u4e0d\u53ef\u80fd\u6dfb\u52a0\u4e00\u4e2a\u5458\u5de5\u4fe1\u606f\uff0c\u5b83\u7684\u90e8\u95e8\u7684\u503c\u5728\u90e8\u95e8\u8868\u4e2d\u627e\u4e0d\u5230\u3002<br>\u4e0d\u5efa\u5916\u952e\u7ea6\u675f\uff0c\u4f60\u7684\u64cd\u4f5c\uff08\u521b\u5efa\u8868\u3001\u5220\u9664\u8868\u3001\u6dfb\u52a0\u3001\u4fee\u6539\u3001\u5220\u9664\uff09\u4e0d\u53d7\u9650\u5236\uff0c\u8981\u4fdd\u8bc1\u6570\u636e\u7684\u5f15\u7528\u5b8c\u6574\u6027\uff0c\u53ea\u80fd\u4f9d\u9760\u7a0b\u5e8f\u5458\u7684\u81ea\u89c9\uff0c\u6216\u8005\u662f\u5728Java\u7a0b\u5e8f\u4e2d\u8fdb\u884c\u9650\u5b9a\u3002\u4f8b\u5982\uff1a\u5728\u5458\u5de5\u8868\u4e2d\uff0c\u53ef\u4ee5\u6dfb\u52a0\u4e00\u4e2a\u5458\u5de5\u7684\u4fe1\u606f\uff0c\u5b83\u7684\u90e8\u95e8\u6307\u5b9a\u4e3a\u4e00\u4e2a\u5b8c\u5168\u4e0d\u5b58\u5728\u90e8\u95e8\u3002<\/p>\n\n\n\n<p>\u95ee\u98983\uff1a\u90a3\u4e48\u5efa\u548c\u4e0d\u5efa\u5916\u952e\u7ea6\u675f\u548c\u67e5\u8be2\u6709\u6ca1\u6709\u5173\u7cfb\uff1f<br>\u7b54\uff1a\u6ca1\u6709<\/p>\n\n\n\n<p>\u5728MySQL\u91cc\uff0c\u5916\u952e\u7ea6\u675f\u662f\u6709\u6210\u672c\u7684\uff0c\u9700\u8981\u6d88\u8017\u7cfb\u7edf\u8d44\u6e90\u3002\u5bf9\u4e8e\u5927\u5e76\u53d1\u7684SQL\u64cd\u4f5c\uff0c\u6709\u53ef\u80fd\u4f1a\u4e0d\u9002\u5408\u3002\u6bd4\u5982\u5927\u578b\u7f51\u7ad9\u7684\u4e2d\u592e\u6570\u636e\u5e93\uff0c\u53ef\u80fd\u4f1a\u56e0\u4e3a\u5916\u952e\u7ea6\u675f\u7684\u7cfb\u7edf\u5f00\u9500\u800c\u53d8\u5f97\u975e\u5e38\u6162\u3002\u6240\u4ee5\uff0cMySQL\u5141\u8bb8\u4f60\u4e0d\u4f7f\u7528\u7cfb\u7edf\u81ea\u5e26\u7684\u5916\u952e\u7ea6\u675f\uff0c\u5728\u5e94\u7528\u5c42\u9762\u5b8c\u6210\u68c0\u67e5\u6570\u636e\u4e00\u81f4\u6027\u7684\u903b\u8f91\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5373\u4f7f\u4f60\u4e0d\u7528\u5916\u952e\u7ea6\u675f\uff0c\u4e5f\u8981\u60f3\u529e\u6cd5\u901a\u8fc7\u5e94\u7528\u5c42\u9762\u7684\u9644\u52a0\u903b\u8f91\uff0c\u6765\u5b9e\u73b0\u5916\u952e\u7ea6\u675f\u7684\u529f\u80fd\uff0c\u786e\u4fdd\u6570\u636e\u7684\u4e00\u81f4\u6027\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6.10 \u963f\u91cc\u5f00\u53d1\u89c4\u8303<\/h3>\n\n\n\n<p>\u3010\u5f3a\u5236\u3011\u4e0d\u5f97\u4f7f\u7528\u5916\u952e\u4e0e\u7ea7\u8054\uff0c\u4e00\u5207\u5916\u952e\u6982\u5ff5\u5fc5\u987b\u5728\u5e94\u7528\u5c42\u89e3\u51b3\u3002<br>\u8bf4\u660e\uff1a\uff08\u6982\u5ff5\u89e3\u91ca\uff09\u5b66\u751f\u8868\u4e2d\u7684student_id\u662f\u4e3b\u952e\uff0c\u90a3\u4e48\u6210\u7ee9\u8868\u4e2d\u7684student_id\u5219\u4e3a\u5916\u952e\u3002\u5982\u679c\u66f4\u65b0\u5b66\u751f\u8868\u4e2d\u7684student_id\uff0c\u540c\u65f6\u89e6\u53d1\u6210\u7ee9\u8868\u4e2d\u7684student_id\u66f4\u65b0\uff0c\u5373\u4e3a\u7ea7\u8054\u66f4\u65b0\u3002\u5916\u952e\u4e0e\u7ea7\u8054\u66f4\u65b0\u9002\u7528\u4e8e\u5355\u673a\u4f4e\u5e76\u53d1\uff0c\u4e0d\u9002\u5408\u5206\u5e03\u5f0f\u3001\u9ad8\u5e76\u53d1\u96c6\u7fa4\uff1b\u7ea7\u8054\u66f4\u65b0\u662f\u5f3a\u963b\u585e\uff0c\u5b58\u5728\u6570\u636e\u5e93\u66f4\u65b0\u98ce\u66b4\u7684\u98ce\u9669\uff1b\u5916\u952e\u5f71\u54cd\u6570\u636e\u5e93\u7684\u63d2\u5165\u901f\u5ea6\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">&nbsp;7. CHECK \u7ea6\u675f<\/h2>\n\n\n\n<p>\u4f5c\u7528 \u68c0\u67e5\u67d0\u4e2a\u5b57\u6bb5\u7684\u503c\u662f\u5426\u7b26\u53f7xx\u8981\u6c42\uff0c\u4e00\u822c\u6307\u7684\u662f\u503c\u7684\u8303\u56f4<\/p>\n\n\n\n<p>\u5173\u952e\u5b57 CHECK<\/p>\n\n\n\n<p>\u8bf4\u660e\uff1aMySQL 5.7 \u4e0d\u652f\u6301 MySQL5.7 \u53ef\u4ee5\u4f7f\u7528check\u7ea6\u675f\uff0c\u4f46check\u7ea6\u675f\u5bf9\u6570\u636e\u9a8c\u8bc1\u6ca1\u6709\u4efb\u4f55\u4f5c\u7528\u3002\u6dfb\u52a0\u6570\u636e\u65f6\uff0c\u6ca1\u6709\u4efb\u4f55\u9519\u8bef\u6216\u8b66\u544a \u4f46\u662fMySQL 8.0\u4e2d\u53ef\u4ee5\u4f7f\u7528check\u7ea6\u675f\u4e86\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#8. check \u7ea6\u675f\n# MySQL5.7 \u4e0d\u652f\u6301CHECK\u7ea6\u675f\uff0cMySQL8.0\u652f\u6301CHECK\u7ea6\u675f\u3002\n\nCREATE TABLE test10(\nid INT,\nlast_name VARCHAR(15),\nsalary DECIMAL(10,2) CHECK(salary &gt; 2000)\n);\n\nINSERT INTO test10\nVALUES(1,'Tom',2500);\n\n#\u6dfb\u52a0\u5931\u8d25\nINSERT INTO test10\nVALUES(2,'Tom1',1500);\n\nSELECT * FROM test10;<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">8. DEFAULT\u7ea6\u675f<\/h2>\n\n\n\n<p>\u4f5c\u7528 \u7ed9\u67d0\u4e2a\u5b57\u6bb5\/\u67d0\u5217\u6307\u5b9a\u9ed8\u8ba4\u503c\uff0c\u4e00\u65e6\u8bbe\u7f6e\u9ed8\u8ba4\u503c\uff0c\u5728\u63d2\u5165\u6570\u636e\u65f6\uff0c\u5982\u679c\u6b64\u5b57\u6bb5\u6ca1\u6709\u663e\u5f0f\u8d4b\u503c\uff0c\u5219\u8d4b\u503c\u4e3a\u9ed8\u8ba4\u503c\u3002 \u5173\u952e\u5b57 DEFAULT<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#9.DEFAULT\u7ea6\u675f\n#9.1 \u5728CREATE TABLE\u6dfb\u52a0\u7ea6\u675f\nCREATE TABLE test11(\nid INT,\nlast_name VARCHAR(15),\nsalary DECIMAL(10,2) DEFAULT 2000\n);\n\nDESC test11;\n\nINSERT INTO test11(id,last_name,salary)\nVALUES(1,'Tom',3000);\n\nINSERT INTO test11(id,last_name)\nVALUES(2,'Tom1');\n\nSELECT * \nFROM test11;\n\n#9.2 \u5728ALTER TABLE\u6dfb\u52a0\u7ea6\u675f\nCREATE TABLE test12(\nid INT,\nlast_name VARCHAR(15),\nsalary DECIMAL(10,2)\n);\n\nDESC test12;\n\nALTER TABLE test12\nMODIFY salary DECIMAL(8,2) DEFAULT 2500;\n\n#9.3 \u5728ALTER TABLE\u5220\u9664\u7ea6\u675f\nALTER TABLE test12\nMODIFY salary DECIMAL(8,2);\n\n\nSHOW CREATE TABLE test12;<\/code><\/pre>\n\n\n\n<p>\u9762\u8bd51\u3001\u4e3a\u4ec0\u4e48\u5efa\u8868\u65f6\uff0c\u52a0 not null default '' \u6216 default 0<br>\u7b54\uff1a\u4e0d\u60f3\u8ba9\u8868\u4e2d\u51fa\u73b0 null \u503c\u3002<\/p>\n\n\n\n<p>\u9762\u8bd52\u3001\u4e3a\u4ec0\u4e48\u4e0d\u60f3\u8981 null \u7684\u503c<br>\u7b54\uff1a\uff081\uff09\u4e0d\u597d\u6bd4\u8f83\u3002null \u662f\u4e00\u79cd\u7279\u6b8a\u503c\uff0c\u6bd4\u8f83\u65f6\u53ea\u80fd\u7528\u4e13\u95e8\u7684 is null \u548c is not null \u6765\u6bd4\u8f83\u3002\u78b0\u5230\u8fd0\u7b97\u7b26\uff0c\u901a\u5e38\u8fd4\u56de null\u3002<br>\uff082\uff09\u6548\u7387\u4e0d\u9ad8\u3002\u5f71\u54cd\u63d0\u9ad8\u7d22\u5f15\u6548\u679c\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u5f80\u5f80\u5728\u5efa\u8868\u65f6 not null default '' \u6216 default 0<\/p>\n\n\n\n<p>\u9762\u8bd53\u3001\u5e26 AUTO_INCREMENT \u7ea6\u675f\u7684\u5b57\u6bb5\u503c\u662f\u4ece 1 \u5f00\u59cb\u7684\u5417\uff1f\u5728 MySQL \u4e2d\uff0c\u9ed8\u8ba4 AUTO_INCREMENT \u7684\u521d\u59cb\u503c\u662f 1\uff0c\u6bcf\u65b0\u589e\u4e00\u6761\u8bb0\u5f55\uff0c\u5b57\u6bb5\u503c\u81ea\u52a8\u52a0 1\u3002\u8bbe\u7f6e\u81ea\u589e\u5c5e\u6027\uff08AUTO_INCREMENT\uff09\u7684\u65f6\u5019\uff0c\u8fd8\u53ef\u4ee5\u6307\u5b9a\u7b2c\u4e00\u6761\u63d2\u5165\u8bb0\u5f55\u7684\u81ea\u589e\u5b57\u6bb5\u7684\u503c\uff0c\u8fd9\u6837\u65b0\u63d2\u5165\u7684\u8bb0\u5f55\u7684\u81ea\u589e\u5b57\u6bb5\u503c\u4ece\u521d\u59cb\u503c\u5f00\u59cb\u9012\u589e\uff0c\u5982\u5728\u8868\u4e2d\u63d2\u5165\u7b2c\u4e00\u6761\u8bb0\u5f55\uff0c\u540c\u65f6\u6307\u5b9a id \u503c\u4e3a 5\uff0c\u5219\u4ee5\u540e\u63d2\u5165\u7684\u8bb0\u5f55\u7684 id \u503c\u5c31\u4f1a\u4ece 6 \u5f00\u59cb\u5f80\u4e0a\u589e\u52a0\u3002\u6dfb\u52a0\u4e3b\u952e\u7ea6\u675f\u65f6\uff0c\u5f80\u5f80\u9700\u8981\u8bbe\u7f6e\u5b57\u6bb5\u81ea\u52a8\u589e\u52a0\u5c5e\u6027\u3002<\/p>\n\n\n\n<p>\u9762\u8bd54\u3001\u5e76\u4e0d\u662f\u6bcf\u4e2a\u8868\u90fd\u53ef\u4ee5\u4efb\u610f\u9009\u62e9\u5b58\u50a8\u5f15\u64ce\uff1f\u5916\u952e\u7ea6\u675f\uff08FOREIGN KEY\uff09\u4e0d\u80fd\u8de8\u5f15\u64ce\u4f7f\u7528\u3002<br>MySQL \u652f\u6301\u591a\u79cd\u5b58\u50a8\u5f15\u64ce\uff0c\u6bcf\u4e00\u4e2a\u8868\u90fd\u53ef\u4ee5\u6307\u5b9a\u4e00\u4e2a\u4e0d\u540c\u7684\u5b58\u50a8\u5f15\u64ce\uff0c\u9700\u8981\u6ce8\u610f\u7684\u662f\uff1a\u5916\u952e\u7ea6\u675f\u662f\u7528\u6765\u4fdd\u8bc1\u6570\u636e\u7684\u53c2\u7167\u5b8c\u6574\u6027\u7684\uff0c\u5982\u679c\u8868\u4e4b\u95f4\u9700\u8981\u5173\u8054\u5916\u952e\uff0c\u5374\u6307\u5b9a\u4e86\u4e0d\u540c\u7684\u5b58\u50a8\u5f15\u64ce\uff0c\u90a3\u4e48\u8fd9\u4e9b\u8868\u4e4b\u95f4\u662f\u4e0d\u80fd\u521b\u5efa\u5916\u952e\u7ea6\u675f\u7684\u3002\u6240\u4ee5\u8bf4\uff0c\u5b58\u50a8\u5f15\u64ce\u7684\u9009\u62e9\u4e5f\u4e0d\u5b8c\u5168\u662f\u968f\u610f\u7684\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">\u8bfe\u540e\u7ec3\u4e60<\/h1>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u7b2c13\u7ae0_\u7ea6\u675f\u7684\u8bfe\u540e\u7ec3\u4e60\n\n#\u7ec3\u4e601\uff1a\nCREATE DATABASE test04_emp;\n\nUSE test04_emp;\n\nCREATE TABLE emp2(\nid INT,\nemp_name VARCHAR(15)\n);\n\nCREATE TABLE dept2(\nid INT,\ndept_name VARCHAR(15)\n);\n\n#1.\u5411\u8868emp2\u7684id\u5217\u4e2d\u6dfb\u52a0PRIMARY KEY\u7ea6\u675f\n\nALTER TABLE emp2\nADD CONSTRAINT pk_emp2_id PRIMARY KEY(id);\n\n\n#2.\u5411\u8868dept2\u7684id\u5217\u4e2d\u6dfb\u52a0PRIMARY KEY\u7ea6\u675f\n\nALTER TABLE dept2\nADD PRIMARY KEY(id);\n\n\n#3.\u5411\u8868emp2\u4e2d\u6dfb\u52a0\u5217dept_id\uff0c\u5e76\u5728\u5176\u4e2d\u5b9a\u4e49FOREIGN KEY\u7ea6\u675f\uff0c\u4e0e\u4e4b\u76f8\u5173\u8054\u7684\u5217\u662fdept2\u8868\u4e2d\u7684id\u5217\u3002\n\nALTER TABLE emp2\nADD dept_id INT;\n\nDESC emp2;\n\nALTER TABLE emp2\nADD CONSTRAINT fk_emp2_deptid FOREIGN KEY(dept_id) REFERENCES dept2(id);\n\n#\u7ec3\u4e602\uff1a\n#\u627f\u63a5\u300a\u7b2c11\u7ae0_\u6570\u636e\u5904\u7406\u4e4b\u589e\u5220\u6539\u300b\u7684\u7efc\u5408\u6848\u4f8b\u3002\nUSE test01_library;\n\nDESC books;\n\n#\u6839\u636e\u9898\u76ee\u8981\u6c42\u7ed9books\u8868\u4e2d\u7684\u5b57\u6bb5\u6dfb\u52a0\u7ea6\u675f\n#\u65b9\u5f0f1\uff1a\nALTER TABLE books\nADD PRIMARY KEY (id);\n\nALTER TABLE books\nMODIFY id INT AUTO_INCREMENT;\n#\u65b9\u5f0f2\uff1a\nALTER TABLE books\nMODIFY id INT PRIMARY KEY AUTO_INCREMENT;\n\n\n#\u9488\u5bf9\u4e8e\u975eid\u5b57\u6bb5\u7684\u64cd\u4f5c\nALTER TABLE books\nMODIFY NAME VARCHAR(50) NOT NULL;\n\nALTER TABLE books\nMODIFY AUTHORS VARCHAR(100) NOT NULL;\n\nALTER TABLE books\nMODIFY price FLOAT NOT NULL;\n\nALTER TABLE books\nMODIFY pubdate YEAR NOT NULL;\n\nALTER TABLE books\nMODIFY num INT NOT NULL;\n\n\n#\u7ec3\u4e603\uff1a\n\n#1. \u521b\u5efa\u6570\u636e\u5e93test04_company\nCREATE DATABASE IF NOT EXISTS test04_company CHARACTER SET 'utf8';\n\nUSE test04_company;\n\n#2. \u6309\u7167\u4e0b\u8868\u7ed9\u51fa\u7684\u8868\u7ed3\u6784\u5728test04_company\u6570\u636e\u5e93\u4e2d\u521b\u5efa\u4e24\u4e2a\u6570\u636e\u8868offices\u548cemployees\n\nCREATE TABLE IF NOT EXISTS offices(\nofficeCode INT(10) PRIMARY KEY ,\ncity VARCHAR(50) NOT NULL,\naddress VARCHAR(50) ,\ncountry VARCHAR(50) NOT NULL,\npostalCode VARCHAR(15),\nCONSTRAINT uk_off_poscode UNIQUE(postalCode)\n\n);\n\nDESC offices;\n\nCREATE TABLE employees(\nemployeeNumber INT PRIMARY KEY AUTO_INCREMENT,\nlastName VARCHAR(50) NOT NULL,\nfirstName VARCHAR(50) NOT NULL,\nmobile VARCHAR(25) UNIQUE,\nofficeCode INT(10) NOT NULL,\njobTitle VARCHAR(50) NOT NULL,\nbirth DATETIME NOT NULL,\nnote VARCHAR(255),\nsex VARCHAR(5),\nCONSTRAINT fk_emp_offcode FOREIGN KEY (officeCode) REFERENCES offices(officeCode)\n\n);\n\nDESC employees;\n\n#3. \u5c06\u8868employees\u7684mobile\u5b57\u6bb5\u4fee\u6539\u5230officeCode\u5b57\u6bb5\u540e\u9762\nALTER TABLE employees\nMODIFY mobile VARCHAR(25) AFTER officeCode;\n\n#4. \u5c06\u8868employees\u7684birth\u5b57\u6bb5\u6539\u540d\u4e3aemployee_birth\nALTER TABLE employees\nCHANGE birth employee_birth DATETIME;\n\n#5. \u4fee\u6539sex\u5b57\u6bb5\uff0c\u6570\u636e\u7c7b\u578b\u4e3aCHAR(1)\uff0c\u975e\u7a7a\u7ea6\u675f\nALTER TABLE employees\nMODIFY sex CHAR(1) NOT NULL;\n\n\n#6. \u5220\u9664\u5b57\u6bb5note\nALTER TABLE employees\nDROP COLUMN note;\n\n#7. \u589e\u52a0\u5b57\u6bb5\u540dfavoriate_activity\uff0c\u6570\u636e\u7c7b\u578b\u4e3aVARCHAR(100)\nALTER TABLE employees\nADD favoriate_activity VARCHAR(100);\n\n#8. \u5c06\u8868employees\u540d\u79f0\u4fee\u6539\u4e3aemployees_info\nRENAME TABLE employees\nTO employees_info;\n\n#\u9519\u8bef\uff1aTable 'test04_company.employees' doesn't exist\nDESC employees;\n\nDESC employees_info;<img loading=\"lazy\" decoding=\"async\" height=\"15\" width=\"15\" src=\"blob:https:\/\/eve2333.top\/6d1fb86d-3158-458c-b115-aedcb704d1e4\"><\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp;\u7b2c13\u7ae0_\u7ea6\u675fconstraint \u6570\u636e\u5b8c\u6574\u6027\uff08Data Integrity\uff09\u662f\u6307\u6570\u636e\u7684\u7cbe\u786e\u6027\uff08Accuracy\uff09\u548c\u53ef &#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-860","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\/860","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=860"}],"version-history":[{"count":1,"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/posts\/860\/revisions"}],"predecessor-version":[{"id":861,"href":"https:\/\/eve2333.top\/index.php?rest_route=\/wp\/v2\/posts\/860\/revisions\/861"}],"wp:attachment":[{"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=860"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=860"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/eve2333.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=860"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}