{"id":27,"date":"2024-07-22T02:48:14","date_gmt":"2024-07-21T18:48:14","guid":{"rendered":"http:\/\/47.121.197.82\/?p=21"},"modified":"2024-07-22T02:48:14","modified_gmt":"2024-07-21T18:48:14","slug":"mysql%e4%bd%bf%e7%94%a8-%e5%9f%ba%e7%a1%80%e7%af%87","status":"publish","type":"post","link":"https:\/\/www.chencuo.top\/?p=27","title":{"rendered":"mysql\u4f7f\u7528-\u57fa\u7840\u7bc7"},"content":{"rendered":"

MySQL\u662f\u4e00\u79cd\u5f00\u6e90\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7ba1\u7406<\/a>\u7cfb\u7edf\uff0c\u7531\u745e\u5178MySQL AB\u516c\u53f8\u5f00\u53d1\uff0c\u73b0\u5728\u7531Oracle\u516c\u53f8\u7ef4\u62a4\u3002MySQL\u652f\u6301\u591a\u4e2a\u64cd\u4f5c\u7cfb\u7edf\uff0c\u5305\u62ecLinux<\/a>\u3001Windows<\/a>\u3001macOS\u7b49\u3002\u5b83\u662f\u4e00\u79cd\u5ba2\u6237\u7aef\/\u670d\u52a1\u5668\u6a21\u5f0f\u7684\u6570\u636e\u5e93\uff0c\u63d0\u4f9b\u9ad8\u6548\u3001\u53ef\u9760\u3001\u7a33\u5b9a\u7684\u6570\u636e\u5b58\u50a8\u548c\u7ba1\u7406\u670d\u52a1\u3002MySQL\u662f\u76ee\u524d\u6700\u6d41\u884c\u7684\u5f00\u6e90\u5173\u7cfb\u578b\u6570\u636e\u5e93<\/a>\u4e4b\u4e00\uff0c\u88ab\u5e7f\u6cdb\u5e94\u7528\u4e8eWeb\u5e94\u7528\u7a0b\u5e8f\u3001\u4f01\u4e1a\u5e94\u7528\u7a0b\u5e8f\u548c\u79fb\u52a8\u5e94\u7528\u7a0b\u5e8f\u7b49\u9886\u57df\u3002\u5728\u672c\u6587\u7ae0\u4e2d\uff0c\u6211\u5c06\u4f1a\u7ed9\u51fa\u4e00\u4e9b\u57fa\u672c\u7684mysql\u4f7f\u7528\u65b9\u6cd5\uff0c\u5305\u62ec\uff1aSQL\uff0c\u51fd\u6570\uff0c\u7ea6\u675f\uff0c\u591a\u8868\u67e5\u8be2\uff0c\u4e8b\u7269\u7b49\u5185\u5bb9\u3002<\/span><\/p>\n\n\n

SQL<\/h2>\n\n\n\n

SQL\u4e3b\u8981\u5305\u62ec\uff1a<\/p>\n\n\n\n

DDL(Data Definition Language) —\u6570\u636e\u5e93\u5b9a\u4e49\u8bed\u8a00\uff0c\u7528\u6765\u5b9a\u4e49\u6570\u636e\u5e93\u5bf9\u8c61(\u6570\u636e\u5e93,\u8868\uff0c\u5b57\u6bb5)\u3002<\/p>\n\n\n\n

DML(Data Manipulation Language) —\u6570\u636e\u64cd\u4f5c\u8bed\u8a00\uff0c\u7528\u6765\u5bf9\u6570\u636e\u5e93\u8868\u4e2d\u7684\u6570\u636e\u8fdb\u884c\u589e\u5220\u6539\u3002<\/p>\n\n\n\n

DQL(Data Query Language) —\u6570\u636e\u5e93\u67e5\u8be2\u8bed\u8a00\uff0c\u7528\u6765\u67e5\u8be2\u6570\u636e\u5e93\u4e2d\u8868\u7684\u8bb0\u5f55\u3002<\/p>\n\n\n\n

DCL(Data Control Language) —\u6570\u636e\u63a7\u5236\u8bed\u8a00\uff0c\u7528\u6765\u521b\u5efa\u6570\u636e\u5e93\u7528\u6237\uff0c\u63a7\u5236\u6570\u636e\u5e93\u7684\u8bbf\u95ee\u6743\u9650\u3002<\/p>\n\n\n\n

<\/p>\n\n\n\n

DDL\u64cd\u4f5c<\/h3>\n\n\n\n

DDL-\u6570\u636e\u5e93\u64cd\u4f5c\uff1a<\/strong><\/p>\n\n\n\n

\u67e5\u8be2\uff1a\nshow databases\uff1b             ##\u67e5\u8be2\u6240\u6709\u6570\u636e\u5e93\nselect database();           ##\u67e5\u8be2\u5f53\u524d\u6570\u636e\u5e93\n\u521b\u5efa\uff1a\ncreate database + \u540d\u79f0;                   #\u76f4\u63a5\u521b\u5efa\ncreate database + if not exists + \u5e93\u540d;            #\u5e0c\u671b\u4e0d\u62a5\u9519\u521b\u5efa\ncreate database + \u5e93\u540d + default charset + \u7c7b\u578b;   #\u521b\u5efa\u6570\u636e\u5e93\u5e76\u5236\u5b9a\u5b57\u7b26\u96c6\n\u5220\u9664\uff1a\ndrop database+ \u5e93\u540d\uff1b\ndrop database if exists + \u5e93\u540d;         #\u4e0d\u62a5\u9519\u521b\u5efa\n\u4f7f\u7528\uff1a\nuse + \u5e93\u540d<\/code><\/pre>\n\n\n\n
DDL-\u6570\u636e\u8868\u64cd\u4f5c<\/strong><\/p>\n\n\n\n
\u67e5\u8be2\uff1a\nshow   tables;               #\u67e5\u8be2\u6240\u6709\u8868\ndesc + \u8868\u540d                  #\u67e5\u8be2\u8868\u7ed3\u6784\nshow  create table + \u8868\u540d    #\u67e5\u8be2\u8868\u7684\u5177\u4f53\u4fe1\u606f\n\u521b\u5efa\uff1a\ncreate table + \u8868\u540d(\n           \u5b57\u6bb51  \u5b57\u6bb51\u7c7b\u578b comment,\n           \u5b57\u6bb52  \u5b57\u6bb52\u7c7b\u578b comment, \n           \u5b57\u6bb53  \u5b57\u6bb53\u7c7b\u578b comment           \n            ) comment;<\/code><\/pre>\n\n\n\n
DDL-\u8868\u7684\u4fee\u6539<\/strong><\/p>\n\n\n\n
alter table + \u8868\u540d + add \u5b57\u6bb5n \u5b57\u6bb5n\u7c7b\u578b  comment;                          ##\u6dfb\u52a0\nalter table + \u8868\u540d + modify \u5b57\u6bb5\u540d \u4fee\u6539\u540e\u7684\u5b57\u6bb5\u7c7b\u578b;                        ##\u4fee\u6539\u5b57\u6bb5\u7c7b\u578b\n\nalter table + \u8868\u540d + change \u539f\u5b57\u6bb5\u540d \u66f4\u6539\u540e\u5b57\u6bb5\u540d \u66f4\u6539\u540e\u5b57\u6bb5\u7c7b\u578b comment;   ##\u4fee\u6539\u5b57\u6bb5\u540d\u548c\u5b57\u6bb5\u7c7b\u578b\nalter table + \u8868\u540d + drop \u5b57\u6bb5\u540d;               ##\u5220\u9664\u8868\u5b57\u6bb5\u7c7b\u578b\nalter table + \u8868\u540d + rename to +\u66f4\u6539\u540e\u8868\u540d;     ##\u66f4\u6539\u8868\u540d\ndrop table  if exists +\u5e93\u540d                     ##\u6570\u636e\u8868\u7684\u5220\u9664\ntruncate table + \u8868\u540d                           ##\u6570\u636e\u8868\u5220\u9664\u91cd\u65b0\u521b\u7acb                      <\/code><\/pre>\n\n\n\n
1.\u6570\u503c\u7c7b\u578b<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u89e3\u91ca\uff1a<\/p>\n\n\n\n
\u5982\u5e74\u9f84\uff0c\u9009\u62e9 tinyint \u7531\u4e8e\u5e74\u9f84\u6ca1\u6709\u8d1f\u6570 \u9009\u62e9\u65e0\u7b26\u53f7(unsigned)<\/p>\n\n\n\n
age tinyint unsigned<\/p>\n\n\n\n
\u5982\u5206\u6570\uff1a\u4fdd\u7559\u4e00\u4f4d\u5c0f\u6570<\/p>\n\n\n\n
score double(4,1) \u7b2c\u4e00\u4f4d\u53c2\u6570\u8868\u793a\u5168\u90e8\u957f\u5ea6\uff0c\u7b2c\u4e8c\u4e2a\u8868\u793a\u5c0f\u6570\u70b9\u957f\u5ea6 \u5305\u62ec\u5c0f\u6570\u70b9<\/p>\n\n\n\n
2.\u5b57\u7b26\u4e32\u7c7b\u578b<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u89e3\u91ca\uff1a<\/p>\n\n\n\n
\u5e26blob\u4ee3\u8868\u4e8c\u8fdb\u5236\u6570\u636e text\u4ee3\u8868\u6587\u672c\u6570\u636e<\/p>\n\n\n\n
blob\u7528\u7684\u4e0d\u591a<\/p>\n\n\n\n
\u4f7f\u7528\u5b9a\u957f\uff0c\u5982char(10)\u4f7f\u7528\u5b9a\u957f\u5b57\u7b26\u4e32\uff0c\u4e0d\u591f10\uff0c\u5219\u7528\u7a7a\u683c\u586b\u5145<\/p>\n\n\n\n
\u4f7f\u7528\u53d8\u957f\uff0c\u5982varchar(10)\u4f7f\u7528\u53d8\u957f\u5b57\u7b26\u4e32\uff0c\u4e0d\u4f1a \u586b\u5145\uff0c\u7528\u591a\u5c11\u5360\u7528\u591a\u5c11<\/p>\n\n\n\n
\u5dee\u5f02\uff1a<\/p>\n\n\n\n
char \u6027\u80fd\u597d<\/p>\n\n\n\n
varchar \u6027\u80fd\u5dee<\/p>\n\n\n\n
\u5b9e\u4f8b\uff1a\u5982\u7528\u6237\u540d \uff1a \u540d\u5b57\u586b\u5145\u662f\u4e0d\u4e00\u5b9a\u7684\u6709\u56fa\u5b9a\u4e2a\u6570\uff0c\u6240\u4ee5\u9009\u62e9varchar<\/p>\n\n\n\n
            \u5982\u6027\u522b\uff1a\u6027\u522b\u53ea\u6709\u4e00\u4e2a\u6570\u5b57 \uff0c\u5219\u4f7f\u7528var\u66f4\u597d<\/p>\n\n\n\n
3.\u65e5\u671f\u7c7b\u578b<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
DML\u64cd\u4f5c<\/h3>\n\n\n\n
DML-\u6570\u636e\u6dfb\u52a0\uff0c\u4fee\u6539\uff0c\u5220\u9664<\/strong><\/p>\n\n\n\n
\u7ed9\u6307\u5b9a\u5b57\u6bb5\u6dfb\u52a0\u6570\u636e:\ninsert into \u8868\u540d(\u5b57\u6bb5\u4e00\uff0c\u5b57\u6bb5\u4e8c....) values(\u503c1\uff0c\u503c2\uff0c...);\n\n\u7ed9\u5168\u90e8\u5b57\u6bb5\u6dfb\u52a0\u6570\u636e\uff1a\ninsert into \u8868\u540dvalues(\u503c1\uff0c\u503c2\uff0c....);\n\n\u6279\u91cf\u6dfb\u52a0\u6570\u636e:\ninsert into \u8868\u540d (\u5b57\u6bb51\uff0c\u5b57\u6bb52\uff0c....) values(\u503c1\uff0c\u503c2\uff0c\u3002\u3002\u3002),(\u503c1\uff0c\u503c2\uff0c\u3002\u3002\u3002);\ninsert into \u8868\u540dvalues(\u503c1\uff0c\u503c2\uff0c\u3002\u3002\u3002)\uff0c(\u503c1\uff0c\u503c2\uff0c...)\uff0c(\u503c1\uff0c\u503c2,..);\n\n\u4fee\u6539\u6570\u636e:\nupdate + \u8868\u540d + set \u5b57\u6bb51=\uff0c\u5b57\u6bb52=\uff0c where + \u6761\u4ef6(\u7528\u4e8e\u6dfb\u52a0\u9009\u62e9\u5230\u6307\u5b9a\u5b57\u6bb5\u7684\u6761\u4ef6)  #\u4e0d\u5e26where \u6761\u4ef6\uff0c\u9ed8\u8ba4\u4fee\u6539\u5168\u90e8\u5185\u5bb9\n\n\u5220\u9664\u6570\u636e\uff1adelete from + \u8868\u540d + where\u6761\u4ef6\n\n##  delete \u82e5\u6ca1\u6709where \u6761\u4ef6\uff0c\u9ed8\u8ba4\u5220\u9664\u6240\u6709\u6570\u636e\uff1b\n\n##  delete \u8bed\u53e5\u4e0d\u80fd\u5220\u9664\u6478\u4e00\u4e2a\u5b57\u6bb5\u7684\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528update<\/code><\/pre>\n\n\n\n
DQL\u64cd\u4f5c<\/h3>\n\n\n\n
DQL-\u6570\u636e\u8868\u67e5\u8be2<\/strong><\/p>\n\n\n\n
select [all|distinct] <\u76ee\u6807\u5217\u7684\u8868\u8fbe\u5f0f1> [\u522b\u540d],
 <\u76ee\u6807\u5217\u7684\u8868\u8fbe\u5f0f2> [\u522b\u540d]…
from <\u8868\u540d\u6216\u89c6\u56fe\u540d> [\u522b\u540d],
<\u8868\u540d\u6216\u89c6\u56fe\u540d> [\u522b\u540d]…
[where<\u6761\u4ef6\u8868\u8fbe\u5f0f>]
[group by <\u5217\u540d>
 [having <\u6761\u4ef6\u8868\u8fbe\u5f0f>]]
[order by <\u5217\u540d> [asc|desc]]
[limit <\u6570\u5b57\u6216\u8005\u5217\u8868>];<\/p>\n\n\n\n
\u57fa\u672c\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u67e5\u8be2\u591a\u4e2a\u5b57\u6bb5\uff1a\nselect \u5b57\u6bb51\uff0c\u5b57\u6bb52\uff0c\u5b57\u6bb53\uff0c...from \u8868\u540d\uff1b\nselect * from \u8868\u540d\uff1b\n\n\u8bbe\u7f6e\u522b\u540d\uff1a\nselect \u5b57\u6bb51[as \u522b\u540d1],\u5b57\u6bb52[as \u522b\u540d2] .....from \u8868\u540d\uff1b as \u53ef\u4ee5\u7701\u7565\n\n\u53bb\u9664\u91cd\u590d\u8bb0\u5f55:\nselect distinct \u5b57\u6bb5\u5217\u8868 from \u8868\u540d\uff1b<\/code><\/pre>\n\n\n\n
\u6761\u4ef6\u67e5\u8be2<\/strong><\/p>\n\n\n\n
select \u5b57\u6bb5\u5217\u8868 from \u8868\u540d where \u6761\u4ef6\u5217\u8868;<\/code><\/pre>\n\n\n\n
1.\u6bd4\u8f83\u8fd0\u7b97\u7b26<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u8be0\u91ca\uff1a\u5728\u4e24\u4e2a\u6570\u4e4b\u95f4 \u53ef\u4ee5\u7528\uff1abetween and\uff0cand\uff0c&&<\/p>\n\n\n\n
           \u5728\u591a\u4e2a\u6570\u4e4b\u95f4(\u6216\u8005\uff0c\u6216\u8005) :or\u2026or ,in(\u6570\u503c1\uff0c\u6570\u503c2\uff0c\u6570\u503c3)<\/p>\n\n\n\n
           like\u5360\u4f4d\u7b26(\u6a21\u7cca\u5339\u914d) \u8868\u793a\u65b9\u6cd5”__<\/em>“\u4e24\u4e2a\u4e0b\u5212\u7ebf\uff0c\u4e24\u4e2a\u5b57\u7b26 % \u8868\u793a\u6700\u540e\u4e00\u4e2a\u6570\u503c\u4e3a\u591a\u5c11 %x \u8868\u793a\u6700\u540e\u4e00\u4e2a\u5b57\u7b26\u4e3aX<\/p>\n\n\n\n
2.\u903b\u8f91\u8fd0\u7b97\u7b26<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u805a\u5408\u67e5\u8be2<\/strong><\/p>\n\n\n\n
select \u805a\u5408\u51fd\u6570(\u5b57\u6bb5\u5217\u8868) from \u8868\u540d\uff1a\n<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u8be0\u91ca\uff1a\u4f7f\u7528\u805a\u5408\u51fd\u6570\u67e5\u8be2\u662f\u7eb5\u5411\u67e5\u8be2\uff0c\u5b83\u662f\u5bf9\u4e00\u5217\u7684\u503c\u8fdb\u884c\u8ba1\u7b97\uff0c\u7136\u540e\u8fd4\u56de\u4e00\u4e2a\u5355\u4e00\u7684\u503c\uff1b\u53e6\u5916\u805a\u5408\u51fd\u6570\u4f1a\u5ffd\u7565\u7a7a\u503c\u3002<\/p>\n\n\n\n
\u5206\u7ec4\u67e5\u8be2<\/strong><\/p>\n\n\n\n
select  \u5b57\u6bb5\u5217\u8868 from  \u8868\u540d where  \u6761\u4ef6\u5217\u8868  group by +\u5206\u7ec4\u540e\u5b57\u6bb5\u540d having +\u5206\u7ec4\u540e\u6761\u4ef6;<\/code><\/pre>\n\n\n\n
\u5206\u7ec4\u4e4b\u540e\u5bf9\u7edf\u8ba1\u7ed3\u679c\u8fdb\u884c\u7b5b\u9009\u7684\u8bdd\u5fc5\u987b\u4f7f\u7528having\uff0c\u4e0d\u80fd\u4f7f\u7528where\u3002<\/p>\n\n\n\n
where\u5b50\u53e5\u7528\u6765\u7b5b\u9009 FROM \u5b50\u53e5\u4e2d\u6307\u5b9a\u7684\u64cd\u4f5c\u6240\u4ea7\u751f\u7684\u884c\u3002<\/p>\n\n\n\n
group by \u5b50\u53e5\u7528\u6765\u5206\u7ec4 WHERE \u5b50\u53e5\u7684\u8f93\u51fa\u3002 <\/p>\n\n\n\n
having \u5b50\u53e5\u7528\u6765\u4ece\u5206\u7ec4\u7684\u7ed3\u679c\u4e2d\u7b5b\u9009\u884c<\/p>\n\n\n\n
\u6392\u5e8f\u67e5\u8be2<\/strong><\/p>\n\n\n\n
select \u5b57\u6bb5\u5217\u8868 from \u8868\u540d order by \u5b57\u6bb51 \u6392\u5e8f\u65b9\u5f0f1\uff0c\u5b57\u6bb5\u4e8c \uff0c\u6392\u5e8f\u65b9\u5f0f2asc; <\/code><\/pre>\n\n\n\n
asc \uff1a \u5347\u5e8f(\u9ed8\u8ba4)<\/p>\n\n\n\n
desc\uff1a\u964d\u5e8f<\/p>\n\n\n\n
\u5206\u9875\u67e5\u8be2<\/strong><\/p>\n\n\n\n
select \u5b57\u6bb5\u5217\u8868 from \u8868\u540d limit \u8d77\u59cb\u7d22\u5f15\uff0c\u67e5\u8be2\u8bb0\u5f55\u6570;<\/code><\/pre>\n\n\n\n
\u8d77\u59cb\u7d22\u5f15\u4ece0\u5f00\u59cb\uff0c\u8d77\u59cb\u7d22\u5f15=\u67e5\u8be2\u9875\u7801(-1)*\u6bcf\u9875\u663e\u793a\u8bb0\u5f55\u6570\u3002<\/p>\n\n\n\n
\u5206\u9875\u67e5\u8be2\u662f\u6570\u636e\u5e93\u7684\u65b9\u8a00\uff0c\u4e0d\u540c\u7684\u6570\u636e\u5e93\u6709\u4e0d\u540c\u7684\u5b9e\u73b0\uff0cmysql\u4e2d\u662flimit<\/p>\n\n\n\n
\u5982\u679c\u67e5\u8be2\u662f\u7b2c\u4e00\u9875\u7684\u6570\u636e\uff0c\u8d77\u59cb\u7d22\u5f15\u53ef\u4ee5\u7701\u7565\uff0c\u76f4\u63a5\u7b80\u5199\u4e3alimit10<\/p>\n\n\n\n
\u6ce8\u610f\uff0c\u65e0\u8bba\u600e\u4e48\u67e5\u8be2\uff0c\u5206\u9875\u67e5\u8be2\u90fd\u653e\u5728\u6700\u540e\uff0c\u5305\u62ec\u5206\u7ec4<\/p>\n\n\n\n
\u5355\u72ec\u7684limit \u8868\u793a\u7b2c\u51e0\u4e2a\uff0c\u5982\u524d\u4e94\u4e2a\uff1alimit 5<\/p>\n\n\n\n
DCL\u64cd\u4f5c<\/h3>\n\n\n\n
DCL-\u7528\u6237\u7ba1\u7406<\/strong><\/p>\n\n\n\n
\u67e5\u8be2\u7528\u6237\nuse mysql                              ##\u7528\u6237\u4fe1\u606f\u4e00\u822c\u5b58\u653e\u5728mysql\u8fd9\u4e2a\u5e93\u5185\u7684user\u4e2dselect * from user\n\u521b\u5efa\u7528\u6237\ncreate user '\u7528\u6237\u540d'@'\u4e3b\u673a\u540d'  identified by    #\u5bc6\u7801\u4efb\u610f\u6570\u636e\u5e93\u8bbf\u95ee   '\u7528\u6237\u540d'@'%'\n\u4fee\u6539\u5bc6\u7801\nalter user '\u7528\u6237\u540d'@'\u4e3b\u673a\u540d'  identified with mysql_native_password by \u5bc6\u7801\n\u5220\u9664\u7528\u6237\ndrop user '\u7528\u6237\u540d'@'\u4e3b\u673a\u540d' <\/code><\/pre>\n\n\n\n
DCL-\u7528\u6237\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u67e5\u8be2\u7528\u6237\u6743\u9650\nshow grants for '\u7528\u6237\u540d'@'\u4e3b\u673a\u540d'\n\u6388\u4e88\u7528\u6237\u6743\u9650\ngrant \u6743\u9650\u540d on + \u6570\u636e\u5e93  to '\u7528\u6237\u540d'@'\u4e3b\u673a\u540d'\n\u64a4\u9500\u7528\u6237\u6743\u9650\nrevoke \u6743\u9650\u540d on + \u6570\u636e\u5e93 from '\u7528\u6237\u540d'@'\u4e3b\u673a\u540d'<\/code><\/pre>\n\n\n\n
1.\u6743\u9650\u8868<\/strong><\/p>\n\n\n\n
\u6743\u9650<\/td>\u8bf4\u660e<\/td><\/tr>
all\uff0call privileges<\/td>\u6240\u6709\u6743\u9650<\/td><\/tr>
select<\/td>\u67e5\u8be2\u6570\u636e<\/td><\/tr>
insert<\/td>\u63d2\u5165\u6570\u636e<\/td><\/tr>
update<\/td>\u4fee\u6539\u6570\u636e<\/td><\/tr>
delete<\/td>\u5220\u9664\u6570\u636e<\/td><\/tr>
alter<\/td>\u4fee\u6539\u8868<\/td><\/tr>
drop<\/td>\u5220\u9664\u6570\u636e\u5e93\/\u8868\/\u89c6\u56fe<\/td><\/tr>
create<\/td>\u521b\u5efa\u6570\u636e\u5e93\/\u8868<\/td><\/tr><\/tbody><\/table>
\u6ce8\u610f\uff1a
\u591a\u4e2a\u6743\u9650\u4e4b\u95f4\u7528\u9017\u53f7\u5206\u9694
\u6388\u6743\u65f6\uff0c\u6570\u636e\u5e93\u548c\u5e93\u540d\u53ef\u4ee5\u4f7f\u7528*\u8fdb\u884c\u901a\u914d\uff0c\u4ee3\u8868\u6240\u6709<\/figcaption><\/figure>\n\n\n\n
\u51fd\u6570<\/h2>\n\n\n\n
\u51fd\u6570\u5305\u62ec\uff1a\u6d41\u7a0b\u51fd\u6570\uff0c\u65e5\u671f\u51fd\u6570\uff0c\u6570\u503c\u51fd\u6570\uff0c\u5b57\u7b26\u4e32\u51fd\u6570<\/p>\n\n\n\n
\u5176\u4f7f\u7528\u65b9\u6cd5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u6765\u5b9a<\/p>\n\n\n\n
\u4e00\u822c\u7528\u6cd5<\/p>\n\n\n\n
select \u51fd\u6570\u540d() <\/code><\/pre>\n\n\n\n
\u5e38\u7528\u7684\u5b57\u7b26\u4e32\u51fd\u6570<\/strong><\/p>\n\n\n\n
\u51fd\u6570\u540d<\/td>\u529f\u80fd<\/td><\/tr>
concat(s1,s2\u2026.sn)<\/td>\u5b57\u7b26\u4e32\u62fc\u63a5 \u5c06s1\uff0cs2\uff0csn \u62fc\u63a5\u6210\u4e00\u4e2a\u5b57\u7b26\u4e32<\/td><\/tr>
lower(str)<\/td>\u5c06\u5b57\u7b26\u4e32str\u5168\u90e8\u8f6c\u6362\u4e3a\u5c0f\u5199<\/td><\/tr>
upper(str)<\/td>\u5c06\u5b57\u7b26\u4e32\u5168\u90e8\u8f6c\u6362\u4e3a\u5927\u5199<\/td><\/tr>
lpad(str,n,pad)<\/td>\u5de6\u586b\u5145 \u7528\u5b57\u7b26\u4e32pad\u5bf9str\u7684\u5de6\u8fb9\u8fdb\u884c\u586b\u5145\uff0c\u8fbe\u5230n\u4e2a\u5b57\u7b26\u4e32\u7684\u957f\u5ea6<\/td><\/tr>
rpad(str,n,pad)<\/td>\u53f3\u586b\u5145<\/td><\/tr>
trim(str)<\/td>\u53bb\u6389\u5b57\u7b26\u4e32\u5934\u90e8\u548c\u5c3e\u90e8\u7684\u7a7a\u683c<\/td><\/tr>
substring(str,start,len)<\/td>\u8fd4\u56de\u4ece\u5b57\u7b26\u4e32str\u4ecestart\u4f4d\u7f6e\u8d77\u7684len\u4e2a\u957f\u5ea6\u7684\u5b57\u7b26\u4e32 #\u7d22\u5f15\u503c\u4ece1\u5f00\u59cb<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u5e38\u7528\u7684\u6570\u503c\u51fd\u6570<\/strong><\/p>\n\n\n\n
\u51fd\u6570<\/td>\u529f\u80fd<\/td><\/tr>
ceil(x)<\/td>\u5411\u4e0a\u53d6\u6574<\/td><\/tr>
floor(x)<\/td>\u5411\u4e0b\u53d6\u6574<\/td><\/tr>
mod(x,y)<\/td>\u53d6\u6a21<\/td><\/tr>
rand()<\/td>\u8fd4\u56de0.1\u968f\u673a\u6570<\/td><\/tr>
round(x,y)<\/td>\u56db\u820d\u4e94\u5165<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u5e38\u7528\u7684\u65e5\u671f\u51fd\u6570<\/strong><\/p>\n\n\n\n
\u51fd\u6570\u540d<\/td>\u63cf\u8ff0<\/td><\/tr>
curdate()<\/td>\u8fd4\u56de\u5f53\u524d\u65f6\u95f4<\/td><\/tr>
curtime()<\/td>\u8fd4\u56de\u5f53\u524d\u65f6\u95f4<\/td><\/tr>
now()<\/td>\u8fd4\u56de\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4<\/td><\/tr>
year(date)<\/td>\u83b7\u53d6\u6307\u5b9adate\u7684\u5e74\u4efd<\/td><\/tr>
month(date)<\/td>\u83b7\u53d6\u6307\u5b9adate\u7684\u6708\u4efd<\/td><\/tr>
day(date)<\/td>\u83b7\u53d6\u6307\u5b9adate\u7684\u65e5\u671f<\/td><\/tr>
date_add(date,interval expr type)<\/td>\u8fd4\u56de\u4e00\u4e2a\u65e5\u671f\/\u65f6\u95f4\u503c\u52a0\u4e0a\u4e00\u4e2a\u65f6\u95f4\u95f4\u9694expr\u540e\u7684\u65f6\u95f4\u503c<\/td><\/tr>
datediff(date1,date2)<\/td>\u8fd4\u56de\u8d77\u59cb\u65f6\u95f4date1\u548c\u7ed3\u675f\u65f6\u95f4date2\u4e4b\u95f4\u7684\u5929\u6570<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u6d41\u7a0b\u51fd\u6570<\/strong><\/p>\n\n\n\n
\u51fd\u6570<\/td>\u529f\u80fd<\/td><\/tr>
if(value,t,f)<\/td>\u5982\u679cvalue\u4e3atrue,\u5219\u8fd4\u56det\uff0c\u5426\u5219\u53d1\u554a\u4f60\u4f1af<\/td><\/tr>
ifnull(value1,value2)<\/td>\u5982\u679cvalue1\u4e0d\u4e3a\u7a7a\uff0c\u5219\u8fd4\u56devalue1\uff0c\u5426\u5219\u8fd4\u56devalue2<\/td><\/tr>
case when [val1] then [res1] ..else [default] end<\/td>\u5982\u679cval1\u4e3atrue\uff0c\u5219\u8fd4\u56deres1,…..\u5219\u8fd4\u56dedefault\u9ed8\u8ba4\u503c<\/td><\/tr>
case [expr] when [val1] then [res1] .. else [default] end<\/td>\u5982\u679cexpr\u7684 \u503c\u7b49\u4e8eval1\uff0c\u5219\u8fd4\u56deres1\uff0c,…\u5426\u5219\u8fd4\u56dedefault\u9ed8\u8ba4\u503c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u7ea6\u675f<\/h2>\n\n\n\n
\u603b\u6982<\/h3>\n\n\n\n
\u6982\u8ff0\uff1a\u7ea6\u675f\u662f\u4f5c\u7528\u57df\u8868\u4e2d\u5b57\u6bb5\u4e0a\u7684\u89c4\u5219\uff0c\u7528\u4e8e\u9650\u5236\u5b58\u5728\u4e8e\u8868\u4e2d\u7684\u6570\u636e\u3002<\/p>\n\n\n\n
\u76ee\u7684\uff1a\u4fdd\u8bc1\u6570\u636e\u5e93\u4e2d\u6570\u636e\u7684\u6b63\u786e\uff0c\u6709\u6548\u6027\u548c\u5b8c\u6574\u6027<\/p>\n\n\n\n
\u7ea6\u675f\u540d<\/td>\u89e3\u91ca<\/td>\u8868\u8fbe\u5f0f<\/td><\/tr>
\u4e3b\u952e\u7ea6\u675f<\/td>\u4e3b\u952e\u662f\u4e00\u884c\u6570\u636e\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u91c7\u7528\u9ed8\u8ba4\u503c<\/td>primary key\uff08pk\uff09<\/td><\/tr>
\u975e\u7a7a\u7ea6\u675f<\/td>\u9650\u5236\u8be5\u5b57\u6bb5\u7684\u6570\u636e\u4e0d\u80fd\u4e3anull<\/td>not null<\/td><\/tr>
\u552f\u4e00\u6027\u7ea6\u675f<\/td>\u4fdd\u8bc1\u8be5\u5b57\u6bb5\u7684\u6240\u6709\u6570\u636e\u90fd\u662f\u552f\u4e00\uff0c\u4e0d\u91cd\u590d\u7684<\/td>unique<\/td><\/tr>
\u9ed8\u8ba4\u7ea6\u675f<\/td>\u4fdd\u5b58\u6570\u636e\u65f6\uff0c\u5982\u679c\u672a\u6307\u5b9a\u8be5\u5b57\u6bb5\u7684\u503c\uff0c\u5219\u91c7\u7528\u9ed8\u8ba4\u503c\uff0c\u6ce8\u610f\u4f7f\u7528default\u7684\u65f6\u5019 \u540e\u9762\u5e26\u7684\u503c\u4e3a\u5b57\u7b26\u4e32<\/td>default<\/td><\/tr>
\u5916\u952e\u7ea6\u675f<\/td>\u7528\u6765\u8ba9\u4e24\u5f20\u8868\u7684\u6570\u636e\u4e4b\u95f4\u5efa\u7acb\u8fde\u63a5\uff0c\u4fdd\u8bc1\u6570\u636e\u7684\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027<\/td>foreign key\uff08fk\uff09<\/td><\/tr>
\u68c0\u67e5\u7ea6\u675f(8.0.16\u7248\u672c\u4e4b\u540e)<\/td>\u4fdd\u8bc1\u5b57\u6bb5\u503c\u6ee1\u8db3\u4e00\u4e2a\u6761\u4ef6<\/td>check<\/td><\/tr>
\u81ea\u589e\u957f\u7ea6\u675f<\/td><\/td>auto_increment<\/td><\/tr>
\u96f6\u586b\u5145\u7ea6\u675f<\/td><\/td>zerofill<\/td><\/tr><\/tbody><\/table>
\u6ce8\u610f\uff1a\u5f53\u4e3b\u952e\u4e3anull\u65f6\u5019\uff0c\u89e6\u53d1not null \u76f4\u63a5\u62a5\u9519\u800c\u4e3b\u952e\u4e0d\u81ea\u589e\u52a0\uff0c\u800c\u540d\u5b57\u91cd\u590d\u65f6\uff0c\u7531\u4e8e\u518d\u4e00\u6b21\u7533\u8bf7\u4e86id\uff0c\u8fd9\u65f6\u5019\u4f1a\u81ea\u589e\u52a0\u4e3b\u952e\uff0c\u4f46\u7531\u4e8e\u552f\u4e00\u6027\u7ea6\u675f\uff0c\u6dfb\u52a0\u6b64\u6b21\u5185\u5bb9\u5931\u8d25\uff0c\u8fd9\u4e0e\u8fd0\u884c\u987a\u5e8f\u6709\u5173\uff0c\u4f46\u662f\u4e3b\u952e\u7ea6\u675f\u5df2\u8fd0\u884c\u3002\u53ea\u6709\u5f53unique\u552f\u4e00\u503c\u65f6\u5019\u3002<\/figcaption><\/figure>\n\n\n\n
\u5916\u952e\u7ea6\u675f<\/h3>\n\n\n\n
\u8be0\u91ca\uff1a<\/p>\n\n\n\n
\u5177\u6709\u5916\u952e\u7ea6\u675f\u7684\u8868\u53eb\u505a\u5b50\u8868\uff0c\u5916\u952e\u6240\u5173\u8054\u7684\u8868\u53eb\u505a\u7236\u8868<\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
create table \u8868\u540d( \n       \u5b57\u6bb5\u540d \u6570\u636e\u7c7b\u578b\n        ............\n       [constraint] [\u5916\u952e\u540d\u79f0] foreign key (\u5916\u952e\u5b57\u6bb5\u540d) references \u4e3b\u8868(\u4e3b\u8868\u5217\u540d)\n)\n\nalter table \u8868\u540d add constraint \u5916\u952e\u540d\u79f0 foreign key (\u5916\u952e\u5b57\u6bb5\u540d) references \u4e3b\u8868(\u4e3b\u8868\u5217\u540d)<\/code><\/pre>\n\n\n\n
\u5220\u9664\u5916\u952e<\/p>\n\n\n\n
alter table \u8868\u540d drop foreign key \u5916\u952e\u540d\u79f0<\/code><\/pre>\n\n\n\n
\u5916\u952e\u7ea6\u675f\uff1a<\/p>\n\n\n\n
\u5220\u9664\/\u66f4\u65b0\u884c\u4e3a<\/p>\n\n\n\n
\u540d\u79f0<\/td>\u8be0\u91ca<\/td><\/tr>
no action<\/td>\u5f53\u5728\u7236\u8868\u4e2d\u5220\u9664\/\u66f4\u65b0\u5bf9\u5e94\u8bb0\u5f55\u65f6\uff0c\u9996\u5148\u68c0\u67e5\u8be5\u8bb0\u5f55\u662f\u5426\u6709\u5bf9\u5e94\u5916\u952e\uff0c\u5982\u679c\u6709\u5219\u4e0d\u5141\u8bb8\u5220\u9664\/\u66f4\u65b0\u3002\u3010\u4e0eresrict\u4e00\u81f4\u3011<\/td><\/tr>
restrict<\/td>\u5f53\u5728\u7236\u8868\u4e2d\u5220\u9664\/\u66f4\u65b0\u5bf9\u5e94\u8bb0\u5f55\u65f6\uff0c\u9996\u5148\u68c0\u67e5\u8be5\u8bb0\u5f55\u662f\u5426\u6709\u5bf9\u5e94\u5916\u952e\uff0c\u5982\u679c\u6709\u5219\u4e0d\u5141\u8bb8\u5220\u9664\/\u66f4\u65b0\u3002\u3010\u4e0e no action\u4e00\u81f4\u3011<\/td><\/tr>
cascade<\/td>\u5f53\u5728\u7236\u8868\u4e2d\u5220\u9664\/\u66f4\u65b0\u5bf9\u5e94\u8bb0\u5f55\u65f6\uff0c\u9996\u5148\u68c0\u67e5\u8be5\u8bb0\u5f55\u662f\u5426\u6709\u5bf9\u5e94\u5916\u952e\uff0c\u5982\u679c\u6709\uff0c\u5219\u4e5f\u5220\u9664\/\u66f4\u65b0\u5916\u952e\u5728\u5b50\u8868\u4e2d\u7684\u8bb0\u5f55\u3002<\/td><\/tr>
set null<\/td>\u5f53\u5728\u7236\u8868\u4e2d\u5220\u9664\u5bf9\u5e94\u8bb0\u5f55\u65f6\uff0c\u9996\u5148\u68c0\u67e5\u8be5\u8bb0\u5f55\u662f\u5426\u6709\u5bf9\u5e94\u5916\u952e\uff0c\u5982\u679c\u6709\u5219\u8bbe\u7f6e\u5b50\u8868\u4e2d\u8be5\u5916\u952e\u503c\u4e3anull\uff0c\uff08\u8fd9\u5c31\u8981\u6c42\u6539\u5916\u952e\u5141\u8bb8\u4e3anull\uff09<\/td><\/tr>
set default<\/td>\u7236\u8868\u6709\u53d8\u66f4\u65f6\uff0c\u5b50\u8868\u5c06\u5916\u952e\u5217\u8bbe\u7f6e\u6210\u4e00\u4e2a\u9ed8\u8ba4\u7684\u503c\uff08lnnodb\u4e0d\u652f\u6301\uff09<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
alter table \u8868\u540d add constraint \u5916\u952e\u540d\u79f0 foreign key (\u5916\u952e\u5b57\u6bb5\u540d) references \u4e3b\u8868(\u4e3b\u8868\u5217\u540d) on update + \u884c\u4e3a on delete +\u884c\u4e3a \uff1b<\/code><\/pre>\n\n\n\n
\u591a\u8868\u67e5\u8be2<\/h2>\n\n\n\n
\u591a\u8868\u5173\u7cfb<\/h3>\n\n\n\n
\u6982\u8ff0\uff1a<\/p>\n\n\n\n
\u9879\u76ee\u5f00\u53d1\u4e2d\uff0c\u5728\u8fdb\u884c\u6570\u636e\u5e93\u8868\u7ed3\u6784\u8bbe\u8ba1\u65f6\uff0c\u4f1a\u6839\u636e\u4e1a\u52a1\u9700\u6c42\u53ca\u4e1a\u52a1\u6a21\u5757\u4e4b\u95f4\u7684\u5173\u7cfb\uff0c\u5206\u6790\u5e76\u8bbe\u8ba1\u8868\u7ed3\u6784\uff0c\u7531\u4e8e\u4e1a\u52a1\u4e4b\u95f4\u76f8\u4e92\u5173\u7cfb\uff0c\u6240\u4ee5\u5404\u4e2a\u8868\u7ed3\u6784\u4e4b\u95f4\u4e5f\u5b58\u5728\u7740\u5404\u79cd\u8054\u7cfb\uff0c\u57fa\u672c\u5206\u4e3a\u4e09\u79cd\uff1a\u4e00\u5bf9\u591a(\u591a\u5bf9\u4e00)\uff0c\u4e00\u5bf9\u4e00\uff0c\u591a\u5bf9\u591a\u3002<\/p>\n\n\n\n
\u4e00\u5bf9\u591a\uff1a<\/strong><\/p>\n\n\n\n
\u6848\u4f8b\uff1a\u90e8\u95e8\u4e0e\u5458\u5de5\u4e4b\u95f4\u7684\u5173\u7cfb<\/p>\n\n\n\n
\u5173\u7cfb\uff1a\u4e00\u4e2a\u90e8\u95e8\u5bf9\u5e94\u591a\u4e2a\u5458\u5de5\uff0c\u4e00\u4e2a\u5458\u5de5\u5bf9\u5e94\u4e00\u4e2a\u90e8\u95e8<\/p>\n\n\n\n
\u5b9e\u73b0\uff1a\u518d\u591a\u7684\u4e00\u65b9\u5efa\u7acb\u5916\u952e\uff0c\u6307\u5411\u4e00\u7684\u4e00\u65b9\u7684\u4e3b\u952e<\/p>\n\n\n\n
\u591a\u5bf9\u591a\uff1a<\/strong><\/p>\n\n\n\n
\u6848\u4f8b\uff1a\u5b66\u751f\u4e0e\u8bfe\u7a0b\u4e4b\u95f4\u7684\u5173\u7cfb<\/p>\n\n\n\n
\u5173\u7cfb\uff1a\u4e00\u4e2a\u5b66\u751f\u53ef\u4ee5\u9009\u62e9\u4fee\u591a\u95e8\u8bfe\u7a0b\uff0c\u4e00\u95e8\u8bfe\u7a0b\u4e5f\u53ef\u4ee5\u63d0\u4f9b\u7ed9\u591a\u4e2a\u5b66\u751f\u9009\u62e9<\/p>\n\n\n\n
\u5b9e\u73b0\uff1a\u5efa\u7acb\u7b2c\u4e09\u5f20\u4e2d\u95f4\u8868\uff0c\u4e2d\u95f4\u8868\u81f3\u5c11\u5305\u542b\u4e24\u4e2a\u5916\u952e\uff0c\u5206\u522b\u5173\u8054\u4e24\u65b9\u4e3b\u952e<\/p>\n\n\n\n
\u4e00\u5bf9\u4e00\uff1a<\/strong><\/p>\n\n\n\n
\u6848\u4f8b\uff1a\u7528\u6237\u4e0e\u7528\u6237\u8be6\u60c5\u7684\u5173\u7cfb<\/p>\n\n\n\n
\u5173\u7cfb\uff1a\u4e00\u5bf9\u4e00\u5173\u7cfb\uff0c\u591a\u7528\u4e8e\u8868\u5355\u62c6\u5206\uff0c\u5c06\u4e00\u5f20\u8868\u7684\u57fa\u7840\u5b57\u6bb5\u653e\u5728\u4e00\u5f20\u8868\u4e2d\uff0c\u5176\u4ed6\u8be6\u60c5\u5b57\u6bb5\u653e\u5728\u53e6\u4e00\u5f20\u8868\u4e2d\uff0c\u4ee5\u63d0\u5347\u64cd\u4f5c\u6548\u7387<\/p>\n\n\n\n
\u5b9e\u73b0\uff1a\u5728\u4efb\u610f\u4e00\u65b9\u52a0\u5165\u5916\u952e\uff0c\u5173\u8054\u53e6\u5916\u4e00\u65b9\u7684\u4e3b\u952e\uff0c\u5e76\u4e14\u8bbe\u7f6e\u5916\u952e\u4e3a\u552f\u4e00\u7684\uff08unique\uff09<\/p>\n\n\n\n
\u7b1b\u5361\u5c14\u79ef<\/h3>\n\n\n\n
\u6982\u5ff5\uff1a\u7b1b\u5361\u5c14\u4e58\u79ef\uff0c\u6307\u5728\u4e24\u4e2a\u96c6\u5408A\u548c\u96c6\u5408B\u7684\u6240\u6709\u7ec4\u5408\u60c5\u51b5\uff08\u591a\u8868\u67e5\u8be2\u9700\u8981\u6d88\u9664\u7b1b\u5361\u5c14\u79ef\uff09<\/p>\n\n\n\n
\u6d88\u9664\u65b9\u6cd5\uff1a\u627e\u5230\u4e00\u5bf9\u4e00\u4e2d\u7684\u5916\u952e\u548c\u4e3b\u952e\u76f8\u7b49<\/p>\n\n\n\n
\u591a\u8868\u67e5\u8be2\u65b9\u6cd5<\/h3>\n\n\n\n
\u57fa\u672c\uff1a<\/p>\n\n\n\n
select * from \u88681\uff0c\u88682\uff1b                          ##\u5177\u4f53\u95ee\u9898\u5177\u4f53\u5206\u6790\n<\/code><\/pre>\n\n\n\n
\u591a\u8868\u67e5\u8be2\u5206\u7c7b<\/h3>\n\n\n\n
\u8fde\u63a5\u67e5\u8be2\uff1a<\/strong><\/p>\n\n\n\n
\u5185\u8fde\u63a5\uff1a\u76f8\u5f53\u4e8e\u67e5\u8be2A,B\u4ea4\u96c6\u90e8\u5206\u6570\u636e<\/p>\n\n\n\n
\u5916\u8fde\u63a5\uff1a<\/p>\n\n\n\n
\u5de6\u5916\u8fde\u63a5\uff1a\u67e5\u8be2\u5de6\u8868\u6240\u6709\u6570\u636e\uff0c\u4ee5\u53ca\u4e24\u5f20\u8868\u4ea4\u96c6\u90e8\u5206\u6570\u636e<\/p>\n\n\n\n
\u53f3\u5916\u8fde\u63a5\uff1a\u67e5\u8be2\u53f3\u8868\u6240\u6709\u6570\u636e\uff0c\u4ee5\u53ca\u4e24\u5f20\u8868\u4ea4\u96c6\u90e8\u5206\u6570\u636e<\/p>\n\n\n\n
\u81ea\u8fde\u63a5\uff1a\u5f53\u524d\u8868\u548c\u81ea\u8eab\u8fde\u63a5\u67e5\u8be2\uff0c\u81ea\u8fde\u63a5\u5fc5\u987b\u4f7f\u7528\u8868\u522b\u540d<\/p>\n\n\n\n
\u8fde\u63a5\u67e5\u8be2-\u5185\u8fde\u63a5<\/strong><\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
## \u9690\u5f0f\u5185\u8fde\u63a5\uff0c\u5f53\u6709\u503c\u4e3anull\u7684\u65f6\u5019\uff0c\u4e0d\u4f1a\u663e\u793a\u51fa\u6765\u3002\n\nselect \u5b57\u6bb5\u5217\u8868 from \u88681\uff0c\u88682\uff0cwhere \u6761\u4ef6\uff1b       \n\n## \u663e\u5f0f\u5185\u8fde\u63a5\uff1a\u5f53\u6709\u503c\u4e3anull\u7684\u65f6\u5019\uff0c\u4f1a\u663e\u793a\u51fa\u6765\u3002\n\nselect \u5b57\u6bb5\u5217\u8868 from \u88681 [inner] join \u88682 on \u8fde\u63a5\u6761\u4ef6\uff1b inner\u53ef\u7701\u7565\n<\/code><\/pre>\n\n\n\n
\u8fde\u63a5\u67e5\u8be2-\u5916\u8fde\u63a5<\/strong><\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
## \u5de6\u5916\u8fde\u63a5 \n\nselect \u5b57\u6bb5\u5217\u8868 from \u88681 left [outer] join \u88682 on \u6761\u4ef6\uff1b\n\n## \u76f8\u5f53\u4e8e\u67e5\u8be2\u88681 \u5de6\u8868 \u7684\u6240\u6709\u6570\u636e \u5305\u542b\u88681\u88682\u4ea4\u96c6\u90e8\u5206\u7684\u6570\u636e\n\n## \u53f3\u5916\u8fde\u63a5\n\nselect \u5b57\u6bb5\u5217\u8868 from right [outer] join \u88682 on \u6761\u4ef6\uff1b\n\n## \u76f8\u5f53\u4e8e\u67e5\u8be2\u88682 \u53f3\u8868 \u7684\u6240\u6709\u6570\u636e \u5305\u542b\u88681\u88682\u4ea4\u96c6\u90e8\u5206\u7684\u6570\u636e\n<\/code><\/pre>\n\n\n\n
\u81ea\u8fde\u63a5\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
select \u5b57\u6bb5\u5217\u8868 from \u8868a \u522b\u540da join \u8868a \u522b\u540db on \u6761\u4ef6\uff1b\n\n## \u81ea\u8fde\u63a5\u67e5\u8be2\uff0c\u65e2\u53ef\u4ee5\u662f\u5185\u8fde\u63a5\u67e5\u8be2\uff0c\u4e5f\u53ef\u4ee5\u662f\u5916\u8fde\u63a5\u67e5\u8be2 \u5fc5\u987b\u7ed9\u8868\u53d6\u522b\u540d<\/code><\/pre>\n\n\n\n
\u8054\u5408\u67e5\u8be2-union\uff0cunion all<\/strong><\/p>\n\n\n\n
\u5bf9\u4e8eunion\u67e5\u8be2\uff0c\u5c31\u662f\u5427 \u591a\u6b21\u67e5\u8be2\u7684\u7ed3\u679c\u5408\u5e76\u8d77\u6765\uff0c\u5f62\u6210\u4e00\u4e2a\u65b0\u7684\u67e5\u8be2\u7ed3\u679c\u3002<\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
select \u5b57\u6bb5\u5217\u8868 \u8868a...\n\nunion [all]               ## \u6709all\u4e0d\u53bb\u91cd\uff0c\u6ca1\u6709all\u53bb\u91cd\n\nselect \u5b57\u6bb5\u5217\u8868 from \u8868b...;\n\n## \u5bf9\u4e8e\u8054\u5408\u67e5\u8be2\u7684\u591a\u5f20\u8868\u7684\u5217\u6570\u5fc5\u987b\u4fdd\u6301\u4e00\u81f4\uff0c\u5b57\u6bb5\u7c7b\u578b\u4e5f\u9700\u8981\u4fdd\u6301\u4e00\u81f4\n\n## union all \u4f1a\u5c06\u5168\u90e8\u6570\u636e\u5408\u5728\u4e00\u8d77\uff0cunion\u4f1a\u5bf9\u5408\u5e76\u4e4b\u540e\u7684\u6570\u636e\u53bb\u91cd\u5904\u7406<\/code><\/pre>\n\n\n\n
\u5b50\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u6982\u5ff5\uff1aSQL\u8bed\u53e5\u4e2d\u5d4c\u5957select\u8bed\u53e5\uff0c\u79f0\u4e3a\u5d4c\u5957\u67e5\u8be2\uff0c\u53c8\u79f0\u5b50\u67e5\u8be2<\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
select * from t1 where column1 = (select climn1 from t2)\n##  \u5b50\u67e5\u8be2\u5916\u90e8\u8bed\u53e5\u53ef\u4ee5\u662finsert\/update\/delete\/select \u7684\u4efb\u4f55\u4e00\u4e2a<\/code><\/pre>\n\n\n\n
\u5206\u7c7b\uff1a<\/p>\n\n\n\n
\u6839\u636e\u5b50\u67e5\u8be2\u7ed3\u679c\u4e0d\u540c<\/strong>\uff0c\u5206\u4e3a\uff1a<\/p>\n\n\n\n
\u6807\u91cf\u5b50\u67e5\u8be2\uff08\u5b50\u67e5\u8be2\u7ed3\u679c\u4e3a\u5355\u4e2a\u503c\uff09<\/p>\n\n\n\n
\u5217\u5b50\u67e5\u8be2\uff08\u5b50\u67e5\u8be2\u7ed3\u679c\u4e3a\u4e00\u5217\uff09\u884c\u5b50\u67e5\u8be2\uff08\u5b50\u67e5\u8be2\u7ed3\u679c\u4e3a\u4e00\u884c\uff09<\/p>\n\n\n\n
\u8868\u5b50\u67e5\u8be2\uff08\u5b50\u67e5\u8be2\u7ed3\u679c\u4e3a\u591a\u5217\u591a\u884c\uff09<\/p>\n\n\n\n
\u6839\u636e\u5b50\u67e5\u8be2\u4f4d\u7f6e<\/strong>\uff0c\u5206\u4e3a\uff1a<\/p>\n\n\n\n
where\u4e4b\u540e\uff0cfrom\u4e4b\u524d\uff0cselect\u4e4b\u540e<\/p>\n\n\n\n
\u6807\u91cf\u5b50\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u6982\u5ff5\uff1a\u5b50\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u662f\u5355\u4e2a\u503c\uff08\u6570\u5b57\uff0c\u5b57\u7b26\u4e32\uff0c\u65e5\u671f\u7b49\uff09\uff0c\u6700\u7b80\u5355\u7684\u5f62\u5f0f\uff0c\u8fd9\u79cd\u5b50\u67e5\u8be2\u79f0\u4e3a\u6807\u91cf\u5b50\u67e5\u8be2<\/p>\n\n\n\n
\u5e38\u7528\u7684\u64cd\u4f5c\u7b26\uff1a = <> > >= < <=<\/p>\n\n\n\n
\u5217\u5b50\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u6982\u5ff5\uff1a\u5b50\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u662f\u4e00\u5217\uff08\u53ef\u4ee5\u662f\u591a\u884c\uff09 \uff0c\u8fd9\u79cd\u5b50\u67e5\u8be2\u79f0\u4e3a\u5217\u5b50\u67e5\u8be2<\/p>\n\n\n\n
\u5e38\u7528\u7684\u64cd\u4f5c\u7b26\uff1a in \uff0cnot in \uff0cany\uff0csome\uff0call<\/p>\n\n\n\n
\u64cd\u4f5c\u7b26<\/td>\u63cf\u8ff0<\/td><\/tr>
in<\/td>\u5728\u6307\u5b9a\u7684\u96c6\u5408\u8303\u56f4\u4e4b\u5185\uff0c\u591a\u9009\u4e00 <\/td><\/tr>
not in<\/td>\u4e0d\u5728\u6307\u5b9a\u7684\u96c6\u5408\u8303\u56f4\u4e4b\u5185<\/td><\/tr>
any<\/td>\u5b50\u67e5\u8be2\u8fd4\u56de\u5217\u8868\u4e2d\uff0c\u6709\u4efb\u610f\u4e00\u4e2a\u6ee1\u8db3\u5373\u53ef<\/td><\/tr>
some<\/td>\u4e0eANY\u7b49\u540c\uff0c\u4f7f\u7528SOME\u7684\u5730\u65b9\u90fd\u53ef\u4ee5\u4f7f\u7528ANY<\/td><\/tr>
all<\/td>\u5b50\u67e5\u8be2\u8fd4\u56de\u5217\u8868\u7684\u6240\u6709\u503c\u90fd\u5fc5\u987b\u6ee1\u8db3<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u884c\u5b50\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u6982\u5ff5\uff1a\u5b50\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u662f\u4e00\u884c\uff08\u53ef\u4ee5\u662f\u591a\u5217\uff09\uff0c\u8fd9\u79cd\u5b50\u67e5\u8be2\u79f0\u4e3a\u884c\u5b50\u67e5\u8be2<\/p>\n\n\n\n
\u5e38\u89c1\u7684\u64cd\u4f5c\u7b26\uff1a = \uff0c<>, in, not in<\/p>\n\n\n\n
\u8868\u5b50\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u6982\u5ff5\uff1a\u5b50\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u662f\u591a\u884c\u591a\u5217\uff0c\u8fd9\u79cd\u5b50\u67e5\u8be2\u79f0\u4e3a\u8868\u5b50\u67e5\u8be2\u3002<\/p>\n\n\n\n
\u5e38\u7528\u7684\u64cd\u4f5c\u7b26\uff1ain\uff0c<\/p>\n\n\n\n
\u5f53\u67e5\u8be2\u7684\u7ed3\u679c\u4e3a\u591a\u884c\u7684\u65f6\u5019\uff0c\u4e0d\u80fd\u7528 ‘=’\uff0c\u800c\u662f\u7528 ‘in’\u67e5\u8be2\uff1a<\/p>\n\n\n\n
where (value1,value2) in ()<\/code><\/pre>\n\n\n\n
\u4e8b\u7269<\/h2>\n\n\n\n
\u4e8b\u7269\u7b80\u4ecb\uff1a<\/h3>\n\n\n\n
\u4e8b\u7269\u7b80\u4ecb\uff1a \u662f\u4e00\u7ec4\u64cd\u4f5c\u7684 \u96c6\u5408\uff0c\u5b83\u662f\u4e00\u4e2a\u4e0d\u53ef\u5206\u5272\u7684\u5355\u4f4d\uff0c\u4e8b\u7269\u4f1a\u5427\u6240\u6709\u7684\u64cd\u4f5c\u4f5c\u4e3a\u4e00\u4e2a\u6574\u4f53\u4e00\u8d77\u5411\u7cfb\u7edf\u63d0\u4ea4\u6216\u8005\u64a4\u9500\u64cd\u4f5c\u8bf7\u6c42\uff0c\u5373\u8fd9\u4e9b\u64cd\u4f5c\u8981\u4e48\u540c\u65f6\u6210\u529f\uff0c\u8981\u4e48\u540c\u65f6\u5931\u8d25\u3002<\/p>\n\n\n\n
\u6848\u4f8b\uff1b\u94f6\u884c\u8f6c\u8d26<\/p>\n\n\n\n
\u4e8b\u7269\u64cd\u4f5c<\/h3>\n\n\n\n
\u4e24\u79cd\u65b9\u6cd5<\/strong><\/p>\n\n\n\n
1.\u67e5\u770b\/\u8bbe\u7f6e\u4e8b\u7269\u63d0\u4ea4\u65b9\u5f0f\uff1a\n\nselect @@autocommit;   ## \u67e5\u770b\u4e8b\u7269\u63d0\u4ea4\u65b9\u5f0f =1\u4e3a\u81ea\u52a8\u63d0\u4ea4 =0\u4e3a\u624b\u52a8\u63d0\u4ea4\n\nset @@autocommit=0\n\n2.\u63d0\u4ea4\u4e8b\u52a1\uff1a\n\ncommit\uff1b\n\n##  \u51fa\u73b0\u5f02\u5e38\uff0c\u56de\u6eda\u4e8b\u52a1\n\n3.\u56de\u6eda\u4e8b\u7269\uff1a\n\nrollback\n\n## \u63d0\u4ea4\u4e8b\u52a1\u7684\u65f6\u5019\u51fa\u73b0\u5f02\u5e38\uff0c\u53d1\u73b0\u9519\u8bef\u6ca1\u6709\u63d0\u4ea4\u6210\u529f\uff0c\u6ca1\u6709\u63d0\u4ea4\u6210\u529f\u5c31\u9700\u8981\u56de\u6eda\uff0c\u4fdd\u969c\u6b63\u786e\u6027\u548c\u5b8c\u6574\u6027\u3002\u7b2c\u4e00\u79cd\u65b9\u6cd5 \u4fee\u6539\u4e3a\u624b\u52a8\u63d0\u4ea4\u4e3a0\u7684\u65f6\u5019\uff0c\u8f93\u5165\u8981\u4fee\u6539\u7684\u6307\u4ee4\u540e\uff0c\u9700\u8981\u63d0\u4ea4\u4e8b\u52a1\u8f93\u5165commit\u6307\u4ee4\uff0c\u51fa\u73b0\u5f02\u5e38\u56de\u6eda\n\n## \u5e76\u4e14\u63d0\u4ea4\u4e8b\u52a1\u7684\u65f6\u5019\uff0c\u82e5\u62a5\u9519\uff0c\u90a3\u4e48\u4e00\u6574\u4e2a\u6307\u4ee4\u90fd\u6ca1\u6709\u66f4\u6539\u6570\u636e\n\n## \u82e5\u63d0\u4ea4\u4e8b\u52a1\u540e\uff0c\u6ca1\u6709\u62a5\u9519\uff0c\u4e0d\u9700\u8981\u56de\u6eda<\/code><\/pre>\n\n\n\n
1.\u5f00\u542f\u4e8b\u52a1\n\nstart transaction \u6216\u8005 begin\n\n2 \u63d0\u4ea4\u4e8b\u52a1\uff1a\n\ncommit\uff1b\n\n3. \u56de\u6eda\u4e8b\u7269\uff1a\n\nrollback\n\n##  \u8be5\u65b9\u5f0f\uff1a\n\n##  \u5f00\u542f\u4e8b\u7269\u540e\uff0c\u8f93\u5165\u547d\u4ee4\uff0c\u82e5\u62a5\u9519\uff0c\u5219\u4e0d\u9700\u8981\u8f93\u5165commit\u5f00\u542f\u4e8b\u52a1\uff0c\u76f4\u63a5\u56de\u6eda\u4e8b\u52a1\n\n##  \u82e5\u62a5\u9519\uff0c\u4e5f\u4e0d\u4f1a\u66f4\u6539\u539f\u672c\u6570\u636e\n\n##  \u82e5\u6ca1\u6709\u62a5\u9519\uff0c\u90a3\u4e48\u9700\u8981\u63d0\u4ea4\u4e8b\u52a1commit\uff0c\u4e0d\u9700\u8981\u56de\u6eda<\/code><\/pre>\n\n\n\n
\u4e8b\u7269\u56db\u5927\u7279\u6027<\/h3>\n\n\n\n
\u539f\u5b50\u6027(atomicity)<\/strong>\uff1a\u4e8b\u7269\u662f\u4e0d\u53ef\u5206\u5272\u7684\u6700\u5c0f\u64cd\u4f5c\u5355\u5143\uff0c\u8981\u4e48\u5168\u90e8\u6210\u529f\uff0c\u8981\u4e48\u5168\u90e8\u5931\u8d25\u3002<\/p>\n\n\n\n
\u539f\u5b50\u6027\u6307\u6574\u4e2a\u6570\u636e\u5e93\u4e8b\u7269\u662f\u4e0d\u53ef\u5206\u5272\u7684\u5de5\u4f5c\u5355\u4f4d\u3002\u53ea\u6709\u4f7f\u4e8b\u7269\u4e2d\u6240\u6709\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u90fd\u6267\u884c\u6210\u529f\uff0c\u6574\u4e2a\u4e8b\u7269\u7684\u6267\u884c\u624d\u7b97\u6210\u529f\u3002\u4e8b\u7269\u4e2d\u4efb\u4f55\u4e00\u76f4SQL\u8bed\u53e5\u6267\u884c\u5931\u8d25\uff0c\u90a3\u4e48\u5df2\u7ecf\u6267\u884c\u6210\u529f\u7684SQL\u8bed\u53e5\u4e5f\u5fc5\u987b\u64a4\u9500\uff0c\u6570\u636e\u5e93\u72b6\u6001\u5e94\u8be5\u9000\u56de\u5230\u6267\u884c\u524d\u7684\u72b6\u6001\u3002<\/p>\n\n\n\n
\u4e00\u81f4\u6027(consistency)<\/strong>:\u4e8b\u7269\u5b8c\u6210\u65f6\uff0c\u5fc5\u987b\u4f7f\u6240\u6709\u7684\u6570\u636e\u90fd\u4fdd\u6301\u4e00\u81f4\u72b6\u6001\u3002<\/p>\n\n\n\n
\u4e00\u81f4\u6027\u6307\u4e8b\u7269\u5c06\u6570\u636e\u5e93\u4ece\u4e00\u79cd\u72b6\u6001\u53d8\u4e3a\u53e6\u4e00\u79cd\u72b6\u6001\u3002\u5728\u4e8b\u7269\u5f00\u59cb\u4e4b\u524d\u548c\u4e8b\u7269\u7ed3\u675f\u540e\uff0c\u6570\u636e\u5e93\u7684\u5b8c\u6574\u6027\u7ea6\u675f\u6ca1\u6709\u88ab\u7834\u574f<\/p>\n\n\n\n
\u9694\u79bb\u6027(isolation):<\/strong> \u6570\u636e\u5e93\u7cfb\u7edf\u63d0\u4f9b\u7684\u9694\u79bb\u673a\u5236\uff0c\u4fdd\u8bc1\u4e8b\u7269\u5728\u4e0d\u53d7\u5916\u90e8\u5e76\u53d1\u64cd\u4f5c\u5f71\u54cd\u7684\u72ec\u7acb\u73af\u5883\u4e0b\u8fd0\u884c\u3002\u4e8b\u7269\u7684\u9694\u79bb\u6027\u8981\u6c42\u6bcf\u4e2a\u8bfb\u5199\u4e8b\u7269\u7684\u5bf9\u8c61\u548c\u5176\u4ed6\u4e8b\u7269\u7684\u64cd\u4f5c\u5bf9\u8c61\u80fd\u76f8\u4e92\u5206\u79bb\uff0c\u5373\u8be5\u4e8b\u7269\u63d0\u4ea4\u524d\u5bf9\u5176\u4ed6\u4e8b\u7269\u90fd\u662f\u4e0d\u53ef\u89c1\u7684\uff0c\u8fd9\u901a\u5e38\u7528\u9501\u6765\u5b9e\u73b0<\/p>\n\n\n\n
\u6301\u4e45\u6027(durability):<\/strong>\u4e8b\u7269\u4e00\u65e6\u63d0\u4ea4\u6216\u8005\u56de\u6eda\uff0c\u4ed6\u5bf9\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\u7684\u6539\u53d8\u5c31\u662f\u6c38\u4e45\u7684\u3002<\/p>\n\n\n\n
\u4e8b\u7269\u4e00\u70b9\u63d0\u4ea4\uff0c\u5176\u7ed3\u679c\u5c31\u662f\u6c38\u4e45\u6027\u7684\u3002\u6301\u4e45\u6027\u4fdd\u8bc1\u7684\u4e8b\u7269\u5177\u6709\u9ad8\u53ef\u9760\u6027\uff0c\u800c\u4e0d\u662f\u9ad8\u53ef\u7528\u6027<\/p>\n\n\n\n
\u5e76\u53d1\u4e8b\u7269\u95ee\u9898<\/h3>\n\n\n\n
\u810f\u8bfb \uff1a \u4e00\u4e2a\u4e8b\u7269\u8bfb\u5230\u53e6\u5916\u4e00\u4e2a\u4e8b\u7269\u8fd8\u6ca1\u6709\u63d0\u4ea4\u7684\u6570\u636e\u3002<\/p>\n\n\n\n
\u4e0d\u53ef\u91cd\u590d\u8bfb \uff1a \u4e00\u4e2a\u4e8b\u7269\u5148\u540e\u8bfb\u53d6\u540c\u4e00\u6761\u8bb0\u5f55\uff0c\u4f46\u4e24\u6b21\u8bfb\u53d6\u7684\u6570\u636e\u4e0d\u540c\uff0c\u79f0\u4e4b\u4e3a\u4e0d\u53ef\u91cd\u590d\u8bfb\u3002<\/p>\n\n\n\n
\u5e7b\u8bfb \uff1a \u4e00\u4e2a\u4e8b\u7269\u6309\u7167\u6761\u4ef6\u67e5\u8be2\u6570\u636e\u65f6\uff0c\u6ca1\u6709\u5bf9\u5e94\u7684\u6570\u636e\u884c\uff0c\u4f46\u662f\u5728\u63d2\u5165\u6570\u636e\u65f6\uff0c\u53c8\u53d1\u73b0\u8fd9\u884c\u6570\u636e\u4ee5\u5df2\u7ecf\u8fd0\u884c\uff0c\u597d\u50cf\u51fa\u73b0\u4e86\u5e7b\u5f71\u3002(\u5e7b\u8bfb\u51fa\u73b0\u524d\u63d0\u662f\u89e3\u51b3\u4e86\u4e0d\u53ef\u91cd\u590d\u8bfb\u3002)<\/p>\n\n\n\n
\u4e8b\u7269\u9694\u79bb\u7ea7\u522b<\/h3>\n\n\n\n
\u9694\u79bb\u7ea7\u522b<\/td>\u810f\u8bfb<\/td>\u4e0d\u53ef\u91cd\u590d\u8bfb<\/td>\u5e7b\u8bfb<\/td><\/tr>
read uncommitted<\/td>\u221a<\/td>\u221a<\/td>\u221a<\/td><\/tr>
read committed<\/td>\u00d7<\/td>\u221a<\/td>\u221a<\/td><\/tr>
repeatable read(Datadrip\u9ed8\u8ba4)<\/td>\u00d7<\/td>\u00d7<\/td>\u221a<\/td><\/tr>
serializable<\/td>\u00d7<\/td>\u00d7<\/td>\u00d7<\/td><\/tr><\/tbody><\/table>
\u4ece\u4e0a\u5230\u4e0b\u5b89\u5168\u6027\u8d8a\u6765\u8d8a\u9ad8\uff0c\u4ece\u4e0b\u5230\u4e0a\u6027\u80fd \u8d8a\u6765\u8d8a\u597d<\/figcaption><\/figure>\n\n\n\n
\u67e5\u770b\u4e8b\u7269\u9694\u79bb\u7ea7\u522b<\/strong>\uff1a<\/p>\n\n\n\n
select @@transaction_isolation;<\/code><\/pre>\n\n\n\n
\u8bbe\u7f6e\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\uff1a<\/p>\n\n\n\n
set [session \/global] transaction isolation level [\u9694\u79bb\u7ea7\u522b] \n        \u5f53\u524d\/\u5168\u5c40<\/code><\/pre>\n\n\n\n
\u603b\u7ed3<\/h2>\n\n\n\n
\u4ee5\u4e0a\u662fMySQL\u7684\u57fa\u7840\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
MySQL\u662f\u4e00\u79cd\u5f00\u6e90\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\uff0c\u7531\u745e\u5178MySQL AB\u516c\u53f8\u5f00\u53d1\uff0c\u73b0\u5728\u7531Oracle\u516c\u53f8\u7ef4\u62a4\u3002MyS […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[29],"class_list":["post-27","post","type-post","status-publish","format-standard","hentry","category-mysql","tag-mysql"],"_links":{"self":[{"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/posts\/27","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=27"}],"version-history":[{"count":0,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/posts\/27\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=27"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=27"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=27"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}