{"id":1831,"date":"2024-09-02T23:14:26","date_gmt":"2024-09-02T15:14:26","guid":{"rendered":"https:\/\/www.chencuo.top\/?p=1831"},"modified":"2024-09-02T23:14:26","modified_gmt":"2024-09-02T15:14:26","slug":"mysql-%e8%bf%9b%e9%98%b6%e7%af%87","status":"publish","type":"post","link":"https:\/\/www.chencuo.top\/?p=1831","title":{"rendered":"mysql \u2014\u2014\u8fdb\u9636\u7bc7"},"content":{"rendered":"\n

\u5b58\u50a8\u5f15\u64ce<\/h2>\n\n\n\n

\u89e3\u91ca<\/h3>\n\n\n\n

\u5b58\u50a8\u5f15\u64ce\u5c42\uff0c \u5b58\u50a8\u5f15\u64ce\u771f\u6b63\u7684\u8d1f\u8d23\u4e86MySQL\u4e2d\u6570\u636e\u7684\u5b58\u50a8\u548c\u63d0\u53d6\uff0c\u670d\u52a1\u5668\u901a\u8fc7API\u548c\u5b58\u50a8\u5f15\u64ce\u8fdb\u884c\u901a\u4fe1\u3002\u4e0d\u540c\u7684\u5b58\u50a8\u5f15\u64ce\u5177\u6709\u4e0d\u540c\u7684\u529f\u80fd\uff0c\u8fd9\u6837\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u81ea\u5df1\u7684\u9700\u8981\uff0c\u6765\u9009\u53d6\u5408\u9002\u7684\u5b58\u50a8\u5f15\u64ce\u3002\u6570\u636e\u5e93\u4e2d\u7684\u7d22\u5f15\u662f\u5728\u5b58\u50a8\u5f15\u64ce\u5c42\u5b9e\u73b0\u7684\u3002<\/p>\n\n\n\n

\u57fa\u7840\u4f7f\u7528<\/h3>\n\n\n\n

\u67e5\u8be2\u5efa\u8868\u8bed\u53e5 — \u9ed8\u8ba4\u5b58\u50a8\u5f15\u64ce<\/p>\n\n\n\n

show create table account\uff1b ##\u67e5\u770baccount\u8868\u9ed8\u8ba4\u5f15\u64ce<\/code><\/pre>\n\n\n\n
\u5efa\u8868\u65f6\u6307\u5b9a\u5b58\u50a8\u5f15\u64ce<\/p>\n\n\n\n
CREATE TABLE \u8868\u540d(\n\n\u5b57\u6bb51 \u5b57\u6bb51\u7c7b\u578b [ COMMENT \u5b57\u6bb51\u6ce8\u91ca ] ,\n\n......\n\n\u5b57\u6bb5n \u5b57\u6bb5n\u7c7b\u578b [COMMENT \u5b57\u6bb5n\u6ce8\u91ca ]\n\n) ENGINE = INNODB [ COMMENT \u8868\u6ce8\u91ca ] ;<\/code><\/pre>\n\n\n\n
\u67e5\u8be2\u5f53\u524d\u6570\u636e\u5e93\u652f\u6301\u7684\u5b58\u50a8\u5f15\u64ce<\/p>\n\n\n\n
show engines;<\/code><\/pre>\n\n\n\n
\u5b9e\u4f8b<\/h3>\n\n\n\n
\u4e00\u662f\u5b9e\u4f8b\uff0c\u4e5f\u662f\u4e3a\u540e\u9762\u4ecb\u7ecd\u505a\u94fa\u57ab <\/p>\n\n\n\n
\u521b\u5efa\u8868 my_memory , \u6307\u5b9aMemory\u5b58\u50a8\u5f15\u64ce<\/p>\n\n\n\n
create table my_memory(\n\nid int,\n\nname varchar(10)\n\n) engine = Memory;<\/code><\/pre>\n\n\n\n
\u521b\u5efa\u8868 my_myisam , \u5e76\u6307\u5b9aMyISAM\u5b58\u50a8\u5f15\u64ce<\/p>\n\n\n\n
create table my_myisam(\n\nid int,\n\nname varchar(10)\n\n) engine = MyISAM;<\/code><\/pre>\n\n\n\n
InnoDB<\/h3>\n\n\n\n
InnoDB\u662f\u4e00\u79cd\u517c\u987e\u9ad8\u53ef\u9760\u6027\u548c\u9ad8\u6027\u80fd\u7684\u901a\u7528\u5b58\u50a8\u5f15\u64ce\uff0c\u5728 MySQL 5.5 \u4e4b\u540e\uff0cInnoDB\u662f\u9ed8\u8ba4\u7684 MySQL \u5b58\u50a8\u5f15\u64ce<\/p>\n\n\n\n
\u7279\u70b9<\/strong><\/p>\n\n\n\n
DML\u64cd\u4f5c\u9075\u5faaACID\u6a21\u578b\uff0c\u652f\u6301\u4e8b\u52a1<\/p>\n\n\n\n
\u884c\u7ea7\u9501\uff0c\u63d0\u9ad8\u5e76\u53d1\u8bbf\u95ee\u6027\u80fd<\/p>\n\n\n\n
\u652f\u6301\u5916\u952eFOREIGN KEY\u7ea6\u675f\uff0c\u4fdd\u8bc1\u6570\u636e\u7684\u5b8c\u6574\u6027\u548c\u6b63\u786e\u6027<\/p>\n\n\n\n
\u6587\u4ef6<\/p>\n\n\n\n
xxx.ibd\uff1axxx\u4ee3\u8868\u7684\u662f\u8868\u540d\uff0cinnoDB\u5f15\u64ce\u7684\u6bcf\u5f20\u8868\u90fd\u4f1a\u5bf9\u5e94\u8fd9\u6837\u4e00\u4e2a\u8868\u7a7a\u95f4\u6587\u4ef6\uff0c\u5b58\u50a8\u8be5\u8868\u7684\u8868\u7ed3\u6784\uff08frm-\u65e9\u671f\u7684 \u3001sdi-\u65b0\u7248\u7684\uff09\u3001\u6570\u636e\u548c\u7d22\u5f15<\/p>\n\n\n\n
\u53c2\u6570<\/p>\n\n\n\n
innodb_file_per_table<\/code><\/pre>\n\n\n\n
\u67e5\u770b\u53c2\u6570\u503c\uff0c\u7cfb\u7edf\u53d8\u91cf\uff0c\u67e5\u770b\u662f\u5426\u5f00\u542f \u503c\u4e3a on<\/p>\n\n\n\n
show variables like 'innodb_file_per_table';<\/code><\/pre>\n\n\n\n
\u627e\u5230\u4f60\u521b\u5efa\u7684\u5e93\u2014\u2014\u8868 \u2014\u2014\u8fdb\u5165\u627e\u5230\u4f60\u521b\u5efa\u7684\u8868\uff0c\u82e5\u5b58\u50a8\u5f15\u64ce\u4e3ainnodb\uff0c\u5219ibd\u540e\u7f00\u7ed3\u5c3e<\/p>\n\n\n\n
\u53ef\u4ee5\u770b\u5230\u91cc\u9762\u6709\u5f88\u591a\u7684ibd\u6587\u4ef6\uff0c\u6bcf\u4e00\u4e2aibd\u6587\u4ef6\u5c31\u5bf9\u5e94\u4e00\u5f20\u8868\uff0c\u6bd4\u5982\uff1a\u6211\u4eec\u6709\u4e00\u5f20\u8868 account\uff0c\u5c31\u6709\u8fd9\u6837\u7684\u4e00\u4e2aaccount.ibd\u6587\u4ef6\uff0c\u800c\u5728\u8fd9\u4e2aibd\u6587\u4ef6\u4e2d\u4e0d\u4ec5\u5b58\u653e\u8868\u7ed3\u6784\u3001\u6570\u636e\uff0c\u8fd8\u4f1a\u5b58\u653e\u8be5\u8868\u5bf9\u5e94\u7684\u7d22\u5f15\u4fe1\u606f\u3002 \u800c\u8be5\u6587\u4ef6\u662f\u57fa\u4e8e\u4e8c\u8fdb\u5236\u5b58\u50a8\u7684\uff0c\u4e0d\u80fd\u76f4\u63a5\u57fa\u4e8e\u8bb0\u4e8b\u672c\u6253\u5f00\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528mysql\u63d0\u4f9b\u7684\u4e00\u4e2a\u6307\u4ee4 ibd2sdi \uff0c\u901a\u8fc7\u8be5\u6307\u4ee4\u5c31\u53ef\u4ee5\u4eceibd\u6587\u4ef6\u4e2d\u63d0\u53d6sdi\u4fe1\u606f\uff0c\u800csdi\u6570\u636e\u5b57\u5178\u4fe1\u606f\u4e2d\u5c31\u5305\u542b\u8be5\u8868<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
Memory<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/p>\n\n\n\n
Memory\u5f15\u64ce\u7684\u8868\u6570\u636e\u65f6\u5b58\u50a8\u5728\u5185\u5b58\u4e2d\u7684\uff0c\u7531\u4e8e\u53d7\u5230\u786c\u4ef6\u95ee\u9898\u3001\u6216\u65ad\u7535\u95ee\u9898\u7684\u5f71\u54cd\uff0c\u53ea\u80fd\u5c06\u8fd9\u4e9b\u8868\u4f5c\u4e3a\u4e34\u65f6\u8868\u6216\u7f13\u5b58\u4f7f\u7528<\/p>\n\n\n\n
\u7279\u70b9<\/strong><\/p>\n\n\n\n
\u5185\u5b58\u5b58\u653e<\/p>\n\n\n\n
hash\u7d22\u5f15\uff08\u9ed8\u8ba4\uff09<\/p>\n\n\n\n
\u6587\u4ef6<\/strong><\/p>\n\n\n\n
xxx.sdi\uff1a\u5b58\u50a8\u8868\u7ed3\u6784\u4fe1\u606f<\/p>\n\n\n\n
MyISAM<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
MyISAM\u662fMySQL\u65e9\u671f\u7684\u9ed8\u8ba4\u5b58\u50a8\u5f15\u64ce\u3002<\/p>\n\n\n\n
\u7279\u70b9<\/p>\n\n\n\n
\u4e0d\u652f\u6301\u4e8b\u52a1\uff0c\u4e0d\u652f\u6301\u5916\u952e<\/p>\n\n\n\n
\u652f\u6301\u8868\u9501\uff0c\u4e0d\u652f\u6301\u884c\u9501<\/p>\n\n\n\n
\u8bbf\u95ee\u901f\u5ea6\u5feb<\/p>\n\n\n\n
\u6587\u4ef6<\/p>\n\n\n\n
xxx.sdi\uff1a\u5b58\u50a8\u8868\u7ed3\u6784\u4fe1\u606f<\/p>\n\n\n\n
xxx.MYD: \u5b58\u50a8\u6570\u636e<\/p>\n\n\n\n
xxx.MYI: \u5b58\u50a8\u7d22\u5f15<\/p>\n\n\n\n
\u533a\u522b\u4ee5\u53ca\u7279\u70b9<\/h3>\n\n\n\n
\u7279\u70b9<\/td>InnoDB<\/td>MyISAM<\/td>Memory<\/td><\/tr>
\u5b58\u50a8\u9650\u5236<\/td>64TB<\/td>\u6709<\/td>\u6709<\/td><\/tr>
\u4e8b\u52a1\u5b89\u5168<\/td>\u652f\u6301<\/td>\/<\/td>\/<\/td><\/tr>
\u9501\u673a\u5236<\/td>\u652f\u6301<\/td>\u8868\u9501<\/td>\u8868\u9501<\/td><\/tr>
B+tree\u7d22\u5f15<\/td>\u652f\u6301<\/td>\u652f\u6301<\/td>\u652f\u6301<\/td><\/tr>
Hash\u7d22\u5f15<\/td>\/<\/td>\/<\/td>\u652f\u6301<\/td><\/tr>
\u5168\u6587\u7d22\u5f15<\/td>\u652f\u6301(5.6\u7248\u672c\u4e4b\u540e)<\/td>\u652f\u6301<\/td>\/<\/td><\/tr>
\u7a7a\u95f4\u4f7f\u7528<\/td>\u9ad8<\/td>\u4f4e<\/td>N\/A<\/td><\/tr>
\u5185\u5b58\u4f7f\u7528<\/td>\u9ad8<\/td>\u4f4e<\/td>\u4e2d\u7b49<\/td><\/tr>
\u6279\u91cf\u63d2\u5165\u901f\u5ea6<\/td>\u4f4e<\/td>\u9ad8<\/td>\u9ad8<\/td><\/tr>
\u652f\u6301\u5916\u952e<\/td>\u652f\u6301<\/td>\/<\/td>\/<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u9762\u8bd5\u9898<\/h3>\n\n\n\n
\u9762\u8bd5\u9898<\/p>\n\n\n\n
InnoDB\u5f15\u64ce\u4e0eMyISAM\u5f15\u64ce\u7684\u533a\u522b ? <\/p>\n\n\n\n
\u2460. InnoDB\u5f15\u64ce, \u652f\u6301\u4e8b\u52a1, \u800cMyISAM\u4e0d\u652f\u6301\u3002<\/p>\n\n\n\n
\u2461. InnoDB\u5f15\u64ce, \u652f\u6301\u884c\u9501\u548c\u8868\u9501, \u800cMyISAM\u4ec5\u652f\u6301\u8868\u9501, \u4e0d\u652f\u6301\u884c\u9501\u3002<\/p>\n\n\n\n
\u2462. InnoDB\u5f15\u64ce, \u652f\u6301\u5916\u952e, \u800cMyISAM\u662f\u4e0d\u652f\u6301\u7684\u3002<\/p>\n\n\n\n
\u7d22\u5f15<\/strong><\/h2>\n\n\n\n
\u63d0\u793a\uff1a<\/strong><\/p>\n\n\n\n
\u82e5\u4f60\u53ea\u662f\u4e3a\u4e86\u5b66\u4e60mysql\u7684\u7d22\u5f15\uff0c\u5efa\u8bae\u4ece\u7d22\u5f15\u7684\u5206\u7c7b\u770b\u8d77\uff0c\u524d\u9762\u7684\u53ea\u662f\u6211\u6df1\u6316<\/p>\n\n\n\n
\u7d22\u5f15\u6982\u8ff0<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/h4>\n\n\n\n
\u7d22\u5f15\uff08index\uff09\u662f\u5e2e\u52a9MySQL\u9ad8\u6548\u83b7\u53d6\u6570\u636e\u7684\u6570\u636e\u7ed3\u6784(\u6709\u5e8f)\u3002\u5728\u6570\u636e\u4e4b\u5916\uff0c\u6570\u636e\u5e93\u7cfb\u7edf\u8fd8\u7ef4\u62a4\u7740\u6ee1\u8db3 \u7279\u5b9a\u67e5\u627e\u7b97\u6cd5\u7684\u6570\u636e\u7ed3\u6784\uff0c\u8fd9\u4e9b\u6570\u636e\u7ed3\u6784\u4ee5\u67d0\u79cd\u65b9\u5f0f\u5f15\u7528\uff08\u6307\u5411\uff09\u6570\u636e\uff0c \u8fd9\u6837\u5c31\u53ef\u4ee5\u5728\u8fd9\u4e9b\u6570\u636e\u7ed3\u6784 \u4e0a\u5b9e\u73b0\u9ad8\u7ea7\u67e5\u627e\u7b97\u6cd5\uff0c\u8fd9\u79cd\u6570\u636e\u7ed3\u6784\u5c31\u662f\u7d22\u5f15<\/p>\n\n\n\n
\u6f14\u793a<\/strong><\/h4>\n\n\n\n
\u4f8b\u5982\u6211\u4eec\u9700\u8981\u4f7f\u7528SQL\u8bed\u53e5\u4e3a\uff1a<\/p>\n\n\n\n
select * from user where age = 45<\/p>\n\n\n\n
\u90a3\u4e48\u6570\u636e\u7684\u67e5\u8be2\u5c31\u8981\u4ece\u7b2c\u4e00\u884c\u5f00\u59cb\uff0c\u4e00\u76f4\u626b\u63cf\u5230\u6700\u540e\u4e00\u884c\uff0c\u6211\u4eec\u79f0\u4e4b\u4e3a \u5168\u8868\u626b\u63cf\uff0c\u6027\u80fd\u5f88\u4f4e\u3002<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u800c\u5f53\u6211\u4eec\u6709\u4e86\u7d22\u5f15\uff0c\u5047\u8bbe\u7d22\u5f15\u7ed3\u6784\u5c31\u662f\u4e8c\u53c9\u6811\uff0c\u90a3\u4e48\u4e5f\u5c31\u610f\u5473\u7740\uff0c\u4f1a\u5bf9age\u8fd9\u4e2a\u5b57\u6bb5\u5efa \u7acb\u4e00\u4e2a\u4e8c\u53c9\u6811\u7684\u7d22\u5f15\u7ed3\u6784<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6b64\u65f6\u6211\u4eec\u5728\u8fdb\u884c\u67e5\u8be2\u65f6\uff0c\u53ea\u9700\u8981\u626b\u63cf\u4e09\u6b21\u5c31\u53ef\u4ee5\u627e\u5230\u6570\u636e\u4e86\uff0c\u6781\u5927\u7684\u63d0\u9ad8\u7684\u67e5\u8be2\u7684\u6548\u7387<\/p>\n\n\n\n
\u7279\u70b9<\/h4>\n\n\n\n
\u4f18\u52bf<\/td>\u52a3\u52bf<\/td><\/tr>
\u63d0\u9ad8\u6570\u636e\u68c0\u7d22\u7684\u6548\u7387\uff0c\u964d\u4f4e\u6570\u636e\u5e93 \u7684IO\u6210\u672c<\/td>\u7d22\u5f15\u5217\u4e5f\u662f\u8981\u5360\u7528\u7a7a\u95f4\u7684<\/td><\/tr>
\u901a\u8fc7\u7d22\u5f15\u5217\u5bf9\u6570\u636e\u8fdb\u884c\u6392\u5e8f\uff0c\u964d\u4f4e \u6570\u636e\u6392\u5e8f\u7684\u6210\u672c\uff0c\u964d\u4f4eCPU\u7684\u6d88 \u8017<\/td>\u7d22\u5f15\u5927\u5927\u63d0\u9ad8\u4e86\u67e5\u8be2\u6548\u7387\uff0c\u540c\u65f6\u5374\u4e5f\u964d\u4f4e\u66f4\u65b0\u8868\u7684\u901f\u5ea6\uff0c \u5982\u5bf9\u8868\u8fdb\u884cINSERT\u3001UPDATE\u3001DELETE\u65f6\uff0c\u6548\u7387\u964d\u4f4e<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u7d22\u5f15\u7ed3\u6784<\/strong><\/h3>\n\n\n\n
\u6982\u8ff0<\/h3>\n\n\n\n
MySQL\u7684\u7d22\u5f15\u662f\u5728\u5b58\u50a8\u5f15\u64ce\u5c42\u5b9e\u73b0\u7684\uff0c\u4e0d\u540c\u7684\u5b58\u50a8\u5f15\u64ce\u6709\u4e0d\u540c\u7684\u7d22\u5f15\u7ed3\u6784<\/p>\n\n\n\n
\u7d22\u5f15<\/td>InnoDB<\/td>MyISAM<\/td>Memory<\/td><\/tr>
B+tree\u7d22\u5f15<\/td>\u652f\u6301<\/td>\u652f\u6301<\/td>\u652f\u6301<\/td><\/tr>
Hash \u7d22\u5f15<\/td>\u4e0d\u652f\u6301<\/td>\u4e0d\u652f\u6301<\/td>\u652f\u6301<\/td><\/tr>
R-tree \u7d22\u5f15<\/td>\u4e0d\u652f\u6301<\/td>\u652f\u6301<\/td>\u4e0d\u652f\u6301<\/td><\/tr>
Full-text<\/td>5.6\u7248\u672c\u540e\u652f\u6301<\/td>\u652f\u6301<\/td>\u4e0d\u652f\u6301<\/td><\/tr><\/tbody><\/table>
\u6ce8\u610f\uff1a \u6211\u4eec\u5e73\u5e38\u6240\u8bf4\u7684\u7d22\u5f15\uff0c\u5982\u679c\u6ca1\u6709\u7279\u522b\u6307\u660e\uff0c\u90fd\u662f\u6307B+\u6811\u7ed3\u6784\u7ec4\u7ec7\u7684\u7d22\u5f15<\/figcaption><\/figure>\n\n\n\n
\u6b64\u5904\u4ecb\u7ecd\u4e8c\u53c9\u6811\uff0c\u7ea2\u9ed1\u6811\uff0cbtree\uff0cb+tree\uff0chash\u7ed3\u6784\uff0c\u53ea\u8bf4\u660e\u5728\u6570\u636e\u5e93\u4e2d\u7684\u4f7f\u7528\u65b9\u5f0f\uff0c\u4e0d\u4ecb\u7ecd\u539f\u7406\uff0c\u82e5\u60f3\u8981\u4e86\u89e3\u6811\u7ed3\u6784\uff0c\u53ef\u4ee5\u67e5\u770b\uff1a\u6570\u636e\u7ed3\u6784<\/a><\/p>\n\n\n\n
\u4e8c\u53c9\u6811<\/strong><\/h4>\n\n\n\n
\u8fd9\u91cc\u5047\u5982MySQL\u7684\u7d22\u5f15\u7ed3\u6784\u91c7\u7528\u4e8c\u53c9\u6811\u7684\u6570\u636e\u7ed3\u6784\uff0c\u6bd4\u8f83\u7406\u60f3\u7684\u7ed3\u6784\u5982\u4e0b\uff1a<\/p>\n\n\n\n
\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u63d2\u5165\u7684\u6570\u636e\u662f\u4e0d\u662f\u6309\u7167\u5927\u5c0f\u987a\u5e8f\u63d2\u5165\u6392\u5e8f\u7684(\u6bd4\u8f83\u7406\u60f3\u7684\u7ed3\u6784)<\/p>\n\n\n\n
\u63d2\u5165\u6570\u636e\u4f9d\u6b21\u4e3a\uff1a36,22,33,48,53,19,45,,17,23,20<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u67e5\u770b\u4e0a\u56fe\uff0c\u6211\u4eec\u53d1\u73b0\uff0c\u82e5\u60f3\u8981\u901a\u8fc7\u7d22\u5f15\u627e\u523045,\u4f7f\u7528\u4e8c\u53c9\u6811\uff0c\u7b2c\u4e09\u6b2136\u2014\u201448\u2014\u201445\uff0c\u5373\u53ef\u627e\u523045\uff0c\u4f46\u662f\uff0c\u82e5\u4e0d\u4f7f\u7528\u7d22\u5f15\uff0c\u4f60\u9700\u89817\u6b21\u624d\u80fd\u67e5\u5230<\/p>\n\n\n\n
\u82e5\u4e0d\u662f\u7406\u60f3\u7ed3\u6784\u5462\uff1f<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4e0a\u8ff0\u56fe\uff0c\u7b26\u5408\u4e8c\u53c9\u8868\u7684\u4f7f\u7528\u89c4\u8303\uff0c\u4f46\u4e0d\u662f\u8fd9\u91cc\u6307\u5b9a\u7684\u7406\u60f3\u7ed3\u6784\uff0c\u5b83\u63d2\u5165\u7684\u65f6\u5019\u662f\u6309\u7167\u5927\u5c0f\u987a\u5e8f\u63d2\u5165\u7684\uff0c\u6700\u7ec8\u6210\u4e3a\u4e86\u5355\u94fe\u8868\uff0c\u6700\u7ec8\u7d22\u5f15\u7684\u65f6\u5019\u548c\u4e0d\u4f7f\u7528\u7d22\u5f15\u65e0\u5f02<\/p>\n\n\n\n
\u6240\u4ee5\uff0c\u6211\u4eec\u53ef\u4ee5\u5f97\u5230\u603b\u7ed3\uff0c\u5982\u679c\u9009\u62e9\u4e8c\u53c9\u6811\u4f5c\u4e3a\u7d22\u5f15\u7ed3\u6784\uff0c\u4f1a\u5b58\u5728\u4ee5\u4e0b\u7f3a\u70b9\uff1a<\/p>\n\n\n\n
 \u987a\u5e8f\u63d2\u5165\u65f6\uff0c\u4f1a\u5f62\u6210\u4e00\u4e2a\u94fe\u8868\uff0c\u67e5\u8be2\u6027\u80fd\u5927\u5927\u964d\u4f4e\u3002<\/p>\n\n\n\n
\u5927\u6570\u636e\u91cf\u60c5\u51b5\u4e0b\uff0c\u5c42\u7ea7\u8f83\u6df1\uff0c\u68c0\u7d22\u901f\u5ea6\u6162<\/p>\n\n\n\n
\u7ea2\u9ed1\u6811<\/strong><\/h4>\n\n\n\n
\u90a3\u4e48\u6b64\u5904\u6211\u4eec\u5c31\u4f1a\u60f3\u5230\u7ea2\u9ed1\u6811\uff0c\u56e0\u4e3a\u7ea2\u9ed1\u6811\u662f\u4e00\u9897\u81ea\u5e73\u8861\u4e8c\u53c9\u6811\uff0c\u5373\u4f7f\u662f\u987a\u5e8f\u63d2\u5165\u6570 \u636e\uff0c\u6700\u7ec8\u5f62\u6210\u7684\u6570\u636e\u7ed3\u6784\u4e5f\u662f\u4e00\u9897\u5e73\u8861\u7684\u4e8c\u53c9\u6811<\/p>\n\n\n\n
\u8fd9\u91cc\u4f7f\u7528\u4e00\u6837\u7684\u6570\u636e\uff1a36,22,33,48,53,19,45,,17,23,20\uff0c\u8003\u8651\u5927\u5c0f\u987a\u5e8f\u987a\u5e8f\u63d2\u5165<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4f46\u662f\uff0c\u5373\u4f7f\u5982\u6b64\uff0c\u7531\u4e8e\u7ea2\u9ed1\u6811\u4e5f\u662f\u4e00\u9897\u4e8c\u53c9\u6811\uff0c\u6240\u4ee5\u4e5f\u4f1a\u5b58\u5728\u4e00\u4e2a\u7f3a\u70b9\uff1a <\/p>\n\n\n\n
\u5927\u6570\u636e\u91cf\u60c5\u51b5\u4e0b\uff0c\u5c42\u7ea7\u8f83\u6df1\uff0c\u68c0\u7d22\u901f\u5ea6\u6162\u3002<\/p>\n\n\n\n
\u6700\u540e\uff0c\u6211\u4eec\u5f97\u5230\uff1a<\/p>\n\n\n\n
\u5728MySQL\u7684\u7d22\u5f15\u7ed3\u6784\u4e2d\uff0c\u5e76\u6ca1\u6709\u9009\u62e9\u4e8c\u53c9\u6811\u6216\u8005\u7ea2\u9ed1\u6811\uff0c\u800c\u9009\u62e9\u7684\u662fB+Tree<\/p>\n\n\n\n
B-Tree<\/h4>\n\n\n\n
\u7b80\u4ecb<\/strong><\/p>\n\n\n\n
B-Tree\uff0cB\u6811\u662f\u4e00\u79cd\u591a\u53c9\u8def\u8861\u67e5\u627e\u6811\uff0c\u76f8\u5bf9\u4e8e\u4e8c\u53c9\u6811\uff0cB\u6811\u6bcf\u4e2a\u8282\u70b9\u53ef\u4ee5\u6709\u591a\u4e2a\u5206\u652f\uff0c\u5373\u591a\u53c9\u3002<\/p>\n\n\n\n
 \u4ee5\u4e00\u9897\u6700\u5927\u5ea6\u6570\uff08max-degree\uff09\u4e3a5(5\u9636)\u7684b-tree\u4e3a\u4f8b\uff0c\u90a3\u8fd9\u4e2aB\u6811\u6bcf\u4e2a\u8282\u70b9\u6700\u591a\u5b58\u50a84\u4e2akey\uff0c5\u4e2a\u6307\u9488\u3002<\/p>\n\n\n\n
\u540c\u7406\uff0c\u4ee5\u6700\u5927\u5ea6\u6570\u4e3a4(4\u9636)\uff0c\u5219\u8be5b\u6811\u6bcf\u4e2a\u8282\u70b9\u6700\u591a\u50a8\u5b583\u4e2akey\uff0c4\u4e2a\u6307\u9488\u3002<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7279\u70b9<\/strong><\/p>\n\n\n\n
5\u9636\u7684B\u6811\uff0c\u6bcf\u4e00\u4e2a\u8282\u70b9\u6700\u591a\u5b58\u50a84\u4e2akey\uff0c\u5bf9\u5e945\u4e2a\u6307\u9488<\/p>\n\n\n\n
 \u4e00\u65e6\u8282\u70b9\u5b58\u50a8\u7684key\u6570\u91cf\u5230\u8fbe5\uff0c\u5c31\u4f1a\u88c2\u53d8\uff0c\u4e2d\u95f4\u5143\u7d20\u5411\u4e0a\u5206\u88c2<\/p>\n\n\n\n
 \u5728B\u6811\u4e2d\uff0c\u975e\u53f6\u5b50\u8282\u70b9\u548c\u53f6\u5b50\u8282\u70b9\u90fd\u4f1a\u5b58\u653e\u6570\u636e<\/p>\n\n\n\n
B+Tree<\/strong><\/h4>\n\n\n\n
B+Tree\u662fB-Tree\u7684\u53d8\u79cd\uff0c\u6211\u4eec\u4ee5\u4e00\u9897\u6700\u5927\u5ea6\u6570\uff08max-degree\uff09\u4e3a4\uff084\u9636\uff09\u7684b+tree\u4e3a\u4f8b\uff0c\u6765\u770b\u4e00 \u4e0b\u5176\u7ed3\u6784\u793a\u610f\u56fe<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7279\u70b9\uff1a<\/p>\n\n\n\n
\u7eff\u8272\u6846\u6846\u8d77\u6765\u7684\u90e8\u5206\uff0c\u662f\u7d22\u5f15\u90e8\u5206\uff0c\u4ec5\u4ec5\u8d77\u5230\u7d22\u5f15\u6570\u636e\u7684\u4f5c\u7528\uff0c\u4e0d\u5b58\u50a8\u6570\u636e<\/p>\n\n\n\n
\u7ea2\u8272\u6846\u6846\u8d77\u6765\u7684\u90e8\u5206\uff0c\u662f\u6570\u636e\u5b58\u50a8\u90e8\u5206\uff0c\u5728\u5176\u53f6\u5b50\u8282\u70b9\u4e2d\u8981\u5b58\u50a8\u5177\u4f53\u7684\u6570\u636e<\/p>\n\n\n\n
\u6700\u7ec8\u6211\u4eec\u770b\u5230\uff0cB+Tree \u4e0e B-Tree\u76f8\u6bd4\uff0c\u4e3b\u8981\u6709\u4ee5\u4e0b\u4e09\u70b9\u533a\u522b<\/p>\n\n\n\n
B+tree\u6240\u6709\u7684\u6570\u636e\u90fd\u4f1a\u51fa\u73b0\u5728\u53f6\u5b50\u8282\u70b9<\/p>\n\n\n\n
B+tree\u53f6\u5b50\u8282\u70b9\u5f62\u6210\u4e00\u4e2a\u5355\u5411\u94fe\u8868<\/p>\n\n\n\n
B+tree\u975e\u53f6\u5b50\u8282\u70b9\u4ec5\u4ec5\u8d77\u5230\u7d22\u5f15\u6570\u636e\u4f5c\u7528\uff0c\u5177\u4f53\u7684\u6570\u636e\u90fd\u662f\u5728\u53f6\u5b50\u8282\u70b9\u5b58\u653e\u7684<\/p>\n\n\n\n
mysql\u6807\u51c6\u5316<\/strong><\/p>\n\n\n\n
\u4e0a\u8ff0\u6211\u4eec\u6240\u770b\u5230\u7684\u7ed3\u6784\u662f\u6807\u51c6\u7684B+Tree\u7684\u6570\u636e\u7ed3\u6784\uff0c\u518d\u6765\u770b\u770bMySQL\u4e2d\u4f18\u5316\u4e4b\u540e\u7684B+Tree<\/p>\n\n\n\n
MySQL\u7d22\u5f15\u6570\u636e\u7ed3\u6784\u5bf9\u7ecf\u5178\u7684B+Tree\u8fdb\u884c\u4e86\u4f18\u5316\u3002\u5728\u539fB+Tree\u7684\u57fa\u7840\u4e0a\uff0c\u589e\u52a0\u4e00\u4e2a\u6307\u5411\u76f8\u90bb\u53f6\u5b50\u8282\u70b9 \u7684\u94fe\u8868\u6307\u9488\uff0c\u5c31\u5f62\u6210\u4e86\u5e26\u6709\u987a\u5e8f\u6307\u9488\u7684B+Tree\uff0c\u63d0\u9ad8\u533a\u95f4\u8bbf\u95ee\u7684\u6027\u80fd\uff0c\u5229\u4e8e\u6392\u5e8f<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
Hash<\/strong><\/h4>\n\n\n\n
\u7ed3\u6784<\/strong><\/p>\n\n\n\n
\u54c8\u5e0c\u7d22\u5f15\u5c31\u662f\u91c7\u7528\u4e00\u5b9a\u7684hash\u7b97\u6cd5\uff0c\u5c06\u952e\u503c\u6362\u7b97\u6210\u65b0\u7684hash\u503c\uff0c\u6620\u5c04\u5230\u5bf9\u5e94\u7684\u69fd\u4f4d\u4e0a\uff0c\u7136\u540e\u5b58\u50a8\u5728<\/p>\n\n\n\n
hash\u8868\u4e2d<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4f46\u662f\uff0c\u5982\u679c\u4e24\u4e2a(\u6216\u591a\u4e2a)\u952e\u503c\uff0c\u6620\u5c04\u5230\u4e00\u4e2a\u76f8\u540c\u7684\u69fd\u4f4d\u4e0a\uff0c\u4ed6\u4eec\u5c31\u4ea7\u751f\u4e86hash\u51b2\u7a81\uff08\u4e5f\u79f0\u4e3ahash\u78b0\u649e\uff09\uff0c\u8fd9\u4e2a\u95ee\u9898\u53ef\u4ee5\u901a\u8fc7\u94fe\u8868\u6765\u89e3\u51b3\uff0c\u5982\u7ea2\u9ed1\u6811<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7279\u70b9<\/strong><\/p>\n\n\n\n
Hash\u7d22\u5f15\u53ea\u80fd\u7528\u4e8e\u5bf9\u7b49\u6bd4\u8f83(=\uff0cin)\uff0c\u4e0d\u652f\u6301\u8303\u56f4\u67e5\u8be2\uff08between\uff0c>\uff0c< \uff0c…\uff09<\/p>\n\n\n\n
 \u65e0\u6cd5\u5229\u7528\u7d22\u5f15\u5b8c\u6210\u6392\u5e8f\u64cd\u4f5c<\/p>\n\n\n\n
\u67e5\u8be2\u6548\u7387\u9ad8\uff0c\u901a\u5e38(\u4e0d\u5b58\u5728hash\u51b2\u7a81\u7684\u60c5\u51b5)\u53ea\u9700\u8981\u4e00\u6b21\u68c0\u7d22\u5c31\u53ef\u4ee5\u4e86\uff0c\u6548\u7387\u901a\u5e38\u8981\u9ad8\u4e8eB+tree\u7d22\u5f15<\/p>\n\n\n\n
\u5b58\u50a8\u5f15\u64ce\u652f\u6301<\/strong><\/p>\n\n\n\n
\u5728MySQL\u4e2d\uff0c\u652f\u6301hash\u7d22\u5f15\u7684\u662fMemory\u5b58\u50a8\u5f15\u64ce\uff0c\u800c\u5728InnoDB\u4e2d\uff0c\u6709\u81ea\u9002\u5e94hash\u7d22\u5f15\u7684\u529f\u80fd\uff0chash\u7d22\u5f15\u662fInnoDB\u5b58\u50a8\u5f15\u64ce\u6839\u636eB+Tree\u7d22\u5f15\u5728\u6307\u5b9a\u6761\u4ef6\u4e0b\u81ea\u52a8\u6784\u5efa\u7684<\/p>\n\n\n\n
\u9762\u8bd5\u9898<\/strong><\/h4>\n\n\n\n
\u4e3a\u4ec0\u4e48InnoDB\u5b58\u50a8\u5f15\u64ce\u9009\u62e9\u4f7f\u7528B+tree\u7d22\u5f15\u7ed3\u6784?<\/p>\n\n\n\n
\u76f8\u5bf9\u4e8e\u4e8c\u53c9\u6811\uff0c\u5c42\u7ea7\u66f4\u5c11\uff0c\u641c\u7d22\u6548\u7387\u9ad8\uff1b<\/p>\n\n\n\n
\u5bf9\u4e8eB-tree\uff0c\u65e0\u8bba\u662f\u53f6\u5b50\u8282\u70b9\u8fd8\u662f\u975e\u53f6\u5b50\u8282\u70b9\uff0c\u90fd\u4f1a\u4fdd\u5b58\u6570\u636e\uff0c\u8fd9\u6837\u5bfc\u81f4\u4e00\u9875\u4e2d\u5b58\u50a8 \u7684\u952e\u503c\u51cf\u5c11\uff0c\u6307\u9488\u8ddf\u7740\u51cf\u5c11\uff0c\u8981\u540c\u6837\u4fdd\u5b58\u5927\u91cf\u6570\u636e\uff0c\u53ea\u80fd\u589e\u52a0\u6811\u7684\u9ad8\u5ea6\uff0c\u5bfc\u81f4\u6027\u80fd\u964d\u4f4e\uff1b<\/p>\n\n\n\n
\u76f8\u5bf9Hash\u7d22\u5f15\uff0cB+tree\u652f\u6301\u8303\u56f4\u5339\u914d\u53ca\u6392\u5e8f\u64cd\u4f5c<\/p>\n\n\n\n
\u7d22\u5f15\u5206\u7c7b<\/strong><\/h3>\n\n\n\n
\u7d22\u5f15\u5206\u7c7b<\/strong><\/h4>\n\n\n\n
\u5728MySQL\u6570\u636e\u5e93\uff0c\u5c06\u7d22\u5f15\u7684\u5177\u4f53\u7c7b\u578b\u4e3b\u8981\u5206\u4e3a\u4ee5\u4e0b\u51e0\u7c7b\uff1a\u4e3b\u952e\u7d22\u5f15\u3001\u552f\u4e00\u7d22\u5f15\u3001\u5e38\u89c4\u7d22\u5f15\u3001\u5168\u6587\u7d22\u5f15<\/p>\n\n\n\n
\u5206\u7c7b<\/td>\u542b\u4e49<\/td>\u7279\u70b9<\/td>\u5173\u952e\u8bcd<\/td><\/tr>
\u4e3b\u952e\u7d22\u5f15<\/td>\u9488\u5bf9\u4e8e\u8868\u4e2d\u4e3b\u952e\u521b\u5efa\u7684\u7d22\u5f15<\/td>\u9ed8\u8ba4\u81ea\u52a8\u521b\u5efa\uff0c\u6700\u591a\u53ea\u6709\u4e00\u4e2a<\/td>primary<\/td><\/tr>
\u552f\u4e00\u7d22\u5f15<\/td>\u907f\u514d\u540c\u4e00\u4e2a\u8868\u4e2d\u67d0\u6570\u636e\u5217\u4e2d\u7684\u503c\u91cd\u590d<\/td>\u53ef\u4ee5\u6709\u591a\u4e2a<\/td>unique<\/td><\/tr>
\u5e38\u89c4\u7d22\u5f15<\/td>\u5feb\u901f\u5b9a\u4f4d\u7279\u5b9a\u6570\u636e<\/td>\u53ef\u4ee5\u6709\u591a\u4e2a<\/td><\/td><\/tr>
\u5168\u6587\u7d22\u5f15<\/td>\u5168\u6587\u7d22\u5f15\u67e5\u627e\u7684\u662f\u6587\u672c\u4e2d\u7684\u5173\u952e\u8bcd\uff0c\u800c\u4e0d\u662f\u6bd4 \u8f83\u7d22\u5f15\u4e2d\u7684\u503c<\/td>\u53ef\u4ee5\u6709\u591a\u4e2a<\/td>fulltext<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u805a\u96c6\u7d22\u5f15&\u4e8c\u7ea7\u7d22\u5f15<\/strong><\/h4>\n\n\n\n
\u5728InnoDB\u5b58\u50a8\u5f15\u64ce\u4e2d\uff0c\u6839\u636e\u7d22\u5f15\u7684\u5b58\u50a8\u5f62\u5f0f\uff0c\u53c8\u53ef\u4ee5\u5206\u4e3a\u4ee5\u4e0b\u4e24<\/p>\n\n\n\n
\u5206\u7c7b<\/td>\u542b\u4e49<\/td>\u7279\u70b9<\/td><\/tr>
\u805a\u96c6\u7d22\u5f15(Clustered Index)<\/td>\u5c06\u6570\u636e\u5b58\u50a8\u4e0e\u7d22\u5f15\u653e\u5230\u4e86\u4e00\u5757\uff0c\u7d22\u5f15\u7ed3\u6784\u7684\u53f6\u5b50 \u8282\u70b9\u4fdd\u5b58\u4e86\u884c\u6570\u636e<\/td>\u5fc5\u987b\u6709,\u800c\u4e14\u53ea \u6709\u4e00\u4e2a<\/td><\/tr>
\u4e8c\u7ea7\u7d22\u5f15(Secondary Index)<\/td>\u5c06\u6570\u636e\u4e0e\u7d22\u5f15\u5206\u5f00\u5b58\u50a8\uff0c\u7d22\u5f15\u7ed3\u6784\u7684\u53f6\u5b50\u8282\u70b9\u5173 \u8054\u7684\u662f\u5bf9\u5e94\u7684\u4e3b\u952e<\/td>\u53ef\u4ee5\u5b58\u5728\u591a\u4e2a<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u805a\u96c6\u7d22\u5f15\u9009\u53d6\u89c4\u5219<\/strong><\/p>\n\n\n\n
\u5982\u679c\u5b58\u5728\u4e3b\u952e\uff0c\u4e3b\u952e\u7d22\u5f15\u5c31\u662f\u805a\u96c6\u7d22\u5f15\u3002<\/p>\n\n\n\n
\u5982\u679c\u4e0d\u5b58\u5728\u4e3b\u952e\uff0c\u5c06\u4f7f\u7528\u7b2c\u4e00\u4e2a\u552f\u4e00\uff08UNIQUE\uff09\u7d22\u5f15\u4f5c\u4e3a\u805a\u96c6\u7d22\u5f15\u3002 <\/p>\n\n\n\n
\u5982\u679c\u8868\u6ca1\u6709\u4e3b\u952e\uff0c\u6216\u6ca1\u6709\u5408\u9002\u7684\u552f\u4e00\u7d22\u5f15\uff0c\u5219InnoDB\u4f1a\u81ea\u52a8\u751f\u6210\u4e00\u4e2arowid\u4f5c\u4e3a\u9690\u85cf\u7684\u805a\u96c6\u7d22\u5f15<\/p>\n\n\n\n
\u805a\u96c6\u7d22\u5f15\u548c\u4e8c\u7ea7\u7d22\u5f15\u7684\u5177\u4f53\u7ed3\u6784\uff0c\u91c7\u7528\u7684\u662fB+tree<\/strong><\/p>\n\n\n\n
\u805a\u96c6\u7d22\u5f15\u7684\u53f6\u5b50\u8282\u70b9\u4e0b\u6302\u7684\u662f\u8fd9\u4e00\u884c\u7684\u6570\u636e \uff0c\u5982\u4e3b\u952e\u503c\u4e3a5\uff0c\u5305\u542b\uff1aid\uff0cname\uff0cgender<\/p>\n\n\n\n
\u4e8c\u7ea7\u7d22\u5f15\u7684\u53f6\u5b50\u8282\u70b9\u4e0b\u6302\u7684\u662f\u8be5\u5b57\u6bb5\u503c\u5bf9\u5e94\u7684\u4e3b\u952e\u503c\uff0c\u53ea\u5305\u542b\u4e3b\u952e\u503c<\/p>\n\n\n\n
\u4f8b\u5982\uff0c\u5f53\u6211\u4eec\u6267\u884c\u6b64SQL\u8bed\u53e5\u65f6\uff0c\u5176\u8fc7\u7a0b\u4e3a<\/p>\n\n\n\n
select * from user where name =’Arm’<\/p>\n\n\n\n
\u7531\u4e8e\u662f\u6839\u636ename\u5b57\u6bb5\u8fdb\u884c\u67e5\u8be2\uff0c\u6240\u4ee5\u5148\u6839\u636ename=’Arm’\u5230name\u5b57\u6bb5\u7684\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u8fdb\u884c\u5339\u914d\u67e5 \u627e\u3002\u4f46\u662f\u5728\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u53ea\u80fd\u67e5\u627e\u5230 Arm \u5bf9\u5e94\u7684\u4e3b\u952e\u503c 10.\u6b64\u5904\u6211\u4eec\u9700\u8981\u8fdb\u884c\u56de\u8868\u67e5\u8be2\uff0c\u56de\u5230\u805a\u96c6\u7d22\u5f15.<\/p>\n\n\n\n
\u7531\u4e8e\u67e5\u8be2\u8fd4\u56de\u7684\u6570\u636e\u662f*\uff0c\u6240\u4ee5\u6b64\u65f6\uff0c\u8fd8\u9700\u8981\u6839\u636e\u4e3b\u952e\u503c10\uff0c\u5230\u805a\u96c6\u7d22\u5f15\u4e2d\u67e5\u627e10\u5bf9\u5e94\u7684\u8bb0\u5f55\uff0c\u6700\u7ec8\u627e\u523010\u5bf9\u5e94\u7684\u884crow\uff0c\u6700\u540e\u5f97\u5230\u6539\u884c\u7684\u5168\u90e8\u6570\u636e.<\/p>\n\n\n\n
\u56de\u8868\u67e5\u8be2<\/strong><\/p>\n\n\n\n
 \u8fd9\u79cd\u5148\u5230\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u67e5\u627e\u6570\u636e\uff0c\u627e\u5230\u4e3b\u952e\u503c\uff0c\u7136\u540e\u518d\u5230\u805a\u96c6\u7d22\u5f15\u4e2d\u6839\u636e\u4e3b\u952e\u503c\uff0c\u83b7\u53d6 \u6570\u636e\u7684\u65b9\u5f0f\uff0c\u5c31\u79f0\u4e4b\u4e3a\u56de\u8868\u67e5\u8be2<\/p>\n\n\n\n
\u7d22\u5f15\u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
\u521b\u5efa\u7d22\u5f15<\/strong><\/p>\n\n\n\n
create [ unique | fulltext ] index index_name on table_name ( \nindex_col_name,... );<\/code><\/pre>\n\n\n\n
\u67e5\u770b\u7d22\u5f15<\/strong><\/p>\n\n\n\n
show index from table_name;<\/code><\/pre>\n\n\n\n
\u5220\u9664\u7d22\u5f15<\/strong><\/p>\n\n\n\n
drop index index_name on table_name;<\/code><\/pre>\n\n\n\n
\u5b9e\u4f8b<\/strong><\/p>\n\n\n\n
\u4f8b\u5982\u73b0\u5728\u6709\u4e00\u5f20\u8868\u540d\u4e3atb_user\uff0c\u5176\u5b57\u6bb5\u5206\u522b\u6709\uff1aname, phone, email, profession, age, gender, status, createtime<\/p>\n\n\n\n
\u90a3\u4e48\u6211\u4eec\u9700\u8981\u5b8c\u6210\u4ee5\u4e0b\u9700\u6c42\uff1a<\/p>\n\n\n\n
1.name\u5b57\u6bb5\u4e3a\u59d3\u540d\u5b57\u6bb5\uff0c\u8be5\u5b57\u6bb5\u7684\u503c\u53ef\u80fd\u4f1a\u91cd\u590d\uff0c\u4e3a\u8be5\u5b57\u6bb5\u521b\u5efa\u7d22\u5f15<\/p>\n\n\n\n
create index index_name on tb_user(name)<\/code><\/pre>\n\n\n\n
2.phone\u624b\u673a\u53f7\u5b57\u6bb5\u7684\u503c\uff0c\u662f\u975e\u7a7a\uff0c\u4e14\u552f\u4e00\u7684\uff0c\u4e3a\u8be5\u5b57\u6bb5\u521b\u5efa\u552f\u4e00\u7d22\u5f15<\/p>\n\n\n\n
create unique index index_phone on tb_user(phone)<\/code><\/pre>\n\n\n\n
3.\u4e3aprofession\u3001age\u3001status\u521b\u5efa\u8054\u5408\u7d22\u5f15<\/p>\n\n\n\n
create index  index_profession_age_status on tb_user(profession,age,status)<\/code><\/pre>\n\n\n\n
4.\u4e3aemail\u5efa\u7acb\u5408\u9002\u7684\u7d22\u5f15\u6765\u63d0\u5347\u67e5\u8be2\u6548\u7387<\/p>\n\n\n\n
create index index_email on  tb_user(email);<\/code><\/pre>\n\n\n\n
\u7d22\u5f15\u4f7f\u7528<\/strong><\/h3>\n\n\n\n
\u9a8c\u8bc1\u7d22\u5f15\u6548\u7387<\/strong><\/h4>\n\n\n\n
select * from tb_sku where id = 1\\G;\n\u7c7b\u4f3c\u754c\u9762\u5c40\u90e8\u4f18\u5316\uff0c\u53ea\u80fdmysql\u670d\u52a1\u7aef\u4f7f\u7528\uff0c\u56fe\u5f62\u5316\u754c\u9762\u7528\u4e0d\u4e86<\/code><\/pre>\n\n\n\n
\u5f53\u4f60\u4f7f\u7528\u539f\u8868\u67e5\u8be21000W\u6761\u6570\u636e\u7684\u65f6\u5019\uff0c\u4f60\u4f1a\u53d1\u73b0\u76f4\u63a5\u4f7f\u7528\u67e5\u8be2\u8bed\u53e5\uff0c\u67e5\u8be2\u7684\u975e\u5e38\u7f13\u6162\uff0c\u8fd9\u4e2a\u65f6\u5019\u5c31\u9700\u8981\u5efa\u7acb\u7d22\u5f15\uff0c\u5f53\u4f60\u4e0d\u5efa\u8868\u67e5\u8be2\uff0c\u53ef\u80fd\u9700\u898140s\uff0c\u5f53\u4f60\u5efa\u8868\u540e\u67e5\u8be2\uff0c\u53ef\u80fd\u53ea\u9700\u89811\u79d2\u3002<\/p>\n\n\n\n
\u6700\u5de6\u524d\u7f00\u6cd5\u5219<\/strong><\/h4>\n\n\n\n
\u6cd5\u5219<\/strong><\/p>\n\n\n\n
\u5982\u679c\u7d22\u5f15\u4e86\u591a\u5217\uff08\u8054\u5408\u7d22\u5f15\uff09\uff0c\u8981\u9075\u5b88\u6700\u5de6\u524d\u7f00\u6cd5\u5219\u3002<\/p>\n\n\n\n
\u6700\u5de6\u524d\u7f00\u6cd5\u5219\u6307\u7684\u662f\u67e5\u8be2\u4ece\u7d22\u5f15\u7684\u6700\u5de6\u5217\u5f00\u59cb\uff0c\u5e76\u4e14\u4e0d\u8df3\u8fc7\u7d22\u5f15\u4e2d\u7684\u5217\u3002\u5982\u679c\u8df3\u8dc3\u67d0\u4e00\u5217\uff0c\u7d22\u5f15\u5c06\u4f1a\u8be5\u90e8\u5206\u5931\u6548(\u540e\u9762\u7684\u5b57\u6bb5\u7d22\u5f15\u5931\u6548)\uff1a<\/strong>\u4f8b\u5982profession\uff0cage\uff0cstatus\uff0c\u8df3\u8fc7age\uff0c\u7d22\u5f15profession\uff0cstatus\uff0c\u5c31\u4e0d\u4f1a\u7d22\u5f15age\u90e8\u5206\uff0c\u5373\u8be5\u90e8\u5206\u5931\u6548\uff0c\u8df3\u8fc7status\u90e8\u5206\u540c\u6837\u9053\u7406\uff0c\u4f46\u662f\u65e0\u8bba\u5982\u4f55\uff0c\u90fd\u5fc5\u987b\u8981\u6709profession\u7d22\u5f15\u5b57\u6bb5\uff0c\u5373\u6700\u5de6\u5217\u3002<\/p>\n\n\n\n
\u901a\u8fc7\u5b9e\u4f8b\u6f14\u793a\u5176\u7279\u70b9<\/p>\n\n\n\n
\u5728 tb_user \u8868\u4e2d\uff0c\u6709\u4e00\u4e2a\u8054\u5408\u7d22\u5f15\uff0c\u8fd9\u4e2a\u8054\u5408\u7d22\u5f15\u6d89\u53ca\u5230\u4e09\u4e2a\u5b57\u6bb5\uff0c\u987a\u5e8f\u5206\u522b\u4e3a\uff1aprofession\uff0c<\/p>\n\n\n\n
age\uff0cstatus\uff0c\u901a\u8fc7\u4e0b\u56fe\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u67e5\u8be2\u7684key_len\u503c\u4e3a54\uff0c\uff0c\u4f7f\u7528\u4e86\u2018index_profession_age_status\u2019\u8fd9\u4e2a\u8054\u5408\u7d22\u5f15\u3002\uff0c\u4e0d\u4e00\u4e00\u5728\u4e0b\u9762\u5c55\u793a\uff0cprofession\u7684key\u503c\u4e3a47\uff0cage\u4e3a2\uff0cstatus\u4e3a5\uff0c<\/p>\n\n\n\n
\u2019<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6700\u5de6\u5217\uff0c\u4e0d\u610f\u5473\u7740\u5728\u6700\u5de6\u8fb9\uff0c\u6700\u5de6\u5217\u5728\u6700\u53f3\u8fb9\u4e5f\u53ef\u4ee5\uff0c\u53ef\u4ee5\u4ea4\u6362\u4f4d\u7f6e\uff0c\u4f46\u662f\u5fc5\u987b\u6709\u8be5\u5b57\u6bb5<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u8303\u56f4\u67e5\u8be2<\/strong><\/h4>\n\n\n\n
\u8054\u5408\u7d22\u5f15\u4e2d\uff0c\u51fa\u73b0\u8303\u56f4\u67e5\u8be2(>,<)\uff0c\u8303\u56f4\u67e5\u8be2\u53f3\u4fa7\u7684\u5217\u7d22\u5f15\u5931\u6548\u3002\u6b64\u5904age\u662f\u8303\u56f4\u67e5\u8be2\uff1aage>20,\u6240\u4ee5status\u7d22\u5f15\u5931\u6548<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u800c\u5728\u987a\u5e8f\u98a0\u5012\u540e\uff0c\u5982\u4e0b\u56fe\uff0c\u90a3\u4e48\u8303\u56f4\u67e5\u8be2\u5de6\u4fa7\u5217\u7d22\u5f15\u5931\u6548<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u800c\u5f53\u4f7f\u7528>=  \u6216\u8005<= \u7684\u65f6\u5019\uff0c\u65e0\u8bba\u6700\u5de6\u5217\u5728\u5de6\u5728\u53f3\uff0c\u7d22\u5f15\u90fd\u4e0d\u5931\u6548\u3002\u6240\u4ee5\uff0c\u5728\u4e1a\u52a1\u5141\u8bb8\u7684\u60c5\u51b5\u4e0b\uff0c\u5c3d\u53ef\u80fd\u7684\u4f7f\u7528\u7c7b\u4f3c\u4e8e >= \u6216 <= \u8fd9\u7c7b\u7684\u8303\u56f4\u67e5\u8be2\uff0c\u800c\u907f\u514d\u4f7f\u7528 > \u6216 <<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7d22\u5f15\u5931\u6548\u60c5\u51b5<\/strong><\/h4>\n\n\n\n
\u5728\u7d22\u5f15\u5217\u4e0a\u8fdb\u884c\u8fd0\u7b97\u64cd\u4f5c\uff0c \u7d22\u5f15\u5c06\u5931\u6548<\/strong><\/h5>\n\n\n\n
\u5f53dcl\u6839\u636ephone\u5b57\u6bb5\u8fdb\u884c\u7b49\u503c\u67e5\u8be2\uff0c\u7d22\u5f15\u6b63\u5e38<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5f53dcl\u6839\u636ephone\u5b57\u6bb5\u8fdb\u884c\u51fd\u6570\u8fd0\u884c\uff0c\u7d22\u5f15\u5931\u6548\uff0c\u8fd9\u91cc\u4ee5\u622a\u53d6\u4e3a\u4f8b\uff0c\u53ef\u89c1\u7d22\u5f15\u5931\u6548<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5b57\u7b26\u4e32\u4e0d\u52a0\u5f15\u53f7<\/strong><\/h5>\n\n\n\n
\u5f53\u7d22\u5f15\u503c\u4e3a\u5b57\u7b26\u4e32\uff0c\u4f46\u662f\u5b57\u7b26\u4e32\u7684\u503c\u6ca1\u6709\u52a0\u5f15\u53f7\uff0c\u7d22\u5f15\u4e5f\u4f1a\u5931\u6548\uff0c\u770b\u56fe\u53ef\u77e5\uff0ckey_len\u53ea\u670949\uff0c\u5f97\u51fastatus\u7684\u7d22\u5f15\u5931\u6548\u4e86<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5982\u679c\u5b57\u7b26\u4e32\u4e0d\u52a0\u5355\u5f15\u53f7\uff0c\u5bf9\u4e8e\u67e5\u8be2\u7ed3\u679c\uff0c\u6ca1\u4ec0\u4e48\u5f71\u54cd\uff0c\u4f46\u662f\u6570\u636e\u5e93\u5b58\u5728\u9690\u5f0f\u7c7b\u578b\u8f6c\u6362\uff0c\u7d22\u5f15\u5c06\u5931\u6548<\/p>\n\n\n\n
\u6a21\u7cca\u67e5\u8be2<\/strong><\/h5>\n\n\n\n
\u5982\u679c\u4ec5\u4ec5\u662f\u5c3e\u90e8\u6a21\u7cca\u5339\u914d\uff0c\u7d22\u5f15\u4e0d\u4f1a\u5931\u6548\u3002\u5982\u679c\u662f\u5934\u90e8\u6a21\u7cca\u5339\u914d\uff0c\u7d22\u5f15\u5931\u6548<\/p>\n\n\n\n
\u4ece\u4ee5\u4e0b\u4e09\u4e2a\u4f8b\u5b50\u5c55\u793a\uff1a’\u8f6f\u4ef6\u5de5\u7a0b’<\/p>\n\n\n\n
\u2018\u8f6f\u4ef6%\u2019<\/p>\n\n\n\n
\u2018%\u5de5\u7a0b\u2019<\/p>\n\n\n\n
\u2018%\u5de5%\u2019<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5728like\u6a21\u7cca\u67e5\u8be2\u4e2d\uff0c\u5728\u5173\u952e\u5b57\u540e\u9762\u52a0%\uff0c\u7d22\u5f15\u53ef\u4ee5\u751f\u6548\u3002\u800c\u5982\u679c\u5728\u5173\u952e\u5b57\u524d\u9762\u52a0\u4e86%\uff0c\u7d22\u5f15\u5c06\u4f1a\u5931\u6548\uff0c\u800c\u524d\u540e\u90fd\u52a0\u4e86%\u4f9d\u7136\u5931\u6548<\/p>\n\n\n\n
or\u8fde\u63a5\u6761\u4ef6<\/strong><\/h5>\n\n\n\n
\u7528or\u5206\u5272\u5f00\u7684\u6761\u4ef6\uff0c \u5982\u679cor\u524d\u7684\u6761\u4ef6\u4e2d\u7684\u5217\u6709\u7d22\u5f15\uff0c\u800c\u540e\u9762\u7684\u5217\u4e2d\u6ca1\u6709\u7d22\u5f15\uff0c\u90a3\u4e48\u6d89\u53ca\u7684\u7d22\u5f15\u90fd\u4e0d\u4f1a\u88ab\u7528\u5230<\/p>\n\n\n\n
\u4ece\u4e0b\u56fe\u53ef\u5f97\uff0cid\u4e3a\u4e3b\u952e\u7d22\u5f15\uff0c\u4f46\u662fage\u65e0\u7d22\u5f15\uff0c\u6240\u4ee5\u7d22\u5f15\u5931\u6548<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6570\u636e\u5206\u5e03\u5f71\u54cd<\/strong><\/h5>\n\n\n\n
\u5728mysql\u8bc4\u4f30\u4f7f\u7528\u7d22\u5f15\u6bd4\u5168\u8868\u66f4\u6162\uff0c\u5219\u4e0d\u4f7f\u7528\u7d22\u5f15\uff0c\u901a\u5e38\u5728\u5c0f\u8868\u5185<\/p>\n\n\n\n
\u56e0\u4e3aMySQL\u5728\u67e5\u8be2\u65f6\uff0c\u4f1a\u8bc4\u4f30\u4f7f\u7528\u7d22\u5f15\u7684\u6548\u7387\u4e0e\u8d70\u5168\u8868\u626b\u63cf\u7684\u6548\u7387\uff0c\u5982\u679c\u8d70\u5168\u8868\u626b\u63cf\u66f4\u5feb\uff0c\u5219\u653e\u5f03\u7d22\u5f15\uff0c\u8d70\u5168\u8868\u626b\u63cf\u3002 \u56e0\u4e3a\u7d22\u5f15\u662f\u7528\u6765\u7d22\u5f15\u5c11\u91cf\u6570\u636e\u7684\uff0c\u5982\u679c\u901a\u8fc7\u7d22\u5f15\u67e5\u8be2\u8fd4\u56de\u5927\u6279\u91cf\u7684\u6570\u636e\uff0c\u5219\u8fd8\u4e0d\u5982\u8d70\u5168\u8868\u626b\u63cf\u6765\u7684\u5feb\uff0c\u6b64\u65f6\u7d22\u5f15\u5c31\u4f1a\u5931\u6548\uff0c\u4f8b\u5982\u60f3\u8981\u67e5\u770b\u8868\u7684\u5168\u90e8\u6570\u636e\uff0c\u90a3\u4e48\u80af\u5b9a\u662f\u9009\u62e9\u5168\u8868\u626b\u63cf\uff0c<\/p>\n\n\n\n
\u8fd9\u91cc\u4ee5null\uff0cnot null\u4e3a\u4f8b\uff0c\u82e5\u8bbe\u7f6e\u8868\u7684profession\u503c\u4e3anull\uff0cprofession\u7684\u8054\u5408\u7d22\u5f15\u8fd8\u5728\uff0c\u90a3\u4e48\u6211\u5728\u6b64\u5904\u67e5\u8be2profession\u7684\u6570\u636e\u662f\u5426\u4e3anull\uff0c\u90a3\u4e48\u5c31\u4f1a\u4f7f\u7528\u5168\u8868\u626b\u63cf\uff0c\u800c\u4e0d\u662f\u7d22\u5f15\uff0c\u76f8\u53cd\uff0c\u82e5\u6211\u67e5\u8be2profession\u7684\u503c\u662f\u5426\u4e3anot null\uff0c\u90a3\u4e48\u5c31\u4f1a\u4f7f\u7528\u7d22\u5f15<\/p>\n\n\n\n
SQL\u63d0\u793a<\/strong><\/h4>\n\n\n\n
SQL\u63d0\u793a\uff0c\u662f\u4f18\u5316\u6570\u636e\u5e93\u7684\u4e00\u4e2a\u91cd\u8981\u624b\u6bb5\uff0c\u7b80\u5355\u6765\u8bf4\uff0c\u5c31\u662f\u5728SQL\u8bed\u53e5\u4e2d\u52a0\u5165\u4e00\u4e9b\u4eba\u4e3a\u7684\u63d0\u793a\u6765\u8fbe\u5230\u4f18\u5316\u64cd\u4f5c\u7684\u76ee\u7684<\/p>\n\n\n\n
\u4f8b\u5982\u6211\u4eec\u4e3aprofession\u521b\u5efa\u5355\u7d22\u5f15\uff0c\u8fd9\u65f6\u5019profession\u5c31\u6709\u4e24\u4e2a\u7d22\u5f15\u4e86\uff0c\u4e00\u4e2a\u662f\u2018tb_user_profession\u2019\u7684\u5355\u7d22\u5f15\uff0c\u4e00\u4e2a\u662f’tb_user_profession_age_status\u2019\u7684\u8054\u5408\u7d22\u5f15(\u590d\u5408\u7d22\u5f15)\uff0c\u800c\u6570\u636e\u5e93\u4f1a\u9ed8\u8ba4\u9009\u62e9\u6700\u4f18\u7684\u4e00\u4e2a\u7d22\u5f15\uff0c\u4f46\u662f\u6211\u4eec\u53ef\u4ee5\u6307\u5b9a\u7d22\u5f15\u7c7b\u578b<\/p>\n\n\n\n
explain select * from tb_user use index(\u7d22\u5f15\u7c7b\u578b) where \u6761\u4ef6;     ##\u4ec5\u4ec5\u5efa\u8bae\uff0cmysql\u8fd8\u4f1a\u81ea\u884c\u8bc4\u4f30\nexplain select * from tb_user ignore index(\u7d22\u5f15\u7c7b\u578b) where \u6761\u4ef6   ##\u5ffd\u7565\u6307\u5b9a\u7d22\u5f15\uff0c\u5373\u4e0d\u7528\u67d0\u4e2a\u7d22\u5f15\nexplain select * from tb_user enforce index(\u7d22\u5f15\u7c7b\u578b) where \u6761\u4ef6  ##\u5f3a\u5236\u6307\u5b9a\u4f7f\u7528\u7d22\u5f15<\/code><\/pre>\n\n\n\n
\u8986\u76d6\u7d22\u5f15<\/strong><\/h4>\n\n\n\n
\u5c3d\u91cf\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\uff0c\u51cf\u5c11select *\u3002 \u90a3\u4e48\u4ec0\u4e48\u662f\u8986\u76d6\u7d22\u5f15\u5462\uff1f \u8986\u76d6\u7d22\u5f15\u662f\u6307\u67e5\u8be2\u4f7f\u7528\u4e86\u7d22\u5f15\uff0c\u5e76\u4e14\u8be5\u7d22\u5f15\u9700\u8981\u8fd4\u56de\u7684\u5217\uff0c\u5728\u8be5\u7d22\u5f15\u4e2d\u5df2\u7ecf\u5168\u90e8\u80fd\u591f\u627e\u5230<\/p>\n\n\n\n
\u5982select id, profession\uff1a\u901a\u8fc7\u4e8c\u7ea7\u67e5\u8be2profession\u627e\u5230\u4e86id\u503c\uff0c\u8986\u76d6\u67e5\u8be2<\/p>\n\n\n\n
\u5982select id,profession,age, status\uff0c\u901a\u8fc7\u4e8c\u7ea7profession\u8054\u5408\u67e5\u8be2\uff0c\u627e\u5230\u4e86profession,age, status\uff0c\u8986\u76d6\u67e5\u8be2\u627e\u5230id<\/p>\n\n\n\n
\u4f46\u662f\u5982select id,profession,age, status\uff0cname\uff0c\u6b64\u5904\u901a\u8fc7\u4e8c\u7ea7\u67e5\u8be2profession\uff0c\u627e\u5230profession,age, status\uff0c\u901a\u8fc7\u4e8c\u7ea7\u67e5\u8be2\u627e\u5230\u4e86\u4e3b\u952e\u7d22\u5f15id\uff0c\u4f46\u662f\u5e76\u6ca1\u6709\u5728\u8be5\u7d22\u5f15\u4e2d\u627e\u5230\u5168\u90e8\u503c\uff0c\u8fdb\u884c\u56de\u8868\u67e5\u8be2\u81f3\u805a\u5408\u67e5\u8be2\uff0c\u6700\u540e\u67e5\u8be2\u5230name<\/p>\n\n\n\n
\u6ce8\u610f\uff0c\u8986\u76d6\u67e5\u8be2\u65f6\uff0c\u82e5\u6709\u591a\u4e2a\u7d22\u5f15\uff0c\u4e3b\u952e\u9ed8\u8ba4\u4e3a\u805a\u5408\u67e5\u8be2\uff0c\u4e8c\u7ea7\u67e5\u8be2\u6839\u636emysql\u81ea\u884c\u4f18\u5316\u9009\u62e9\u6700\u4f18\uff0c\u82e5\u901a\u8fc7\u8f93\u5165\u547d\u4ee4\uff0c\u5176\u5b9e\u53ef\u4ee5\u770b\u5230\u4e0a\u8ff0\u4e09\u6761\u533a\u522b\u5728\u4e8eextra<\/p>\n\n\n\n
extra<\/td>\u542b\u4e49<\/td><\/tr>
Using where; UsingIndex<\/td>\u67e5\u627e\u4f7f\u7528\u4e86\u7d22\u5f15\uff0c\u4f46\u662f\u9700\u8981\u7684\u6570\u636e\u90fd\u5728\u7d22\u5f15\u5217\u4e2d\u80fd\u627e\u5230\uff0c\u6240\u4ee5\u4e0d\u9700\u8981\u56de\u8868\u67e5\u8be2\u6570\u636e<\/td><\/tr>
Using indexcondition<\/td>\u67e5\u627e\u4f7f\u7528\u4e86\u7d22\u5f15\uff0c\u4f46\u662f\u9700\u8981\u56de\u8868\u67e5\u8be2\u6570\u636e<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u524d\u7f00\u7d22\u5f15<\/strong><\/h4>\n\n\n\n
\u5f53\u5b57\u6bb5\u7c7b\u578b\u4e3a\u5b57\u7b26\u4e32\uff08varchar\uff0ctext\uff0clongtext\u7b49\uff09\u65f6\uff0c\u6709\u65f6\u5019\u9700\u8981\u7d22\u5f15\u5f88\u957f\u7684\u5b57\u7b26\u4e32\uff0c\u8fd9\u4f1a\u8ba9\u7d22\u5f15\u53d8\u5f97\u5f88\u5927\uff0c\u67e5\u8be2\u65f6\uff0c\u6d6a\u8d39\u5927\u91cf\u7684\u78c1\u76d8IO\uff0c \u5f71\u54cd\u67e5\u8be2\u6548\u7387\u3002\u6b64\u65f6\u53ef\u4ee5\u53ea\u5c06\u5b57\u7b26\u4e32\u7684\u4e00\u90e8\u5206\u524d\u7f00\uff0c\u5efa\u7acb\u7d22\u5f15\uff0c\u8fd9\u6837\u53ef\u4ee5\u5927\u5927\u8282\u7ea6\u7d22\u5f15\u7a7a\u95f4\uff0c\u4ece\u800c\u63d0\u9ad8\u7d22\u5f15\u6548\u7387<\/p>\n\n\n\n
\u524d\u7f00\u957f\u5ea6<\/strong><\/h5>\n\n\n\n
\u90a3\u4e48\u5982\u4f55\u9009\u62e9\u524d\u7f00\u957f\u5ea6\uff0c\u53ef\u4ee5\u6839\u636e\u7d22\u5f15\u7684\u9009\u62e9\u6027\u6765\u51b3\u5b9a\uff0c\u800c\u9009\u62e9\u6027\u662f\u6307\u4e0d\u91cd\u590d\u7684\u7d22\u5f15\u503c\uff08\u57fa\u6570\uff09\u548c\u6570\u636e\u8868\u7684\u8bb0\u5f55\u603b\u6570\u7684\u6bd4\u503c\uff0c\u7d22\u5f15\u9009\u62e9\u6027\u8d8a\u9ad8\u5219\u67e5\u8be2\u6548\u7387\u8d8a\u9ad8\uff0c \u552f\u4e00\u7d22\u5f15\u7684\u9009\u62e9\u6027\u662f1\uff0c\u8fd9\u662f\u6700\u597d\u7684\u7d22\u5f15\u9009\u62e9\u6027\uff0c\u6027\u80fd\u4e5f\u662f\u6700\u597d\u7684<\/p>\n\n\n\n
select  count(distinct \u5b57\u6bb5\u540d) \/ count(*)   from  \u8868\u540d ;\nselect  count(distinct substring(\u5b57\u6bb5\u540d,1,5)) \/ count(*)  from  \u8868\u540dr ;<\/code><\/pre>\n\n\n\n
\u521b\u5efa\u524d\u7f00\u7d22\u5f15<\/strong><\/h5>\n\n\n\n
create index  \u7d22\u5f15\u540d on \u8868\u540d(\u5b57\u6bb5(\u524d\u7f00\u957f\u5ea6)) ;<\/code><\/pre>\n\n\n\n
\u524d\u7f00\u7d22\u5f15\u7684\u67e5\u8be2\u6d41\u7a0b<\/strong><\/h5>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5355\u5217\u7d22\u5f15\u4e0e\u8054\u5408\u7d22\u5f15<\/strong><\/h4>\n\n\n\n
\u5355\u5217\u7d22\u5f15<\/strong>\uff1a\u5373\u4e00\u4e2a\u7d22\u5f15\u53ea\u5305\u542b\u5355\u4e2a\u5217<\/p>\n\n\n\n
\u8054\u5408\u7d22\u5f15<\/strong>\uff1a\u5373\u4e00\u4e2a\u7d22\u5f15\u5305\u542b\u4e86\u591a\u4e2a\u5217<\/p>\n\n\n\n
\u5f53\u6211\u4eec\u4f7f\u7528\u5355\u5217\u7d22\u5f15\u67e5\u8be2\u7684\u65f6\u5019\uff0c\u82e5\u540c\u65f6\u67e5\u8be2age\uff0cstatus\u4e24\u4e2a\u5b57\u6bb5\uff0c\u5047\u8bbe\u5176\u4e3a\u5355\u5217\u7d22\u5f15\uff0c\u6b64\u65f6mysql\u4f1a\u9009\u62e9\u6700\u4f18\u7684\u4e00\u4e2a\u8fdb\u884c\u67e5\u8be2\uff0c\u4f46\u662f\u6700\u540e\u90fd\u9700\u8981\u8fdb\u884c\u56de\u8868\u67e5\u8be2<\/p>\n\n\n\n
\u800c\u5f53\u6211\u4eec\u4f7f\u7528\u8054\u5408\u7d22\u5f15\u7684\u65f6\u5019\uff0c\u82e5\u67e5\u8be2\u7684\u5b57\u6bb5\u4e3a\u8054\u5408\u7d22\u5f15\u5185\u5305\u542b\u7684\u5b57\u6bb5\uff0c\u90a3\u4e48\u5c31\u4f1a\u8986\u76d6\u7d22\u5f15\uff0c\u4e0d\u9700\u8981\u56de\u8868\u67e5\u8be2<\/p>\n\n\n\n
\u8054\u5408\u67e5\u8be2\u56fe\u793a<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7d22\u5f15\u8bbe\u8ba1\u539f\u5219<\/strong><\/h3>\n\n\n\n
1.\u9488\u5bf9\u4e8e\u6570\u636e\u91cf\u8f83\u5927\uff0c\u4e14\u67e5\u8be2\u6bd4\u8f83\u9891\u7e41\u7684\u8868\u5efa\u7acb\u7d22\u5f15<\/p>\n\n\n\n
2. \u9488\u5bf9\u4e8e\u5e38\u4f5c\u4e3a\u67e5\u8be2\u6761\u4ef6\uff08where\uff09\u3001\u6392\u5e8f\uff08order by\uff09\u3001\u5206\u7ec4\uff08group by\uff09\u64cd\u4f5c\u7684\u5b57\u6bb5\u5efa\u7acb\u7d22\u5f15<\/p>\n\n\n\n
3. \u5c3d\u91cf\u9009\u62e9\u533a\u5206\u5ea6\u9ad8\u7684\u5217\u4f5c\u4e3a\u7d22\u5f15\uff0c\u5c3d\u91cf\u5efa\u7acb\u552f\u4e00\u7d22\u5f15\uff0c\u533a\u5206\u5ea6\u8d8a\u9ad8\uff0c\u4f7f\u7528\u7d22\u5f15\u7684\u6548\u7387\u8d8a\u9ad8<\/p>\n\n\n\n
4. \u5982\u679c\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\u7684\u5b57\u6bb5\uff0c\u5b57\u6bb5\u7684\u957f\u5ea6\u8f83\u957f\uff0c\u53ef\u4ee5\u9488\u5bf9\u4e8e\u5b57\u6bb5\u7684\u7279\u70b9\uff0c\u5efa\u7acb\u524d\u7f00\u7d22\u5f15<\/p>\n\n\n\n
5. \u5c3d\u91cf\u4f7f\u7528\u8054\u5408\u7d22\u5f15\uff0c\u51cf\u5c11\u5355\u5217\u7d22\u5f15\uff0c\u67e5\u8be2\u65f6\uff0c\u8054\u5408\u7d22\u5f15\u5f88\u591a\u65f6\u5019\u53ef\u4ee5\u8986\u76d6\u7d22\u5f15\uff0c\u8282\u7701\u5b58\u50a8\u7a7a\u95f4\uff0c\u907f\u514d\u56de\u8868\uff0c\u63d0\u9ad8\u67e5\u8be2\u6548\u7387<\/p>\n\n\n\n
6. \u8981\u63a7\u5236\u7d22\u5f15\u7684\u6570\u91cf\uff0c\u7d22\u5f15\u5e76\u4e0d\u662f\u591a\u591a\u76ca\u5584\uff0c\u7d22\u5f15\u8d8a\u591a\uff0c\u7ef4\u62a4\u7d22\u5f15\u7ed3\u6784\u7684\u4ee3\u4ef7\u4e5f\u5c31\u8d8a\u5927\uff0c\u4f1a\u5f71\u54cd\u589e\u5220\u6539\u7684\u6548\u7387<\/p>\n\n\n\n
7. \u5982\u679c\u7d22\u5f15\u5217\u4e0d\u80fd\u5b58\u50a8NULL\u503c\uff0c\u8bf7\u5728\u521b\u5efa\u8868\u65f6\u4f7f\u7528NOT NULL\u7ea6\u675f\u5b83\u3002\u5f53\u4f18\u5316\u5668\u77e5\u9053\u6bcf\u5217\u662f\u5426\u5305\u542b<\/p>\n\n\n\n
NULL\u503c\u65f6\uff0c\u5b83\u53ef\u4ee5\u66f4\u597d\u5730\u786e\u5b9a\u54ea\u4e2a\u7d22\u5f15\u6700\u6709\u6548\u5730\u7528\u4e8e\u67e5\u8be2\u3002<\/p>\n\n\n\n
SQL\u6027\u80fd\u4f18\u5316<\/strong><\/h2>\n\n\n\n
SQL\u6267\u884c\u9891\u7387<\/strong><\/h3>\n\n\n\n
MySQL \u5ba2\u6237\u7aef\u8fde\u63a5\u6210\u529f\u540e\uff0c\u901a\u8fc7 show [session|global] status \u547d\u4ee4\u53ef\u4ee5\u63d0\u4f9b\u670d\u52a1\u5668\u72b6\u6001\u4fe1 \u606f\u3002\u901a\u8fc7\u5982\u4e0b\u6307\u4ee4\uff0c\u53ef\u4ee5\u67e5\u770b\u5f53\u524d\u6570\u636e\u5e93\u7684INSERT\u3001UPDATE\u3001DELETE\u3001SELECT\u7684\u8bbf\u95ee\u9891\u6b21<\/p>\n\n\n\n
show [session|global] status like 'Com_______';   ##\u4e03\u4e2a\u4e0b\u5212\u7ebf\nsession:\u5c40\u90e8     global:\u5168\u5c40    'Com_' \u56fa\u5b9a\u683c\u5f0f\uff0c\u6b63\u5219\u8868\u8fbe\u5f0f\uff0c\u67e5\u8be2\u7b26\u5408\u6b64\u683c\u5f0f\u7684\u5168\u90e8\u6570\u636e <\/code><\/pre>\n\n\n\n
\u90e8\u5206\u6570\u636e\u89e3\u91ca<\/p>\n\n\n\n
Com_delete: \u5220\u9664\u6b21\u6570<\/p>\n\n\n\n
Com_insert: \u63d2\u5165\u6b21\u6570<\/p>\n\n\n\n
Com_select: \u67e5\u8be2\u6b21\u6570<\/p>\n\n\n\n
Com_update: \u66f4\u65b0\u6b21\u6570<\/p>\n\n\n\n
\u6ce8\u610f\uff1a\u901a\u8fc7\u4e0a\u8ff0\u6307\u4ee4\uff0c\u6211\u4eec\u53ef\u4ee5\u67e5\u770b\u5230\u5f53\u524d\u6570\u636e\u5e93\u5230\u5e95\u662f\u4ee5\u67e5\u8be2\u4e3a\u4e3b\uff0c\u8fd8\u662f\u4ee5\u589e\u5220\u6539\u4e3a\u4e3b\uff0c\u4ece\u800c\u4e3a\u6570\u636e \u5e93\u4f18\u5316\u63d0\u4f9b\u53c2\u8003\u4f9d\u636e\u3002 \u5982\u679c\u662f\u4ee5\u589e\u5220\u6539\u4e3a\u4e3b\uff0c\u6211\u4eec\u53ef\u4ee5\u8003\u8651\u4e0d\u5bf9\u5176\u8fdb\u884c\u7d22\u5f15\u7684\u4f18\u5316\u3002 \u5982\u679c\u662f\u4ee5 \u67e5\u8be2\u4e3a\u4e3b\uff0c\u90a3\u4e48\u5c31\u8981\u8003\u8651\u5bf9\u6570\u636e\u5e93\u7684\u7d22\u5f15\u8fdb\u884c\u4f18\u5316\u4e86<\/p>\n\n\n\n
\u6162\u67e5\u8be2\u65e5\u5fd7<\/strong><\/h3>\n\n\n\n
\u6211\u4eec\u5df2\u7ecf\u77e5\u9053\u4e86\u5728\u67e5\u8be2\u7684\u65f6\u5019\uff0c\u6700\u597d\u5bf9\u6570\u636e\u5e93\u7684\u7d22\u5f15\u8fdb\u884c\u4f18\u5316\uff0c\u6162\u67e5\u8be2\u65e5\u5fd7\u8bb0\u5f55\u4e86\u6240\u6709\u6267\u884c\u65f6\u95f4\u8d85\u8fc7\u6307\u5b9a\u53c2\u6570\uff08long_query_time\uff0c\u5355\u4f4d\uff1a\u79d2\uff0c\u9ed8\u8ba410\u79d2\uff09\u7684\u6240\u6709SQL\u8bed\u53e5\u7684\u65e5\u5fd7<\/p>\n\n\n\n
MySQL\u7684\u6162\u67e5\u8be2\u65e5\u5fd7\u9ed8\u8ba4\u6ca1\u6709\u5f00\u542f\uff0c\u6211\u4eec\u53ef\u4ee5\u67e5\u770b\u4e00\u4e0b\u7cfb\u7edf\u53d8\u91cf slow_query_log<\/p>\n\n\n\n
show variables like 'slow_query_log'\n## \u82e5\u4e3aoff\u9700\u8981\u8fdb\u884c\u4e0b\u9762\u64cd\u4f5c\uff0c\u82e5\u4e3aon\u5219\u5df2\u5f00\u542f<\/code><\/pre>\n\n\n\n
\u7136\u540e\u518d\u914d\u7f6e\u6587\u4ef6\u914d\u7f6e\u4ee5\u4e0b\u5185\u5bb9\uff1awindow\u5728my.ini\uff0clinux\u5728mysql.conf<\/p>\n\n\n\n
# \u5f00\u542fMySQL\u6162\u65e5\u5fd7\u67e5\u8be2\u5f00\u5173\n\nslow_query_log=1\n\n# \u8bbe\u7f6e\u6162\u65e5\u5fd7\u7684\u65f6\u95f4\u4e3a2\u79d2\uff0cSQL\u8bed\u53e5\u6267\u884c\u65f6\u95f4\u8d85\u8fc72\u79d2\uff0c\u5c31\u4f1a\u89c6\u4e3a\u6162\u67e5\u8be2\uff0c\u8bb0\u5f55\u6162\u67e5\u8be2\u65e5\u5fd7\n\nlong_query_time=2<\/code><\/pre>\n\n\n\n
\u67e5\u8be2\u65e5\u5fd7\uff1a<\/p>\n\n\n\n
 tail -f \/var\/lib\/mysql\/localhost-slow.log<\/code><\/pre>\n\n\n\n
profile\u8be6\u60c5<\/strong><\/h3>\n\n\n\n
show profiles \u80fd\u591f\u5728\u505aSQL\u4f18\u5316\u65f6\u5e2e\u52a9\u6211\u4eec\u4e86\u89e3\u65f6\u95f4\u90fd\u8017\u8d39\u5230\u54ea\u91cc\u53bb<\/p>\n\n\n\n
\u67e5\u770b\u5f53\u524d\u7248\u672c\u80fd\u5426\u652f\u6301profiling<\/p>\n\n\n\n
select @@have_profiling;<\/code><\/pre>\n\n\n\n
\u67e5\u770b\u5f53\u524dprofile\u7ea7\u522b<\/p>\n\n\n\n
select @@profiling;<\/code><\/pre>\n\n\n\n
\u8bbe\u7f6eprofile\u7ea7\u522b<\/p>\n\n\n\n
set profiling = 1;<\/code><\/pre>\n\n\n\n
\u901a\u8fc7\u5982\u4e0b\u6307\u4ee4\u67e5\u770b\u6307\u4ee4\u7684\u6267\u884c\u8017\u65f6<\/strong><\/p>\n\n\n\n
-- \u67e5\u770b\u6bcf\u4e00\u6761SQL\u7684\u8017\u65f6\u57fa\u672c\u60c5\u51b5\n\nshow profiles;\n\n-- \u67e5\u770b\u6307\u5b9aquery_id\u7684SQL\u8bed\u53e5\u5404\u4e2a\u9636\u6bb5\u7684\u8017\u65f6\u60c5\u51b5\n\nshow profile for query query_id;\n\n-- \u67e5\u770b\u6307\u5b9aquery_id\u7684SQL\u8bed\u53e5CPU\u7684\u4f7f\u7528\u60c5\u51b5\n\nshow profile cpu for query query_id;<\/code><\/pre>\n\n\n\n
explain<\/strong><\/h3>\n\n\n\n
explain\u53ef\u4ee5\u7528\u6765\u67e5\u770b\u5728mysql\u4e2dselect\u5982\u4f55\u6267\u884cselect\u8bed\u53e5\uff0c\u4ee5\u53ca\u5305\u62ec\u5728select\u8bed\u53e5\u6267\u884c \u8fc7\u7a0b\u4e2d\u8868\u5982\u4f55\u8fde\u63a5\u548c\u8fde\u63a5\u7684\u987a\u5e8f<\/p>\n\n\n\n
-- \u76f4\u63a5\u5728select\u8bed\u53e5\u4e4b\u524d\u52a0\u4e0a\u5173\u952e\u5b57 explain \/ desc\n\nexplain select \u5b57\u6bb5\u5217\u8868 from \u8868\u540d where \u6761\u4ef6\uff1a<\/code><\/pre>\n\n\n\n
Explain \u6267\u884c\u8ba1\u5212\u4e2d\u5404\u4e2a\u5b57\u6bb5\u7684\u542b\u4e49<\/p>\n\n\n\n
\u5b57\u6bb5<\/td>\u542b\u4e49<\/td><\/tr>
id<\/td>select\u67e5\u8be2\u7684\u5e8f\u5217\u53f7\uff0c\u8868\u793a\u67e5\u8be2\u4e2d\u6267\u884cselect\u5b50\u53e5\u6216\u8005\u662f\u64cd\u4f5c\u8868\u7684\u987a\u5e8f
(id\u76f8\u540c\uff0c\u6267\u884c\u987a\u5e8f\u4ece\u4e0a\u5230\u4e0b\uff1bid\u4e0d\u540c\uff0c\u503c\u8d8a\u5927\uff0c\u8d8a\u5148\u6267\u884c)<\/td><\/tr>
select_type<\/td>\u8868\u793a SELECT \u7684\u7c7b\u578b\uff0c\u5e38\u89c1\u7684\u53d6\u503c\u6709 SIMPLE\uff08\u7b80\u5355\u8868\uff0c\u5373\u4e0d\u4f7f\u7528\u8868\u8fde\u63a5 \u6216\u8005\u5b50\u67e5\u8be2\uff09\u3001PRIMARY\uff08\u4e3b\u67e5\u8be2\uff0c\u5373\u5916\u5c42\u7684\u67e5\u8be2\uff09\u3001
UNION\uff08UNION \u4e2d\u7684\u7b2c\u4e8c\u4e2a\u6216\u8005\u540e\u9762\u7684\u67e5\u8be2\u8bed\u53e5\uff09\u3001
SUBQUERY\uff08SELECT\/WHERE\u4e4b\u540e\u5305\u542b\u4e86\u5b50\u67e5\u8be2\uff09\u7b49<\/td><\/tr>
type<\/td>\u8868\u793a\u8fde\u63a5\u7c7b\u578b\uff0c\u6027\u80fd\u7531\u597d\u5230\u5dee\u7684\u8fde\u63a5\u7c7b\u578b\u4e3aNULL\u3001system\u3001const\u3001
eq_ref\u3001ref\u3001range\u3001 index\u3001all<\/td><\/tr>
possible_key<\/td>\u663e\u793a\u53ef\u80fd\u5e94\u7528\u5728\u8fd9\u5f20\u8868\u4e0a\u7684\u7d22\u5f15\uff0c\u4e00\u4e2a\u6216\u591a\u4e2a<\/td><\/tr>
key<\/td>\u5b9e\u9645\u4f7f\u7528\u7684\u7d22\u5f15\uff0c\u5982\u679c\u4e3aNULL\uff0c\u5219\u6ca1\u6709\u4f7f\u7528\u7d22\u5f15<\/td><\/tr>
key_len<\/td>\u8868\u793a\u7d22\u5f15\u4e2d\u4f7f\u7528\u7684\u5b57\u8282\u6570\uff0c \u8be5\u503c\u4e3a\u7d22\u5f15\u5b57\u6bb5\u6700\u5927\u53ef\u80fd\u957f\u5ea6\uff0c\u5e76\u975e\u5b9e\u9645\u4f7f\u7528\u957f \u5ea6\uff0c\u5728\u4e0d\u635f\u5931\u7cbe\u786e\u6027\u7684\u524d\u63d0\u4e0b\uff0c \u957f\u5ea6\u8d8a\u77ed\u8d8a\u597d<\/td><\/tr>
rows<\/td>MySQL\u8ba4\u4e3a\u5fc5\u987b\u8981\u6267\u884c\u67e5\u8be2\u7684\u884c\u6570\uff0c\u5728innodb\u5f15\u64ce\u7684\u8868\u4e2d\uff0c\u662f\u4e00\u4e2a\u4f30\u8ba1\u503c\uff0c \u53ef\u80fd\u5e76\u4e0d\u603b\u662f\u51c6\u786e\u7684<\/td><\/tr>
filtered<\/td>\u8868\u793a\u8fd4\u56de\u7ed3\u679c\u7684\u884c\u6570\u5360\u9700\u8bfb\u53d6\u884c\u6570\u7684\u767e\u5206\u6bd4\uff0c filtered \u7684\u503c\u8d8a\u5927\u8d8a\u597d<\/td><\/tr>
extra<\/td>\u989d\u5916\u7684\u5185\u5bb9<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u89c6\u56fe<\/strong><\/h2>\n\n\n\n
\u542b\u4e49<\/strong><\/h3>\n\n\n\n
\u89c6\u56fe\uff08View\uff09\u662f\u4e00\u79cd\u865a\u62df\u5b58\u5728\u7684\u8868\u3002\u89c6\u56fe\u4e2d\u7684\u6570\u636e\u5e76\u4e0d\u5728\u6570\u636e\u5e93\u4e2d\u5b9e\u9645\u5b58\u5728\uff0c\u884c\u548c\u5217\u6570\u636e\u6765\u81ea\u5b9a\u4e49\u89c6 \u56fe\u7684\u67e5\u8be2\u4e2d\u4f7f\u7528\u7684\u8868\uff0c\u5e76\u4e14\u662f\u5728\u4f7f\u7528\u89c6\u56fe\u65f6\u52a8\u6001\u751f\u6210\u7684\u3002\u901a\u4fd7\u7684\u8bb2\uff0c\u89c6\u56fe\u53ea\u4fdd\u5b58\u4e86\u67e5\u8be2\u7684SQL\u903b\u8f91\uff0c\u4e0d\u4fdd\u5b58\u67e5\u8be2\u7ed3\u679c\u3002\u6240\u4ee5\u6211\u4eec\u5728\u521b\u5efa\u89c6\u56fe\u7684\u65f6\u5019\uff0c\u4e3b\u8981\u7684\u5de5\u4f5c \u5c31\u843d\u5728\u521b\u5efa\u8fd9\u6761SQL\u67e5\u8be2\u8bed\u53e5\u4e0a<\/p>\n\n\n\n
\u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
\u521b\u5efa<\/strong><\/p>\n\n\n\n
create or replace view  \u89c6\u56fe\u540d\u79f0(\u5217\u540d\u5217\u8868) as  select\u8bed\u6cd5   (with cascaded \/ local check option) <\/code><\/pre>\n\n\n\n
\u67e5\u8be2<\/strong><\/p>\n\n\n\n
\u67e5\u770b\u521b\u5efa\u89c6\u56fe\u8bed\u53e5\uff1a show create view \u89c6\u56fe\u540d\u79f0\n\u67e5\u770b\u89c6\u56fe\u6570\u636e\uff1a     select  * from \u89c6\u56fe\u540d\u79f0<\/code><\/pre>\n\n\n\n
\u4fee\u6539<\/strong><\/p>\n\n\n\n
\u7b2c\u4e00\u79cd\uff1a create or replace view \u89c6\u56fe\u540d\u79f0(\u5217\u540d\u5217\u8868) as select\u8bed\u6cd5 (with cascaded  \/ local check option)\n\u7b2c\u4e8c\u79cd\uff1a alter  view \u89c6\u56fe\u540d\u79f0  as select\u8bed\u6cd5(with cascaded \/ local check option)<\/code><\/pre>\n\n\n\n
\u5220\u9664<\/strong><\/p>\n\n\n\n
drop view  (if exists) (\u89c6\u56fe\u540d\u79f0)<\/code><\/pre>\n\n\n\n
\u89c6\u56fe\u5185\u7684dml\u8bed\u53e5<\/strong><\/h3>\n\n\n\n
\u4e0a\u9762\u6f14\u793a\u4e86\u89c6\u56fe\u7684\u521b\u5efa\uff0c\u4fee\u6539\uff0c\u5220\u9664\uff0c\u5176\u5b9e\u5728\u89c6\u56fe\u5185\u4e5f\u53ef\u4ee5\u8fdb\u884c\u6570\u636e\u7684\u589e\u5220\u6539\uff0c\u4f46\u662f\u8fd9\u4e9b\u589e\u5220\u6539\uff0c\u5b9e\u9645\u4e0a\u662f\u4f5c\u7528\u5230\u89c6\u56fe\u521b\u5efa\u6240\u4f7f\u7528\u7684\u8868\u4e0a\u7684\uff0c\u6bd4\u5982\u6211\u4eec\u662f\u6839\u636eaccount\u8868\u521b\u5efa\u7684\u89c6\u56fe\uff0c\u90a3\u4e48\u589e\u5220\u6539\u6700\u7ec8\u662f\u4f5c\u7528\u4e8eaccount\u8868\u4e0a\u7684<\/p>\n\n\n\n
\u5b9e\u4f8b\uff1a<\/p>\n\n\n\n
\u9009\u62e9\u6839\u636eaccount\u8868\u521b\u5efa\u7684aacount_a\u89c6\u56fe\uff0c<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5728\u89c6\u56fe\u5185\u589e\u52a0\u6570\u636e<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6700\u7ec8\u4f5c\u7528\u4e8eaccount\u8868\u5185\uff0caccount_a\u89c6\u56fe\u4e2d\u7406\u8bba\u4e0a\u4e5f\u4f1a\u6709\uff0c\u4f46\u662f\u524d\u63d0\u662f\u5728\u7ed9\u7684where\u6761\u4ef6\u5185<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4f46\u662f\u6b64\u65f6\uff0c\u4f7f\u7528\u67e5\u8be2\u8bed\u53e5select * from account_a\uff0c\u662f\u67e5\u4e0d\u5230 \u2018\u20196\uff0c\u674e\u742a\u742a\u2018\u2019\u7684\uff0c\u662f\u56e0\u4e3a\u6211\u5728\u521b\u5efa\u8be5\u89c6\u56fe\u7684\u65f6\u5019\u6307\u5b9a\u4e86id< 5,\u6307\u5b9a\u4e86\u89c4\u5219\uff0c\u6240\u4ee5\u67e5\u8be2\u4e0d\u5230\uff0c\u4f46\u662f\u5728\u57fa\u8868\u5185\u5e08\u5b58\u5728\u7684\uff0c\u800c\u5728\u89c6\u56fe\u5185\u4e0d\u5b58\u5728<\/p>\n\n\n\n
\u68c0\u67e5\u9009\u9879<\/strong><\/h3>\n\n\n\n
\u542b\u4e49<\/strong><\/p>\n\n\n\n
\u5f53\u4f7f\u7528with check option\u5b50\u53e5\u521b\u5efa\u89c6\u56fe\u65f6\uff0cMySQL\u4f1a\u901a\u8fc7\u89c6\u56fe\u68c0\u67e5\u6b63\u5728\u66f4\u6539\u7684\u6bcf\u4e2a\u884c\uff0c\u4f8b\u5982 \u63d2 \u5165\uff0c\u66f4\u65b0\uff0c\u5220\u9664\uff0c\u4ee5\u4f7f\u5176\u7b26\u5408\u89c6\u56fe\u7684\u5b9a\u4e49\u3002 MySQL\u5141\u8bb8\u57fa\u4e8e\u53e6\u4e00\u4e2a\u89c6\u56fe\u521b\u5efa\u89c6\u56fe\uff0c\u5b83\u8fd8\u4f1a\u68c0\u67e5\u4f9d\u8d56\u89c6 \u56fe\u4e2d\u7684\u89c4\u5219\u4ee5\u4fdd\u6301\u4e00\u81f4\u6027\u3002\u4e3a\u4e86\u786e\u5b9a\u68c0\u67e5\u7684\u8303\u56f4\uff0cmysql\u63d0\u4f9b\u4e86\u4e24\u4e2a\u9009\u9879\uff1acascaded\u548c local\uff0c\u9ed8\u8ba4\u503c\u4e3a cascaded<\/p>\n\n\n\n
\u8bed\u6cd5<\/strong><\/p>\n\n\n\n
create or replace view (\u89c6\u56fe\u540d) as select\u8bed\u53e5 with cascaded \/ local check option\n##with cascaded \/ local check option \u5fc5\u5e26\n<\/code><\/pre>\n\n\n\n
cascaded<\/strong><\/p>\n\n\n\n
\u7ea7\u8fde<\/p>\n\n\n\n
\u6bd4\u5982\uff0cv2\u89c6\u56fe\u662f\u57fa\u4e8ev1\u89c6\u56fe\u7684\uff0c\u5982\u679c\u5728v2\u89c6\u56fe\u521b\u5efa\u7684\u65f6\u5019\u6307\u5b9a\u4e86\u68c0\u67e5\u9009\u9879\u4e3a cascaded\uff0c\u4f46\u662fv1\u89c6\u56fe \u521b\u5efa\u65f6\u672a\u6307\u5b9a\u68c0\u67e5\u9009\u9879\u3002 \u5219\u5728\u6267\u884c\u68c0\u67e5\u65f6\uff0c\u4e0d\u4ec5\u4f1a\u68c0\u67e5v2\uff0c\u8fd8\u4f1a\u7ea7\u8054\u68c0\u67e5v2\u7684\u5173\u8054\u89c6\u56fev1<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6848\u4f8b\uff1a<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5728\u6b64\u6848\u4f8b\u4e2d,account_a2 \u6dfb\u52a0\u4e86cascaded\u68c0\u67e5\u8bed\u53e5,cascaded\u68c0\u67e5\u8bed\u53e5\u5177\u6709\u7ee7\u627f\u6027,\u5982\u672c\u6848\u4f8b\u5728account_a2\u4e2d\u6dfb\u52a0\u4e86\uff0c\u90a3\u4e48account_a1\u4e2d\u4e5f\u4f1a\u6709\u8be5\u68c0\u67e5\u8bed\u53e5<\/p>\n\n\n\n
\u6839\u636einsert into \u8bed\u53e5\u6267\u884c\u7ed3\u679c\u6765\u770b\uff1a<\/p>\n\n\n\n
(15,’\u674e\u53cc\u53cc’):\u8be5\u8bed\u53e5\u6267\u884c\u6210\u529f\uff0c\u56e0\u4e3a\u5728account_a2\u7d22\u5f15\u4e2d\uff0c\u5b8315\u5904\u4e8e\u4ea4\u96c6\u72b6\u600120<=15<=10,\u6267\u884c\u6210\u529f\uff0c\u4e14\u5728account_a2\u89c6\u56fe\u4e2d\u6709\u8be5\u6570\u636e<\/p>\n\n\n\n
(25,’\u4fc4\u73de\u72ee\u5a1c\u5a1c’):\u8be5\u8bed\u53e5\u6267\u884c\u5931\u8d25,\u5728account_a2\u4e2d\u6267\u884c\u6210\u529f\uff0c\u4f46\u662f\u5728\u57fa\u8868account\u4e2d\u5931\u8d25\uff0c\u56e0\u4e3acascaded\u7684\u7ee7\u627f\u6027,account_a1\u4e2d\u5177\u6709\u68c0\u67e5\u8bed\u53e5,25>20\u6700\u7ec8\u6267\u884c\u5931\u8d25<\/p>\n\n\n\n
(30,\u2018\u5f00\u5fc3\u59d0\u2019):\u8be5\u8bed\u53e5\u6267\u884c\u5931\u8d25\uff0c\u56e0\u4e3a\u5904\u4e8e\u4e09\u4e2a\u89c6\u56fe\u9650\u5ea6\u503c\u4e4b\u5916\uff0c\u4e0d\u591a\u505a\u89e3\u91ca<\/p>\n\n\n\n
(17,’\u5f20\u5175’):\u8be5\u8bed\u53e5\u6267\u884c\u6210\u529f\uff0c\u56e0\u4e3aa3\u6ca1\u6709\u4f7f\u7528\u68c0\u67e5\u8bed\u53e5\uff0c\u6240\u4ee5\u5f00\u59cb\u6210\u529f\u7684\uff0c\u9664\u4e86a1\uff0ca2\u9650\u503c\u4e4b\u7c7b\uff0c\u5728a1\uff0ca2\u89c6\u56fe\u5185\u5b58\u5728\uff0c\u4f46\u5e76\u4e0d\u5b58\u5728\u4e8ea3\u4e2d\uff0c\u56e0\u4e3a\u4e0d\u5728\u8be5\u9650\u503c\u4e4b\u7c7b<\/p>\n\n\n\n
(14,’\u738b\u7428’):\u8be5\u8bed\u53e5\u6267\u884c\u6210\u529f,\u5904\u4e8ea1,a2,a3\u9608\u503c\u4e4b\u7c7b\uff0c\u4f1a\u5b58\u5728\u4e8e\u4e09\u4e2a\u89c6\u56fe\u5185\uff0c\u5728a3\u4e2d\uff0c\u5904\u4e8e\u8be5\u9608\u503c\u5185\uff0c\u5b58\u5728\u4e8e\u8be5\u89c6\u56fe\u5185\uff0c\u5728a1\uff0ca2\u4e2d\uff0c\u7b26\u5408\u68c0\u67e5\u8bed\u53e5\uff0c\u5b58\u5728\u4e8ea1\uff0ca2\uff0c\u4e14\u4e0d\u4f1a\u62a5\u9519<\/p>\n\n\n\n
local<\/strong><\/p>\n\n\n\n
\u672c\u5730<\/p>\n\n\n\n
\u6bd4\u5982\uff0cv2\u89c6\u56fe\u662f\u57fa\u4e8ev1\u89c6\u56fe\u7684\uff0c\u5982\u679c\u5728v2\u89c6\u56fe\u521b\u5efa\u7684\u65f6\u5019\u6307\u5b9a\u4e86\u68c0\u67e5\u9009\u9879\u4e3a local \uff0c\u4f46\u662fv1\u89c6\u56fe\u521b \u5efa\u65f6\u672a\u6307\u5b9a\u68c0\u67e5\u9009\u9879\u3002 \u5219\u5728\u6267\u884c\u68c0\u67e5\u65f6\uff0c\u77e5\u4f1a\u68c0\u67e5v2\uff0c\u4e0d\u4f1a\u68c0\u67e5v2\u7684\u5173\u8054\u89c6\u56fev1<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5b9e\u4f8b\uff1a<\/p>\n\n\n\n
\u540c\u6837\u7684\u6570\u636e\uff0c\u66f4\u6539\u68c0\u67e5\u8bed\u53e5\u4e3a’with local check option’\uff0clocal \u68c0\u67e5\u4e0d\u4f1a\u7ee7\u627f\uff0c\u5373\u4e0d\u4f1a\u5411\u4e0a\u81f3a4<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u540c\u6837\u4ee5\u6dfb\u52a0\u6570\u636e\u8bed\u53e5\u6765\u770b\uff1a<\/p>\n\n\n\n
\u674e\u53cc\u53cc\uff1a \u6267\u884c\u6210\u529f\uff0c\u5904\u4e8ea4\uff0ca5\u4ea4\u96c6<\/p>\n\n\n\n
\u4fc4\u73de\u72ee\u5a1c\u5a1c\uff1a\u6267\u884c\u6210\u529f\uff0c\u56e0\u4e3a\u53ea\u6709a5\u6709\u68c0\u67e5\u8bed\u53e5\uff0c\u800c\u521a\u597d\u5904\u4e8e\u68c0\u67e5\u8bed\u53e5\u5185\uff0clocal\u4e0d\u4f1a\u5411\u4e0a\u7ee7\u627f\uff0c\u6240\u4ee5\u6b64\u5904\u6210\u529f\uff0c\u4f46\u662f\u53ea\u4f1a\u5728\u57fa\u8868\u6709\u6570\u636e<\/p>\n\n\n\n
\u5f00\u5fc3\u59d0\uff1a\u6267\u884c\u6210\u529f\uff0c\u4f46\u662f\u4e0d\u4f1a\u518da4\uff0ca5\uff0ca6\u4efb\u4f55\u4e00\u4e2a\u89c6\u56fe\u5185\uff0c\u800c\u4f1a\u5b58\u5728\u4e8e\u57fa\u8868\u4e2d\uff0c<\/p>\n\n\n\n
\u5f20\u5175\uff1a\u6267\u884c\u6210\u529f\uff0c\u4f46\u662f\u4e0d\u4f1a\u5b58\u5728\u4e8ea6\uff0c\u53ea\u4f1a\u5b58\u5728\u4e8ea4\uff0ca5<\/p>\n\n\n\n
\u738b\u7428\uff1a\u6267\u884c\u6210\u529f\uff0c\u4f1a\u5b58\u5728\u4e8ea6\uff0ca5\uff0ca4<\/p>\n\n\n\n
cascaded\u4e0elocal\u7684\u533a\u522b\uff1a<\/strong><\/p>\n\n\n\n
cascaded\u4f1a\u5411\u4e0a\u7ee7\u627f\u5176\u68c0\u67e5\u8bed\u53e5\uff0c\u800clocal\u4e0d\u4f1a\u5411\u4e0a\u7ee7\u627f\u5176\u68c0\u67e5\u8bed\u53e5\uff0c\u4f46\u5e76\u4e0d\u610f\u5473\u7740\u4e0d\u7ba1\u4e0a\u9762\u8bed\u53e5\u7684\u9650\u503c\uff0c\u5982where<20,\u53ea\u662f\u4e0d\u4f1a\u6dfb\u52a0\u68c0\u67e5\u8bed\u53e5\uff0c\u5f53\u4e0d\u6ee1\u8db3\u5176\u6761\u4ef6\u5c5e\u6027\uff0c\u4e0d\u4f1a\u62a5\u9519\u800c\u5df2<\/p>\n\n\n\n
\u89c6\u56fe\u7684\u66f4\u65b0<\/strong><\/h3>\n\n\n\n
\u8981\u4f7f\u89c6\u56fe\u53ef\u66f4\u65b0\uff0c\u89c6\u56fe\u4e2d\u7684\u884c\u4e0e\u57fa\u7840\u8868\u4e2d\u7684\u884c\u4e4b\u95f4\u5fc5\u987b\u5b58\u5728\u4e00\u5bf9\u4e00\u7684\u5173\u7cfb\u3002\u5982\u679c\u89c6\u56fe\u5305\u542b\u4ee5\u4e0b\u4efb\u4f55\u4e00 \u9879\uff0c\u5219\u8be5\u89c6\u56fe\u4e0d\u53ef\u66f4\u65b0\uff1a<\/p>\n\n\n\n
A. \u805a\u5408\u51fd\u6570\u6216\u7a97\u53e3\u51fd\u6570\uff08SUM()\u3001 MIN()\u3001 MAX()\u3001 COUNT()\u7b49\uff09<\/p>\n\n\n\n
B. DISTINCT<\/p>\n\n\n\n
 C. GROUP BY <\/p>\n\n\n\n
D. HAVING <\/p>\n\n\n\n
E. UNION \u6216\u8005 UNION ALL<\/p>\n\n\n\n
\u53ea\u6709\u4e00\u4e2a\u5355\u884c\u5355\u5217\u7684\u6570\u636e\uff0c\u5982\u679c\u6211\u4eec\u5bf9\u8fd9\u4e2a\u89c6\u56fe\u8fdb\u884c\u66f4\u65b0\u6216\u63d2\u5165\u7684\uff0c\u5c06\u4f1a\u62a5\u9519<\/p>\n\n\n\n
\u89c6\u56fe\u4f5c\u7528<\/strong><\/h3>\n\n\n\n
1.\u7b80\u5355<\/strong>\uff1a \u89c6\u56fe\u4e0d\u4ec5\u53ef\u4ee5\u7b80\u5316\u7528\u6237\u5bf9\u6570\u636e\u7684\u7406\u89e3\uff0c\u4e5f\u53ef\u4ee5\u7b80\u5316\u4ed6\u4eec\u7684\u64cd\u4f5c\u3002\u90a3\u4e9b\u88ab\u7ecf\u5e38\u4f7f\u7528\u7684\u67e5\u8be2\u53ef\u4ee5\u88ab\u5b9a\u4e49\u4e3a\u89c6 \u56fe\uff0c\u4ece\u800c\u4f7f\u5f97\u7528\u6237\u4e0d\u5fc5\u4e3a\u4ee5\u540e\u7684\u64cd\u4f5c\u6bcf\u6b21\u6307\u5b9a\u5168\u90e8\u7684\u6761\u4ef6\u3002<\/p>\n\n\n\n
2. \u5b89\u5168<\/strong> \uff1a\u6570\u636e\u5e93\u53ef\u4ee5\u6388\u6743\uff0c\u4f46\u4e0d\u80fd\u6388\u6743\u5230\u6570\u636e\u5e93\u7279\u5b9a\u884c\u548c\u7279\u5b9a\u7684\u5217\u4e0a\u3002\u901a\u8fc7\u89c6\u56fe\u7528\u6237\u53ea\u80fd\u67e5\u8be2\u548c\u4fee\u6539\u4ed6\u4eec\u6240\u80fd\u89c1\u5230\u7684\u6570\u636e<\/p>\n\n\n\n
3.\u6570\u636e\u72ec\u7acb<\/strong>\uff1a \u89c6\u56fe\u53ef\u5e2e\u52a9\u7528\u6237\u5c4f\u853d\u771f\u5b9e\u8868\u7ed3\u6784\u53d8\u5316\u5e26\u6765\u7684\u5f71\u54cd\u3002<\/p>\n\n\n\n
\u5b58\u50a8\u8fc7\u7a0b<\/strong><\/h2>\n\n\n\n
\u6982\u8ff0<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/p>\n\n\n\n
\u5b58\u50a8\u8fc7\u7a0b\u662f\u4e8b\u5148\u7ecf\u8fc7\u7f16\u8bd1\u5e76\u5b58\u50a8\u5728\u6570\u636e\u5e93\u4e2d\u7684\u4e00\u6bb5SQL \u8bed\u53e5\u7684\u96c6\u5408\uff0c\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b\u53ef\u4ee5\u7b80\u5316\u5e94\u7528\u5f00\u53d1\u4eba\u5458\u7684\u5f88\u591a\u5de5\u4f5c\uff0c\u51cf\u5c11\u6570\u636e\u5728\u6570\u636e\u5e93\u548c\u5e94\u7528\u670d\u52a1\u5668\u4e4b\u95f4\u7684\u4f20\u8f93\uff0c\u5bf9\u4e8e\u63d0\u9ad8\u6570\u636e\u5904\u7406\u7684\u6548\u7387\u662f\u6709\u597d\u5904\u7684\u3002\u5b58\u50a8\u8fc7\u7a0b\u601d\u60f3\u4e0a\u5f88\u7b80\u5355\uff0c\u5c31\u662f\u6570\u636e\u5e93SQL \u8bed\u8a00\u5c42\u9762\u7684\u4ee3\u7801\u5c01\u88c5\u4e0e\u91cd\u7528\u3002<\/p>\n\n\n\n
\u7279\u70b9<\/strong><\/p>\n\n\n\n
\u5c01\u88c5\uff0c\u590d\u7528<\/strong>  ———————–> \u53ef\u4ee5\u628a\u67d0\u4e00\u4e1a\u52a1SQL\u5c01\u88c5\u5728\u5b58\u50a8\u8fc7\u7a0b\u4e2d\uff0c\u9700\u8981\u7528\u5230\u7684\u65f6\u5019\u76f4\u63a5\u8c03\u7528\u5373\u53ef<\/p>\n\n\n\n
\u53ef\u4ee5\u63a5\u6536\u53c2\u6570\uff0c\u4e5f\u53ef\u4ee5\u8fd4\u56de\u6570\u636e<\/strong> ——–> \u518d\u5b58\u50a8\u8fc7\u7a0b\u4e2d\uff0c\u53ef\u4ee5\u4f20\u9012\u53c2\u6570\uff0c\u4e5f\u53ef\u4ee5\u63a5\u6536\u8fd4\u56de\u503c<\/p>\n\n\n\n
\u51cf\u5c11\u7f51\u7edc\u4ea4\u4e92\uff0c\u6548\u7387\u63d0\u5347<\/strong> ————-> \u5982\u679c\u6d89\u53ca\u5230\u591a\u6761SQL\uff0c\u6bcf\u6267\u884c\u4e00\u6b21\u90fd\u662f\u4e00\u6b21\u7f51\u7edc\u4f20\u8f93\u3002\u800c\u5982\u679c\u5c01\u88c5\u5728\u5b58\u50a8\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u53ea\u9700\u8981\u7f51\u7edc\u4ea4\u4e92\u4e00\u6b21\u53ef\u80fd\u5c31\u53ef\u4ee5\u4e86<\/p>\n\n\n\n
\u57fa\u672c\u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
\u4fee\u6539\u7ed3\u675f\u7b26\u53f7<\/strong><\/p>\n\n\n\n
delimiter +\u7b26\u53f7<\/code><\/pre>\n\n\n\n
\u5982\uff1a \u7ed3\u675f\u7b26\u4fee\u6539\u4e3a’$$’  \u540e\u65e0\u6cd5\u518d\u6b21\u901a\u8fc7  \u2018;\u2019\u6267\u884c\u547d\u4ee4<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u521b\u5efa<\/strong><\/p>\n\n\n\n
create procedure   \u5b58\u50a8\u8fc7\u7a0b\u540d\u79f0(\u53c2\u6570\u5217\u8868)\nbegin\n      --sql\u8bed\u53e5;\nend;\n##\u5728\u7c7b\u4f3cdatagrip\u7684\u53ef\u89c6\u5316\u56fe\u5f62\u754c\u9762\u5e94\u7528\u4e0a\uff0c\u547d\u4ee4\u884c\u9700\u8981\u4fee\u6539\u7ed3\u675f\u7b26<\/code><\/pre>\n\n\n\n
\u4f8b\u5982\uff1a\u521b\u5efap1\u5b58\u50a8\u8fc7\u7a0b<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u8c03\u7528<\/strong><\/p>\n\n\n\n
call  \u5b58\u50a8\u8fc7\u7a0b\u540d\u79f0(\u53c2\u6570);<\/code><\/pre>\n\n\n\n
\u67e5\u770b<\/strong><\/p>\n\n\n\n
select * from    INFORMATION_`SCHEMA.ROUTINES   where    ROUTINE_SCHEMA='xxx'; ##\u67e5\u8be2\u6307\u5b9a\u6570\u636e\u5e93\u7684\u5b58\u50a8\u8fc7\u7a0b\u53ca\u72b6\u6001\u4fe1\u606f\n\nshow create procedure \u5b58\u50a8\u8fc7\u7a0b\u540d\u79f0     ##\u67e5\u8be2\u67d0\u4e2a\u5b58\u50a8\u8fc7\u7a0b\u7684\u5b9a\u4e49\n<\/code><\/pre>\n\n\n\n
\u5220\u9664<\/strong><\/p>\n\n\n\n
drop procedure if exists + \u5b58\u50a8\u8fc7\u7a0b\u540d\u79f0   <\/code><\/pre>\n\n\n\n
\u5728\u547d\u4ee4\u884c\u4e2d\uff0c\u6267\u884c\u521b\u5efa\u5b58\u50a8\u8fc7\u7a0b\u7684SQL\u65f6\uff0c\u9700\u8981\u901a\u8fc7\u5173\u952e\u5b57delimiter \u6307\u5b9aSQL\u8bed\u53e5\u7684\u7ed3\u675f\u7b26\u3002<\/strong><\/p>\n\n\n\n
\u53d8\u91cf<\/strong><\/h3>\n\n\n\n
\u5728MySQL\u4e2d\u53d8\u91cf\u5206\u4e3a\u4e09\u79cd\u7c7b\u578b: \u7cfb\u7edf\u53d8\u91cf\u3001\u7528\u6237\u5b9a\u4e49\u53d8\u91cf\u3001\u5c40\u90e8\u53d8\u91cf\u3002<\/p>\n\n\n\n
\u7cfb\u7edf\u53d8\u91cf<\/strong><\/h4>\n\n\n\n
\u7cfb\u7edf\u53d8\u91cf\u662fMySQL\u670d\u52a1\u5668\u63d0\u4f9b\uff0c\u4e0d\u662f\u7528\u6237\u5b9a\u4e49\u7684\uff0c\u5c5e\u4e8e\u670d\u52a1\u5668\u5c42\u9762\u3002\u5206\u4e3a\u5168\u5c40\u53d8\u91cf\uff08GLOBAL\uff09\u3001\u4f1a\u8bdd<\/p>\n\n\n\n
\u53d8\u91cf\uff08SESSION\uff09<\/p>\n\n\n\n
\u67e5\u770b\u7cfb\u7edf\u53d8\u91cf<\/strong><\/p>\n\n\n\n
show global| session variables;\nshow global| session variables  like ''    ##\u6a21\u7cca\u67e5\u8be2\u6cd5\n\nselect @@(session|global). \u7cfb\u7edf\u53d8\u91cf\u540d <\/code><\/pre>\n\n\n\n
\u6ce8\u610f<\/strong><\/p>\n\n\n\n
\u5982\u679c\u6ca1\u6709\u6307\u5b9aSESSION\/GLOBAL\uff0c\u9ed8\u8ba4\u662fSESSION\uff0c\u4f1a\u8bdd\u53d8\u91cf<\/p>\n\n\n\n
mysql\u670d\u52a1\u91cd\u65b0\u542f\u52a8\u4e4b\u540e\uff0c\u6240\u8bbe\u7f6e\u7684\u5168\u5c40\u53c2\u6570\u4f1a\u5931\u6548\uff0c\u8981\u60f3\u4e0d\u5931\u6548\uff0c\u53ef\u4ee5\u5728\/etc\/my.cnf\u4e2d\u914d\u7f6e<\/p>\n\n\n\n
A. \u5168\u5c40\u53d8\u91cf(GLOBAL): \u5168\u5c40\u53d8\u91cf\u9488\u5bf9\u4e8e\u6240\u6709\u7684\u4f1a\u8bdd<\/p>\n\n\n\n
B. \u4f1a\u8bdd\u53d8\u91cf(SESSION): \u4f1a\u8bdd\u53d8\u91cf\u9488\u5bf9\u4e8e\u5355\u4e2a\u4f1a\u8bdd\uff0c\u5728\u53e6\u5916\u4e00\u4e2a\u4f1a\u8bdd\u7a97\u53e3\u5c31\u4e0d\u751f\u6548\u4e86<\/p>\n\n\n\n
\u8bbe\u7f6e\u7cfb\u7edf\u53d8\u91cf<\/strong><\/p>\n\n\n\n
set global|session \u7cfb\u7edf\u53d8\u91cf\u540d = \u503c \uff1b\nselect @@(global|session) .\u7cfb\u7edf\u53d8\u91cf\u540d= \u503c\uff1b<\/code><\/pre>\n\n\n\n
\u7528\u6237\u81ea\u5b9a\u4e49\u53d8\u91cf<\/strong><\/h4>\n\n\n\n
\u7c7b\u4f3c\u5168\u5c40<\/strong><\/h5>\n\n\n\n
\u7528\u6237\u5b9a\u4e49\u53d8\u91cf\u662f\u7528\u6237\u6839\u636e\u9700\u8981\u81ea\u5df1\u5b9a\u4e49\u7684\u53d8\u91cf\uff0c\u7528\u6237\u53d8\u91cf\u4e0d\u7528\u63d0\u524d\u58f0\u660e\uff0c\u5728\u7528\u7684\u65f6\u5019\u76f4\u63a5\u7528”@\u53d8\u91cf\u540d” \u4f7f\u7528\u5c31\u53ef\u4ee5\u3002\u5176\u4f5c\u7528\u57df\u4e3a\u5f53\u524d\u8fde\u63a5<\/p>\n\n\n\n
\u8d4b\u503c<\/strong><\/p>\n\n\n\n
set @\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d = \u503c  , @\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d = \u503c;\nset @\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d  := \u503c,@\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d = \u503c;\n##\u5bf9\u4e8eset  \u53ef\u4ee5\u4f7f\u7528 =  \u4e5f\u53ef\u4ee5\u4f7f\u7528:=\n\nselect @\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d  := \u503c,@\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d = \u503c;\nselect  \u5b57\u6bb5\u540d into @\u81ea\u5b9a\u4e49\u53d8\u91cf\u540d  from \u8868\u540d;<\/code><\/pre>\n\n\n\n
\u4f7f\u7528<\/strong><\/p>\n\n\n\n
select @\u81ea\u5b9a\u4e49\u7528\u53d8\u91cf;<\/code><\/pre>\n\n\n\n
\u7528\u6237\u5b9a\u4e49\u7684\u53d8\u91cf\u65e0\u9700\u5bf9\u5176\u8fdb\u884c\u58f0\u660e\u6216\u521d\u59cb\u5316\uff0c\u53ea\u4e0d\u8fc7\u83b7\u53d6\u5230\u7684\u503c\u4e3aNULL\u3002\u610f\u601d\u4e3a\u81ea\u5b9a\u4e49\u7528\u6237\u53d8\u91cf\u82e5\u6ca1\u6709\u7ed9\u5b9a\u503c\uff0c\u8fd4\u56denull\u800c\u4e0d\u62a5\u9519<\/p>\n\n\n\n
\u7c7b\u4f3c\u5c40\u90e8\u53d8\u91cf<\/strong><\/h5>\n\n\n\n
\u5c40\u90e8\u53d8\u91cf\u662f\u6839\u636e\u9700\u8981\u5b9a\u4e49\u7684\u5728\u5c40\u90e8\u751f\u6548\u7684\u53d8\u91cf\uff0c\u8bbf\u95ee\u4e4b\u524d\uff0c\u9700\u8981DECLARE\u58f0\u660e\u3002\u53ef\u7528\u4f5c\u5b58\u50a8\u8fc7\u7a0b\u5185\u7684\u5c40\u90e8\u53d8\u91cf\u548c\u8f93\u5165\u53c2\u6570\uff0c\u5c40\u90e8\u53d8\u91cf\u7684\u8303\u56f4\u662f\u5728\u5176\u5185\u58f0\u660e\u7684BEGIN … END\u5757<\/p>\n\n\n\n
\u58f0\u660e<\/strong><\/p>\n\n\n\n
declare  \u53d8\u91cf\u540d  \u53d8\u91cf\u7c7b\u578b  (default 0);\n\u53d8\u91cf\u7c7b\u578b\u5c31\u662f\u6570\u636e\u5e93\u5b57\u6bb5\u7c7b\u578b\uff1aINT\u3001BIGINT\u3001CHAR\u3001VARCHAR,DATE\u3001TIME\u7b49<\/code><\/pre>\n\n\n\n
\u8d4b\u503c<\/strong><\/p>\n\n\n\n
set \u53d8\u91cf\u540d = \u503c\nset  \u53d8\u91cf\u540d := \u503c\nselect \u5b57\u6bb5\u540d into \u81ea\u5b9a\u4e49\u53d8\u91cf\u540d  from \u8868\u540d;<\/code><\/pre>\n\n\n\n
\u4f8b\u5982\uff1a1.–\u58f0\u660e\u5c40\u90e8\u53d8\u91cf-declare  2.–\u8d4b\u503c 3 — \u4f7f\u7528\u53d8\u91cf\u540d 4–\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
if<\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/p>\n\n\n\n
if \u7528\u4e8e\u505a\u6761\u4ef6\u5224\u65ad\uff0c\u5177\u4f53\u7684\u8bed\u6cd5\u7ed3\u6784\u4e3a<\/p>\n\n\n\n
if \u6761\u4ef61 then\n.....\nelseif \u6761\u4ef62 then -- \u53ef\u9009\n.....\nelse -- \u53ef\u9009\n.....\nend if;<\/code><\/pre>\n\n\n\n
\u5728if\u6761\u4ef6\u5224\u65ad\u7684\u7ed3\u6784\u4e2d\uff0cELSE IF \u7ed3\u6784\u53ef\u4ee5\u6709\u591a\u4e2a\uff0c\u4e5f\u53ef\u4ee5\u6ca1\u6709\u3002 ELSE\u7ed3\u6784\u53ef\u4ee5\u6709\uff0c\u4e5f\u53ef\u4ee5\u6ca1\u6709<\/p>\n\n\n\n
\u6848\u4f8b<\/strong><\/p>\n\n\n\n
\u6839\u636e\u5b9a\u4e49\u7684\u5206\u6570score\u53d8\u91cf\uff0c\u5224\u5b9a\u5f53\u524d\u5206\u6570\u5bf9\u5e94\u7684\u5206\u6570\u7b49\u7ea7<\/p>\n\n\n\n
score >= 85\u5206\uff0c\u7b49\u7ea7\u4e3a\u4f18\u79c0<\/p>\n\n\n\n
score >= 60\u5206 \u4e14 score < 85\u5206\uff0c\u7b49\u7ea7\u4e3a\u53ca\u683c<\/p>\n\n\n\n
score < 60\u5206\uff0c\u7b49\u7ea7\u4e3a\u4e0d\u53ca\u683c<\/p>\n\n\n\n
create procedure p3()\nbegin\n    declare score int default 58;\n    declare result varchar(10);\n\n    if score >= 85 then\n        set result := '\u4f18\u79c0';\n\n    elseif score >= 60 then\n        set result := '\u53ca\u683c';\n\n    else\n        set result := '\u4e0d\u53ca\u683c';\n    end if;\n    select result;\nend;\n\n\ncall p3();    \u8c03\u7528\n <\/code><\/pre>\n\n\n\n
\u4e0a\u8ff0\u7684\u9700\u6c42\u6211\u4eec\u867d\u7136\u5df2\u7ecf\u5b9e\u73b0\u4e86\uff0c\u4f46\u662f\u4e5f\u5b58\u5728\u4e00\u4e9b\u95ee\u9898\uff0c\u6bd4\u5982\uff1ascore \u5206\u6570\u6211\u4eec\u662f\u5728\u5b58\u50a8\u8fc7\u7a0b\u4e2d\u5b9a\u4e49<\/p>\n\n\n\n
\u6b7b\u7684\uff0c\u800c\u4e14\u6700\u7ec8\u8ba1\u7b97\u51fa\u6765\u7684\u5206\u6570\u7b49\u7ea7\uff0c\u6211\u4eec\u4e5f\u4ec5\u4ec5\u662f\u6700\u7ec8\u67e5\u8be2\u5c55\u793a\u51fa\u6765\u800c\u5df2\u3002\u800c\u628ascore\u5206\u6570\u52a8\u6001\u7684\u4f20\u9012\u8fdb\u6765\uff0c\u9700\u8981\u4f7f\u7528\u53c2\u6570<\/p>\n\n\n\n
\u53c2\u6570<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/p>\n\n\n\n
\u53c2\u6570\u7684\u7c7b\u578b\uff0c\u4e3b\u8981\u5206\u4e3a\u4ee5\u4e0b\u4e09\u79cd\uff1aIN\u3001OUT\u3001INOUT\u3002 \u5177\u4f53\u7684\u542b\u4e49\u5982\u4e0b\uff1a<\/p>\n\n\n\n
\u7c7b\u578b<\/td>\u542b\u4e49<\/td>\u5907\u6ce8<\/td><\/tr>
in<\/td>\u8be5\u7c7b\u53c2\u6570\u4f5c\u4e3a\u8f93\u5165\uff0c\u4e5f\u5c31\u662f\u9700\u8981\u8c03\u7528\u65f6\u4f20\u5165\u503c<\/td>\u9ed8\u8ba4<\/td><\/tr>
out<\/td>\u8be5\u7c7b\u53c2\u6570\u4f5c\u4e3a\u8f93\u51fa\uff0c\u4e5f\u5c31\u662f\u8be5\u53c2\u6570\u53ef\u4ee5\u4f5c\u4e3a\u8fd4\u56de\u503c<\/td><\/td><\/tr>
inout<\/td>\u65e2\u53ef\u4ee5\u4f5c\u4e3a\u8f93\u5165\u53c2\u6570\uff0c\u4e5f\u53ef\u4ee5\u4f5c\u4e3a\u8f93\u51fa\u53c2\u6570<\/td><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u7528\u6cd5<\/strong><\/p>\n\n\n\n
CREATE PROCEDURE \u5b58\u50a8\u8fc7\u7a0b\u540d\u79f0 ([ IN\/OUT\/INOUT \u53c2\u6570\u540d \u53c2\u6570\u7c7b\u578b ])\nBEGIN\n-- SQL\u8bed\u53e5\nEND ;<\/code><\/pre>\n\n\n\n
\u6848\u4f8b<\/strong><\/p>\n\n\n\n
\u6839\u636e\u4f20\u5165\u53c2\u6570score\uff0c\u5224\u5b9a\u5f53\u524d\u5206\u6570\u5bf9\u5e94\u7684\u5206\u6570\u7b49\u7ea7\uff0c\u5e76\u8fd4\u56de\u3002<\/p>\n\n\n\n
score >= 85\u5206\uff0c\u7b49\u7ea7\u4e3a\u4f18\u79c0\u3002<\/p>\n\n\n\n
score >= 60\u5206 \u4e14 score < 85\u5206\uff0c\u7b49\u7ea7\u4e3a\u53ca\u683c\u3002<\/p>\n\n\n\n
score < 60\u5206\uff0c\u7b49\u7ea7\u4e3a\u4e0d\u53ca\u683c<\/p>\n\n\n\n
create procedure p4(in score int, out result varchar(10))\nbegin\n    if score >= 85 then\n        set result := '\u4f18\u79c0';\n\n    elseif score >= 60 then\n        set result := '\u53ca\u683c';\n    else\n        set result := '\u4e0d\u53ca\u683c';\n    end if;\n\nend;\n\n\n-- \u5b9a\u4e49\u7528\u6237\u53d8\u91cf @result\u6765\u63a5\u6536\u8fd4\u56de\u7684\u6570\u636e, \u7528\u6237\u53d8\u91cf\u53ef\u4ee5\u4e0d\u7528\u58f0\u660e\ncall p4(18, @result);\n\nselect @result;\n<\/code><\/pre>\n\n\n\n
case<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/p>\n\n\n\n
case\u7ed3\u6784\u53ca\u4f5c\u7528\uff0c\u548c\u6211\u4eec\u5728\u57fa\u7840\u7bc7\u4e2d\u6240\u8bb2\u89e3\u7684\u6d41\u7a0b\u63a7\u5236\u51fd\u6570\u5f88\u7c7b\u4f3c\u3002\u6709\u4e24\u79cd\u8bed\u6cd5\u683c\u5f0f\uff1a<\/p>\n\n\n\n
\u8bed\u6cd5\u4e00\uff1a<\/p>\n\n\n\n
-- \u542b\u4e49\uff1a \u5f53case_value\u7684\u503c\u4e3a when_value1\u65f6\uff0c\u6267\u884cstatement_list1\uff0c\u5f53\u503c\u4e3a when_value2\u65f6\uff0c\n\u6267\u884cstatement_list2\uff0c \u5426\u5219\u5c31\u6267\u884c statement_list\n\nCASE case_value\n    WHEN when_value1 THEN statement_list1\n    [ WHEN when_value2 THEN statement_list2] ...\n    [ ELSE statement_list ]\nEND CASE;\n<\/code><\/pre>\n\n\n\n
\u8bed\u6cd5\u4e8c<\/p>\n\n\n\n
-- \u542b\u4e49\uff1a \u5f53\u6761\u4ef6search_condition1\u6210\u7acb\u65f6\uff0c\u6267\u884cstatement_list1\uff0c\u5f53\u6761\u4ef6search_condition2\u6210\n\u7acb\u65f6\uff0c\u6267\u884cstatement_list2\uff0c \u5426\u5219\u5c31\u6267\u884c statement_list\nCASE\n    WHEN search_condition1 THEN statement_list1\n    [WHEN search_condition2 THEN statement_list2] ...\n    [ELSE statement_list]\nEND CASE;<\/code><\/pre>\n\n\n\n
\u6848\u4f8b<\/p>\n\n\n\n
\u6839\u636e\u4f20\u5165\u7684\u6708\u4efd\uff0c\u5224\u5b9a\u6708\u4efd\u6240\u5c5e\u7684\u5b63\u8282\uff08\u8981\u6c42\u91c7\u7528case\u7ed3\u6784\uff09\u3002<\/p>\n\n\n\n
1-3\u6708\u4efd\uff0c\u4e3a\u7b2c\u4e00\u5b63\u5ea6<\/p>\n\n\n\n
4-6\u6708\u4efd\uff0c\u4e3a\u7b2c\u4e8c\u5b63\u5ea6<\/p>\n\n\n\n
7-9\u6708\u4efd\uff0c\u4e3a\u7b2c\u4e09\u5b63\u5ea6<\/p>\n\n\n\n
10-12\u6708\u4efd\uff0c\u4e3a\u7b2c\u56db\u5b63\u5ea6<\/p>\n\n\n\n
create procedure p6(in month int)\nbegin\n    declare result varchar(10);\n\n    case\n        when month >=1 and month <=3 then\n            set result := '\u7b2c\u4e00\u5b63\u5ea6';\n        when month >=4 and month <=6 then\n            set result := '\u7b2c\u4e8c\u5b63\u5ea6';\n        when month >=7 and month <=9 then\n            set result := '\u7b2c\u4e09\u5b63\u5ea6';\n        when month >=10 and month <=12 then\n            set result := '\u7b2c\u56db\u5b63\u5ea6';\n        else\n            set result :='\u975e\u6cd5\u53c2\u6570';\n    end case;\n\n    select concat('\u4f60\u8f93\u5165\u7684\u6708\u4efd\u4e3a:',month,'\u6240\u5c5e\u7684\u5b63\u5ea6\u4e3a:',result);\nend;\n\ncall p6(13);\n<\/code><\/pre>\n\n\n\n
while<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
while \u5faa\u73af\u662f\u6709\u6761\u4ef6\u7684\u5faa\u73af\u63a7\u5236\u8bed\u53e5\u3002\u6ee1\u8db3\u6761\u4ef6\u540e\uff0c\u518d\u6267\u884c\u5faa\u73af\u4f53\u4e2d\u7684SQL\u8bed\u53e5\u3002\u5177\u4f53\u8bed\u6cd5\u4e3a\uff1a<\/p>\n\n\n\n
-- \u5148\u5224\u5b9a\u6761\u4ef6\uff0c\u5982\u679c\u6761\u4ef6\u4e3atrue\uff0c\u5219\u6267\u884c\u903b\u8f91\uff0c\u5426\u5219\uff0c\u4e0d\u6267\u884c\u903b\u8f91\nWHILE \u6761\u4ef6 DO\n    SQL\u903b\u8f91...\nEND WHILE;<\/code><\/pre>\n\n\n\n
\u6848\u4f8b<\/p>\n\n\n\n
\u8ba1\u7b97\u4ece1\u7d2f\u52a0\u5230n\u7684\u503c\uff0cn\u4e3a\u4f20\u5165\u7684\u53c2\u6570\u503c\u3002<\/p>\n\n\n\n
-- A. \u5b9a\u4e49\u5c40\u90e8\u53d8\u91cf, \u8bb0\u5f55\u7d2f\u52a0\u4e4b\u540e\u7684\u503c;\n-- B. \u6bcf\u5faa\u73af\u4e00\u6b21, \u5c31\u4f1a\u5bf9n\u8fdb\u884c\u51cf1 , \u5982\u679cn\u51cf\u52300, \u5219\u9000\u51fa\u5faa\u73af\ncreate procedure p7(in n int)\nbegin\n    declare total int default 0;\n    while n >0 do\n        set total := total +n;\n        set n := n-1;\n\n    end while;\n    select total;\nend;\n\ncall p7(180);\n<\/code><\/pre>\n\n\n\n
repeat<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
repeat\u662f\u6709\u6761\u4ef6\u7684\u5faa\u73af\u63a7\u5236\u8bed\u53e5, \u5f53\u6ee1\u8db3until\u58f0\u660e\u7684\u6761\u4ef6\u7684\u65f6\u5019\uff0c\u5219\u9000\u51fa\u5faa\u73af \u3002\u5177\u4f53\u8bed\u6cd5\u4e3a\uff1a<\/p>\n\n\n\n
-- \u5148\u6267\u884c\u4e00\u6b21\u903b\u8f91\uff0c\u7136\u540e\u5224\u5b9aUNTIL\u6761\u4ef6\u662f\u5426\u6ee1\u8db3\uff0c\u5982\u679c\u6ee1\u8db3\uff0c\u5219\u9000\u51fa\u3002\u5982\u679c\u4e0d\u6ee1\u8db3\uff0c\u5219\u7ee7\u7eed\u4e0b\u4e00\u6b21\u5faa\u73af\nREPEAT\n    SQL\u903b\u8f91...\n    UNTIL \u6761\u4ef6\nEND REPEAT;<\/code><\/pre>\n\n\n\n
\u6848\u4f8b<\/p>\n\n\n\n
\u8ba1\u7b97\u4ece1\u7d2f\u52a0\u5230n\u7684\u503c\uff0cn\u4e3a\u4f20\u5165\u7684\u53c2\u6570\u503c\u3002(\u4f7f\u7528repeat\u5b9e\u73b0)<\/p>\n\n\n\n
create procedure p8(in n int )\nbegin\n    declare total int default 0;\n\n    repeat\n        set total := total+n;\n        set n := n -1;\n    until n<=0\n\n    end repeat;\n    select total;\n\nend;\n\ncall p8(1080);<\/code><\/pre>\n\n\n\n
loop<\/strong><\/h3>\n\n\n\n
LOOP \u5b9e\u73b0\u7b80\u5355\u7684\u5faa\u73af\uff0c\u5982\u679c\u4e0d\u5728SQL\u903b\u8f91\u4e2d\u589e\u52a0\u9000\u51fa\u5faa\u73af\u7684\u6761\u4ef6\uff0c\u53ef\u4ee5\u7528\u5176\u6765\u5b9e\u73b0\u7b80\u5355\u7684\u6b7b\u5faa\u73af\u3002<\/p>\n\n\n\n
LOOP\u53ef\u4ee5\u914d\u5408\u4ee5\u4e0b\u4e24\u4e2a\u8bed\u53e5\u4f7f\u7528\uff1a<\/p>\n\n\n\n
LEAVE \uff1a\u914d\u5408\u5faa\u73af\u4f7f\u7528\uff0c\u9000\u51fa\u5faa\u73af\u3002\u8df3\u51fa\u672c\u5c42\u5faa\u73af<\/p>\n\n\n\n
ITERATE\uff1a\u5fc5\u987b\u7528\u5728\u5faa\u73af\u4e2d\uff0c\u4f5c\u7528\u662f\u8df3\u8fc7\u5f53\u524d\u5faa\u73af\u5269\u4e0b\u7684\u8bed\u53e5\uff0c\u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u6b21\u5faa\u73af\u3002\u8df3\u51fa\u672c\u6b21\u5faa\u73af<\/p>\n\n\n\n
leave \u548clterate\uff0c\u7c7b\u4f3cbreak\u548ccontinue\uff0c\u524d\u8005\u8df3\u51fa\u672c\u5c42\u5faa\u73af\uff0c\u540e\u8005\u8df3\u51fa\u672c\u6b21\u5faa\u73af<\/p>\n\n\n\n
\u8bed\u6cd5<\/strong><\/p>\n\n\n\n
[begin_label:] LOOP\n    SQL\u903b\u8f91...\nEND LOOP [end_label];\n\nLEAVE label; -- \u9000\u51fa\u6307\u5b9a\u6807\u8bb0\u7684\u5faa\u73af\u4f53\nITERATE label; -- \u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u6b21\u5faa\u73af\n\u4e0a\u8ff0\u8bed\u6cd5\u4e2d\u51fa\u73b0\u7684 begin_label\uff0cend_label\uff0clabel \u6307\u7684\u90fd\u662f\u6211\u4eec\u6240\u81ea\u5b9a\u4e49\u7684\u6807\u8bb0<\/code><\/pre>\n\n\n\n
\u6848\u4f8b\u4e00<\/p>\n\n\n\n
\u8ba1\u7b97\u4ece1\u7d2f\u52a0\u5230n\u7684\u503c\uff0cn\u4e3a\u4f20\u5165\u7684\u53c2\u6570\u503c<\/p>\n\n\n\n
-- A. \u5b9a\u4e49\u5c40\u90e8\u53d8\u91cf, \u8bb0\u5f55\u7d2f\u52a0\u4e4b\u540e\u7684\u503c;\n-- B. \u6bcf\u5faa\u73af\u4e00\u6b21, \u5c31\u4f1a\u5bf9n\u8fdb\u884c-1 , \u5982\u679cn\u51cf\u52300, \u5219\u9000\u51fa\u5faa\u73af ----> leave xx\ncreate procedure p9(in n int)\nbegin\n    declare total int default 0;\n\n    sum:loop\n        if n <=0 then\n            leave sum;      ##\u8df3\u51fa\u672c\u53c2\u5faa\u73af\uff0c\u56e0\u4e3a\u7ed9\u5b9an\u503c\u4e0d\u7b26\n        end if;\n\n        set total := total + n;\n        set n := n -1;\n    end loop;\n    select total;\nend;\n\ncall p9(15);<\/code><\/pre>\n\n\n\n
\u6848\u4f8b\u4e8c<\/p>\n\n\n\n
\u8ba1\u7b97\u4ece1\u5230n\u4e4b\u95f4\u7684\u5076\u6570<\/strong>\u7d2f\u52a0\u7684\u503c\uff0cn\u4e3a\u4f20\u5165\u7684\u53c2\u6570\u503c\u3002<\/p>\n\n\n\n
\n-- A. \u5b9a\u4e49\u5c40\u90e8\u53d8\u91cf, \u8bb0\u5f55\u7d2f\u52a0\u4e4b\u540e\u7684\u503c;\n-- B. \u6bcf\u5faa\u73af\u4e00\u6b21, \u5c31\u4f1a\u5bf9n\u8fdb\u884c-1 , \u5982\u679cn\u51cf\u52300, \u5219\u9000\u51fa\u5faa\u73af ----> leave xx\n-- C. \u5982\u679c\u5f53\u6b21\u7d2f\u52a0\u7684\u6570\u636e\u662f\u5947\u6570, \u5219\u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u6b21\u5faa\u73af. --------> iterate xx\n\ncreate procedure p11(in n int)\nbegin\n    declare total int default 0;\n\n    sum:loop\n        if n <=0 then\n            leave sum;\n        end if;\n\n        if n%2 = 1 then\n            set n := n-1;\n            iterate sum;\n        end if;\n\n        set total := total + n;\n        set n := n -1;\n    end loop;\n    select total;\nend;\n\ncall p11(10);<\/code><\/pre>\n\n\n\n
\u6e38\u6807<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
\u6e38\u6807\uff08CURSOR\uff09\u662f\u7528\u6765\u5b58\u50a8\u67e5\u8be2\u7ed3\u679c\u96c6\u7684\u6570\u636e\u7c7b\u578b , \u5728\u5b58\u50a8\u8fc7\u7a0b\u548c\u51fd\u6570\u4e2d\u53ef\u4ee5\u4f7f\u7528\u6e38\u6807\u5bf9\u7ed3\u679c\u96c6\u8fdb<\/p>\n\n\n\n
\u884c\u5faa\u73af\u7684\u5904\u7406\u3002\u6e38\u6807\u7684\u4f7f\u7528\u5305\u62ec\u6e38\u6807\u7684\u58f0\u660e\u3001OPEN\u3001FETCH \u548c CLOSE\uff0c\u5176\u8bed\u6cd5\u5206\u522b\u5982\u4e0b<\/p>\n\n\n\n
\u58f0\u660e\u6e38\u6807\nDECLARE \u6e38\u6807\u540d\u79f0 CURSOR FOR \u67e5\u8be2\u8bed\u53e5 ;\n\n\u6253\u5f00\u6e38\u6807\nOPEN \u6e38\u6807\u540d\u79f0 ; \n\n\n\u83b7\u53d6\u6e38\u6807\u8bb0\u5f55\nFETCH \u6e38\u6807\u540d\u79f0 INTO \u53d8\u91cf [, \u53d8\u91cf ] ;\n\n\u5173\u95ed\u6e38\u6807\nCLOSE \u6e38\u6807\u540d\u79f0 ;<\/code><\/pre>\n\n\n\n
\u6848\u4f8b<\/p>\n\n\n\n
\u6839\u636e\u4f20\u5165\u7684\u53c2\u6570uage\uff0c\u6765\u67e5\u8be2\u7528\u6237\u8868tb_user\u4e2d\uff0c\u6240\u6709\u7684\u7528\u6237\u5e74\u9f84\u5c0f\u4e8e\u7b49\u4e8euage\u7684\u7528\u6237\u59d3\u540d<\/p>\n\n\n\n
\uff08name\uff09\u548c\u4e13\u4e1a\uff08profession\uff09\uff0c\u5e76\u5c06\u7528\u6237\u7684\u59d3\u540d\u548c\u4e13\u4e1a\u63d2\u5165\u5230\u6240\u521b\u5efa\u7684\u4e00\u5f20\u65b0\u8868<\/p>\n\n\n\n
-- \u903b\u8f91:\n-- A. \u58f0\u660e\u6e38\u6807, \u5b58\u50a8\u67e5\u8be2\u7ed3\u679c\u96c6\n-- B. \u51c6\u5907: \u521b\u5efa\u8868\u7ed3\u6784\n-- C. \u5f00\u542f\u6e38\u6807\n-- D. \u83b7\u53d6\u6e38\u6807\u4e2d\u7684\u8bb0\u5f55\n-- E. \u63d2\u5165\u6570\u636e\u5230\u65b0\u8868\u4e2d\n-- F. \u5173\u95ed\u6e38\u6807\n\n\n\ncreate procedure p12(in uage int)     \nbegin\n    declare uname varchar(100);   \n    declare upro varchar(100);     ##\u666e\u901a\u58f0\u660e\u8981\u5728\u6e38\u6807\u58f0\u660e\u4e4b\u524d\n    declare u_cursor cursor for<\/strong>  select name,profession from tb_user where age < uage;    ##\u58f0\u660e\u6e38\u6807, \u5b58\u50a8\u67e5\u8be2\u7ed3\u679c\u96c6 \u5c06 tb_user\u7684\u6570\u636e\u5b58\u50a8\u5230u_cursor\u4e2d\n\n    drop table if exists tb_user_pro;     ##\u521b\u9020\u8868\u7ed3\u6784\uff0c\u4e3a\u6570\u636e\u904d\u5386\u5230tb_user_pro\u505a\u51c6\u5907\n    create table if not exists tb_user_pro(    \n        id int primary key auto_increment,\n        name varchar(100),\n        profession varchar(100)\n    );\n\n\n    open u_cursor;                  ##\u5f00\u542f\u6e38\u6807\n    while true do                   \n        fetch u_cursor into uname,upro;  ##\u904d\u5386u_cursor\u6570\u636e\uff0c\u5c06\u6570\u636e\u904d\u5386\u5230tb_user_pro\u4e2d\uff0c\u83b7\u53d6\u6e38\u6807\u4e2d\u7684\u8bb0\u5f55\n        insert into tb_user_pro values (null,uname,upro);   ##\u63d2\u5165\u6570\u636e\u5230tb_user_pro\u4e2d\n    end while;\n\n    close u_cursor;    #\u5173\u95ed\u6e38\u6807\nend;\n\ncall p12(40);            ##\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b\uff0c\u4f1a\u751f\u6210\u4e00\u4e2a\u65b0\u8868t_user_pro<\/code><\/pre>\n\n\n\n
\u4f46\u662f\u901a\u8fc7\u6b64\u8fc7\u7a0b\uff0c\u4f1a\u62a5\u9519\uff0c\u7ffb\u8bd1\u4e3a\uff1a\u6ca1\u6709\u6570\u636e\u53bb\u83b7\u53d6\u904d\u5386\u4e86\uff0c\u662f\u56e0\u4e3a\u6211\u4eec\u7684\u5faa\u73af\u6ca1\u6709\u5b9a\u4e49\u6761\u4ef6\uff0c\u6570\u636e\u5e93\u4e0d\u77e5\u9053\u5982\u4f55\u7ed3\u675f\u5faa\u73af\uff0c\u8fd9\u4e2a\u62a5\u9519\u901a\u5e38\u4f7f\u7528\u6761\u4ef6\u5904\u7406\u7a0b\u5e8f<\/strong>\u6765\u89e3\u51b3<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6761\u4ef6\u5904\u7406\u7a0b\u5e8f<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
\u6761\u4ef6\u5904\u7406\u7a0b\u5e8f\uff08Handler\uff09\u53ef\u4ee5\u7528\u6765\u5b9a\u4e49\u5728\u6d41\u7a0b\u63a7\u5236\u7ed3\u6784\u6267\u884c\u8fc7\u7a0b\u4e2d\u9047\u5230\u95ee\u9898\u65f6\u76f8\u5e94\u7684\u5904\u7406\u6b65\u9aa4\u3002\u5177\u4f53<\/p>\n\n\n\n
\u8bed\u6cd5\u4e3a<\/p>\n\n\n\n
DECLARE handler_action HANDLER FOR condition_value [, condition_value]\n... statement ;\nhandler_action \u7684\u53d6\u503c\uff1a\n    CONTINUE: \u7ee7\u7eed\u6267\u884c\u5f53\u524d\u7a0b\u5e8f\n    EXIT: \u7ec8\u6b62\u6267\u884c\u5f53\u524d\u7a0b\u5e8f\n\ncondition_value \u7684\u53d6\u503c\uff1a\n    SQLSTATE sqlstate_value: \u72b6\u6001\u7801\uff0c\u5982 02000\n    SQLWARNING: \u6240\u6709\u4ee501\u5f00\u5934\u7684SQLSTATE\u4ee3\u7801\u7684\u7b80\u5199\n    NOT FOUND: \u6240\u6709\u4ee502\u5f00\u5934\u7684SQLSTATE\u4ee3\u7801\u7684\u7b80\u5199\n    SQLEXCEPTION: \u6240\u6709\u6ca1\u6709\u88abSQLWARNING \u6216 NOT FOUND\u6355\u83b7\u7684SQLSTATE\u4ee3\u7801\u7684\u7b80\u5199<\/code><\/pre>\n\n\n\n
\u7531\u4e0a\u8ff0\u62a5\u9519\u6211\u4eec\u53ef\u4ee5\u77e5\u9053\u539f\u56e0\u662f\u627e\u4e0d\u5230\u6570\u636e\u62a5\u951902000\uff0c\u5219\u9009\u62e9SQLSTATUE\uff0c\u6216\u8005NOT FOUND\u6765\u89e3\u51b3\u5f53\u524d\u95ee\u9898<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
create procedure p12(in uage int)\nbegin\n    declare uname varchar(100);\n    declare upro varchar(100);\n    declare u_cursor cursor for  select name,profession from tb_user where age < uage;\n    declare exit handler for SQLSTATE  '02000' close u_cursor;<\/strong>    ## \u58f0\u660e\u6761\u4ef6\u7a0b\u5e8f\uff0c\u9700\u8981\u6267\u884c\u9000\u51fa\u64cd\u4f5c\uff0c\u5f53\u62a5\u951902000\u5f02\u5e38\u7684\u65f6\u5019\uff0c\u5e76\u540c\u65f6\u5173\u95ed\u6e38\u6807\n\n    drop table if exists tb_user_pro;\n    create table if not exists tb_user_pro(\n        id int primary key auto_increment,\n        name varchar(100),\n        profession varchar(100)\n    );\n\n\n    open u_cursor;\n    while true do\n        fetch u_cursor into uname,upro;\n        insert into tb_user_pro values (null,uname,upro);\n    end while;\n\n    close u_cursor;\nend;<\/code><\/pre>\n\n\n\n
\u66f4\u591a\u53ef\u53c2\u8003\uff1a<\/p>\n\n\n\n
Mysql\u5b98\u65b9\u6587\u6863<\/a><\/p>\n\n\n\n
\u5b58\u50a8\u51fd\u6570<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
\u5b58\u50a8\u51fd\u6570\u662f\u6709\u8fd4\u56de\u503c\u7684\u5b58\u50a8\u8fc7\u7a0b\uff0c\u5b58\u50a8\u51fd\u6570\u7684\u53c2\u6570\u53ea\u80fd\u662fIN\u7c7b\u578b\u7684\u3002\u5177\u4f53\u8bed\u6cd5\u5982\u4e0b<\/p>\n\n\n\n
CREATE FUNCTION \u5b58\u50a8\u51fd\u6570\u540d\u79f0 ([ \u53c2\u6570\u5217\u8868 ])\nRETURNS type [characteristic ...]\nBEGIN\n    -- SQL\u8bed\u53e5\n    RETURN ...;\nEND ;\n\ncharacteristic\u8bf4\u660e\uff1a\ndeterministic\uff1a\u76f8\u540c\u7684\u8f93\u5165\u53c2\u6570\u603b\u662f\u4ea7\u751f\u76f8\u540c\u7684\u7ed3\u679c\nnot sql \uff1a\u4e0d\u5305\u542b SQL \u8bed\u53e5\u3002\nreads sql data\uff1a\u5305\u542b\u8bfb\u53d6\u6570\u636e\u7684\u8bed\u53e5\uff0c\u4f46\u4e0d\u5305\u542b\u5199\u5165\u6570\u636e\u7684\u8bed\u53e5<\/code><\/pre>\n\n\n\n
\u6ce8\u610f<\/p>\n\n\n\n
\u5728mysql8.0\u4ee5\u540e\uff0c\u4e8c\u8fdb\u5236\u65e5\u5fd7\u9ed8\u8ba4\u5f00\u542f\uff0c\u5fc5\u987b\u63cf\u8ff0\u7279\u6027(characteristic)<\/p>\n\n\n\n
\u5b58\u50a8\u51fd\u6570\u5fc5\u987b\u8981\u6709\u8fd4\u56de\u503c<\/p>\n\n\n\n
\u5b58\u50a8\u51fd\u6570\u7528\u7684\u6bd4\u8f83\u5c11\uff0c\u5b58\u50a8\u8fc7\u7a0b\u7528\u7684\u8f83\u591a<\/p>\n\n\n\n
\u6848\u4f8b<\/p>\n\n\n\n
\u8ba1\u7b97\u4ece1\u7d2f\u52a0\u5230n\u7684\u503c\uff0cn\u4e3a\u4f20\u5165\u7684\u53c2\u6570\u503c<\/p>\n\n\n\n
create function fun01( n int)\nreturns<\/strong> int<\/strong> deterministic<\/strong>\nbegin\n    declare total int default 0;\n\n    while n >0 do\n        set total := total +n;\n        set n := n-1;\n    end while;\n\n    return total;\nend;\n\nselect fun01(10000);<\/code><\/pre>\n\n\n\n
\u89e6\u53d1\u5668<\/strong><\/h2>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/h3>\n\n\n\n
\u89e6\u53d1\u5668\u662f\u4e0e\u8868\u6709\u5173\u7684\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u6307\u5728insert\/update\/delete\u4e4b\u524d(BEFORE)\u6216\u4e4b\u540e(AFTER)\uff0c\u89e6\u53d1\u5e76\u6267\u884c\u89e6\u53d1\u5668\u4e2d\u5b9a\u4e49\u7684SQL\u8bed\u53e5\u96c6\u5408\u3002\u89e6\u53d1\u5668\u7684\u8fd9\u79cd\u7279\u6027\u53ef\u4ee5\u534f\u52a9\u5e94\u7528\u5728\u6570\u636e\u5e93\u7aef\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027, \u65e5\u5fd7\u8bb0\u5f55 , \u6570\u636e\u6821\u9a8c\u7b49\u64cd\u4f5c \u3002<\/p>\n\n\n\n
\u4f7f\u7528\u522b\u540dOLD\u548cNEW\u6765\u5f15\u7528\u89e6\u53d1\u5668\u4e2d\u53d1\u751f\u53d8\u5316\u7684\u8bb0\u5f55\u5185\u5bb9\uff0c\u8fd9\u4e0e\u5176\u4ed6\u7684\u6570\u636e\u5e93\u662f\u76f8\u4f3c\u7684\u3002\u73b0\u5728\u89e6\u53d1\u5668\u8fd8<\/p>\n\n\n\n
\u53ea\u652f\u6301\u884c\u7ea7\u89e6\u53d1<\/strong>\uff0c\u4e0d\u652f\u6301\u8bed\u53e5\u7ea7\u89e6\u53d1\u3002<\/p>\n\n\n\n
\u89e6\u53d1\u5668\u7c7b\u578b<\/strong><\/td>NEW \u548c OLD<\/strong><\/td><\/tr>
INSERT \u578b\u89e6\u53d1\u5668<\/td>NEW \u8868\u793a\u5c06\u8981\u6216\u8005\u5df2\u7ecf\u65b0\u589e\u7684\u6570\u636e<\/td><\/tr>
UPDATE \u578b\u89e6\u53d1\u5668<\/td>OLD \u8868\u793a\u4fee\u6539\u4e4b\u524d\u7684\u6570\u636e , NEW \u8868\u793a\u5c06\u8981\u6216\u5df2\u7ecf\u4fee\u6539\u540e\u7684\u6570\u636e<\/td><\/tr>
DELETE \u578b\u89e6\u53d1\u5668<\/td>OLD \u8868\u793a\u5c06\u8981\u6216\u8005\u5df2\u7ecf\u5220\u9664\u7684\u6570\u636e<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
\u521b\u5efa\nCREATE TRIGGER trigger_name\nBEFORE\/AFTER INSERT\/UPDATE\/DELETE\nON tbl_name FOR EACH ROW -- \u884c\u7ea7\u89e6\u53d1\u5668\nBEGIN\n    trigger_stmt ;\nEND;\n\n\u67e5\u770b\nSHOW TRIGGERS ;\n\n\u5220\u9664\nDROP TRIGGER [schema_name.]trigger_name ; -- \u5982\u679c\u6ca1\u6709\u6307\u5b9a schema_name\uff0c\u9ed8\u8ba4\u4e3a\u5f53\u524d\u6570\n\u636e\u5e93<\/code><\/pre>\n\n\n\n
\u6848\u4f8b<\/strong><\/h3>\n\n\n\n
\u901a\u8fc7\u89e6\u53d1\u5668\u8bb0\u5f55 tb_user \u8868\u7684\u6570\u636e\u53d8\u66f4\u65e5\u5fd7\uff0c\u5c06\u53d8\u66f4\u65e5\u5fd7\u63d2\u5165\u5230\u65e5\u5fd7\u8868user_logs\u4e2d, \u5305\u542b\u589e\u52a0,<\/p>\n\n\n\n
\u4fee\u6539 , \u5220\u9664 ;<\/p>\n\n\n\n
\u63d2\u5165\u6570\u636e\u89e6\u53d1\u5668<\/strong><\/h4>\n\n\n\n
create trigger<\/strong> tb_user_insert_trigger         ##\u6307\u5b9a\u89e6\u53d1\u5668\u540d\u79f0tb_user_insert_trigger\n    after insert on<\/strong> tb_user for each row   <\/strong>        ##\u6307\u5b9a\u5728sql\u8bed\u53e5\u4e4b\u540e\u89e6\u53d1after\uff0c\u7c7b\u578b\u4e3ainsert\u6dfb\u52a0\uff0c\u6307\u5b9a\u4e3a\u884c\u89e6\u53d1\u5668 each row \n\nbegin\n    insert into user_logs(id, operation, operate_time, operate_id, operate_params) values\n    (null, 'insert', now(), new.id, concat('\u63d2\u5165\u7684\u6570\u636e\u5185\u5bb9\u4e3a:id=',new.id,',name=',new.name, ', phone=', NEW.phone, ', email=', NEW.email, ',profession=', NEW.profession));  ##new\u4e3a\u65b0\u6dfb\u52a0\u6570\u636e\uff0cinsert\u4e5f\u53ea\u53ef\u4ee5new\nend;<\/code><\/pre>\n\n\n\n
\u9a8c\u8bc1<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5f53\u6211\u4eec\u5728insert\u89e6\u53d1\u5668\u4e2d\uff0cuser\u8868\u4e2d\u6dfb\u52a0\u6570\u636e\u7684\u65f6\u5019\uff0c\u5728logs\u8868\uff0cuser\u8868\u4e2d\u4f1a\u6dfb\u52a0\u76f8\u5e94\u8bb0\u5f55<\/p>\n\n\n\n
insert into tb_user(id, name, phone, email, profession, age, gender, status, createtime)\nVALUES (25,'\u4e8c\u7687\u5b50','18809091212','erhuangzi@163.com','\u8f6f\u4ef6\u5de5\u7a0b',23,'1','1',now());<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4fee\u6539\u6570\u636e\u89e6\u53d1\u5668<\/strong><\/h4>\n\n\n\n
create trigger tb_user_update_trigger\n    after update on<\/strong> tb_user for each row <\/strong>    ##\u6307\u5b9a\u5728sql\u8bed\u53e5\u4e4b\u540e\u89e6\u53d1after\uff0c\u7c7b\u578b\u4e3aupdate\u4fee\u6539\uff0c\u6307\u5b9a\u4e3a\u884c\u89e6\u53d1\u5668 each row\n\nbegin\n    insert into user_logs(id, operation, operate_time, operate_id, operate_params) VALUES\n    (null, 'update', now(), new.id,\n        concat('\u66f4\u65b0\u4e4b\u524d\u7684\u6570\u636e: id=',old.id,',name=',old.name, ', phone=',old.phone, ', email=', old.email, ', profession=', old.profession,\n            ' | \u66f4\u65b0\u4e4b\u540e\u7684\u6570\u636e: id=',new.id,',name=',new.name, ', phone=',NEW.phone, ', email=', NEW.email, ', profession=', NEW.profession));  ##old\u4e3a\u65e7\u6570\u636e\uff0cupdate\u80fd\u6307\u5b9anew\uff0c\u4e5f\u53efold\nend;<\/code><\/pre>\n\n\n\n
\u5f53\u6211\u4eec\u4fee\u6539user\u8868\u4e2d\u7684\u6570\u636e\u7684\u65f6\u5019\uff0c\u5728logs\u8868\uff0cuser\u8868\u4e2d\u4f1a\u6dfb\u52a0\u76f8\u5e94\u8bb0\u5f55<\/p>\n\n\n\n
update tb_user set profession = '\u4f1a\u8ba1' where id <= 5;\n<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5220\u9664\u6570\u636e\u89e6\u53d1\u5668<\/strong><\/h4>\n\n\n\n
create trigger tb_user_delete_trigger
after delete on tb_user for each row  ##\u6307\u5b9a\u5728sql\u8bed\u53e5\u4e4b\u540e\u89e6\u53d1after\uff0c\u7c7b\u578b\u4e3adelete\u5220\u9664\uff0c\u6307\u5b9a\u4e3a\u884c\u89e6\u53d1\u5668 each row
begin
    insert into user_logs(id, operation, operate_time, operate_id, operate_params)
    VALUES
    (null, 'delete', now(), old.id,concat('\u5220\u9664\u4e4b\u524d\u7684\u6570\u636e: id=',old.id,',name=',old.name, ', phone=',old.phone, ', email=', old.email, ', profession=', old.profession));  ##\u5220\u9664\u53ea\u80fd\u6307\u5b9aold\u65e7\u6570\u636e
end;<\/pre>\n\n\n\n
\u67e5\u770b\u5df2\u6709\u7684\u6240\u6709\u89e6\u53d1\u5668(insert,update,delete)<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u67e5\u770b\u5220\u9664\u65e5\u5fd7<\/p>\n\n\n\n
delete from tb_user where tb_user.id = 25;<\/code><\/pre>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u9501<\/strong><\/h2>\n\n\n\n
\u6982\u8ff0<\/strong><\/h3>\n\n\n\n
\u9501\u662f\u8ba1\u7b97\u673a\u534f\u8c03\u591a\u4e2a\u8fdb\u7a0b\u6216\u7ebf\u7a0b\u5e76\u53d1\u8bbf\u95ee\u67d0\u4e00\u8d44\u6e90\u7684\u673a\u5236\u3002\u5728\u6570\u636e\u5e93\u4e2d\uff0c\u9664\u4f20\u7edf\u7684\u8ba1\u7b97\u8d44\u6e90\uff08CPU\u3001<\/p>\n\n\n\n
RAM\u3001I\/O\uff09\u7684\u4e89\u7528\u4ee5\u5916\uff0c\u6570\u636e\u4e5f\u662f\u4e00\u79cd\u4f9b\u8bb8\u591a\u7528\u6237\u5171\u4eab\u7684\u8d44\u6e90\u3002\u5982\u4f55\u4fdd\u8bc1\u6570\u636e\u5e76\u53d1\u8bbf\u95ee\u7684\u4e00\u81f4\u6027\u3001\u6709<\/p>\n\n\n\n
\u6548\u6027\u662f\u6240\u6709\u6570\u636e\u5e93\u5fc5\u987b\u89e3\u51b3\u7684\u4e00\u4e2a\u95ee\u9898\uff0c\u9501\u51b2\u7a81\u4e5f\u662f\u5f71\u54cd\u6570\u636e\u5e93\u5e76\u53d1\u8bbf\u95ee\u6027\u80fd\u7684\u4e00\u4e2a\u91cd\u8981\u56e0\u7d20\u3002\u4ece\u8fd9\u4e2a<\/p>\n\n\n\n
\u89d2\u5ea6\u6765\u8bf4\uff0c\u9501\u5bf9\u6570\u636e\u5e93\u800c\u8a00\u663e\u5f97\u5c24\u5176\u91cd\u8981\uff0c\u4e5f\u66f4\u52a0\u590d\u6742<\/p>\n\n\n\n
MySQL\u4e2d\u7684\u9501\uff0c\u6309\u7167\u9501\u7684\u7c92\u5ea6\u5206\uff0c\u5206\u4e3a\u4ee5\u4e0b\u4e09\u7c7b<\/strong>\uff1a<\/p>\n\n\n\n
\u5168\u5c40\u9501\uff1a\u9501\u5b9a\u6570\u636e\u5e93\u4e2d\u7684\u6240\u6709\u8868\u3002<\/p>\n\n\n\n
\u8868\u7ea7\u9501\uff1a\u6bcf\u6b21\u64cd\u4f5c\u9501\u4f4f\u6574\u5f20\u8868\u3002<\/p>\n\n\n\n
\u884c\u7ea7\u9501\uff1a\u6bcf\u6b21\u64cd\u4f5c\u9501\u4f4f\u5bf9\u5e94\u7684\u884c\u6570\u636e\u3002<\/p>\n\n\n\n
\u5168\u5c40\u9501<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/strong><\/h4>\n\n\n\n
\u5168\u5c40\u9501\u5c31\u662f\u5bf9\u6574\u4e2a\u6570\u636e\u5e93\u5b9e\u4f8b\u52a0\u9501\uff0c\u52a0\u9501\u540e\u6574\u4e2a\u5b9e\u4f8b\u5c31\u5904\u4e8e\u53ea\u8bfb\u72b6\u6001\uff0c\u540e\u7eed\u7684DML\u7684\u5199\u8bed\u53e5\uff0cDDL\u8bed\u53e5\uff0c\u5df2\u7ecf\u66f4\u65b0\u64cd\u4f5c\u7684\u4e8b\u52a1\u63d0\u4ea4\u8bed\u53e5\u90fd\u5c06\u88ab\u963b\u585e\u3002\u4f46\u662f\u53ef\u4ee5\u6267\u884cDQL<\/p>\n\n\n\n
\u5176\u5178\u578b\u7684\u4f7f\u7528\u573a\u666f\u662f\u505a\u5168\u5e93\u7684\u903b\u8f91\u5907\u4efd\uff0c\u5bf9\u6240\u6709\u7684\u8868\u8fdb\u884c\u9501\u5b9a\uff0c\u4ece\u800c\u83b7\u53d6\u4e00\u81f4\u6027\u89c6\u56fe\uff0c\u4fdd\u8bc1\u6570\u636e\u7684\u5b8c\u6574<\/p>\n\n\n\n
\u6027<\/p>\n\n\n\n
\u4e3a\u4f55\u9700\u8981\u5168\u5c40\u9501\uff1f<\/p>\n\n\n\n
\u4f8b\u5982\u5728\u5b9e\u9645\u60c5\u51b5\u4e2d\uff0c\u6211\u4eec\u9700\u8981\u8fdb\u884c\u5168\u90e8\u903b\u8f91\u6570\u636e\u5907\u4efd\uff0c\u5f53\u6ca1\u6709\u9501\u7684\u65f6\u5019\uff0c\u6211\u4eec\u5bf9\u5e93\u8868\u8fdb\u884c\u5907\u4efd\u7684\u540c\u65f6\uff0c\u6570\u636e\u662f\u5728\u589e\u52a0\u7684\uff0c\u662f\u5728\u4e0d\u505c\u5904\u7406\u7684\uff0c\u82e5\u5728\u4e24\u4e2a\u76f8\u5173\u8054\u7684\u8868\u4e2d\uff0c\u524d\u8868\u8fdb\u884c\u4e86\u5907\u4efd\uff0c\u7136\u540e\u53c8\u5728\u4e24\u8868\u6dfb\u52a0\u4e86\u6570\u636e\u8fdb\u5165\uff0c\u6211\u4eec\u6b64\u65f6\u5728\u6dfb\u52a0\u6570\u636e\u540e\u5907\u4efd\u7b2c\u4e8c\u5f20\u8868\uff0c\u90a3\u4e48\u4e24\u8868\u7684\u6570\u636e\u662f\u4e0d\u4e00\u81f4\u7684\u3002\u6240\u4ee5\u6211\u4eec\u9700\u8981\u5168\u5c40\u9501\u9501\u5b9a\u5168\u5c40\u5907\u4efd\u6570\u636e\u4fdd\u6301\u6570\u636e\u4e00\u81f4\u6027<\/p>\n\n\n\n
\u5bf9\u6570\u636e\u5e93\u8fdb\u884c\u8fdb\u884c\u903b\u8f91\u5907\u4efd\u4e4b\u524d\uff0c\u5148\u5bf9\u6574\u4e2a\u6570\u636e\u5e93\u52a0\u4e0a\u5168\u5c40\u9501\uff0c\u4e00\u65e6\u52a0\u4e86\u5168\u5c40\u9501\u4e4b\u540e\uff0c\u5176\u4ed6\u7684DDL\u3001DML\u5168\u90e8\u90fd\u5904\u4e8e\u963b\u585e\u72b6\u6001\uff0c\u4f46\u662f\u53ef\u4ee5\u6267\u884cDQL\u8bed\u53e5\uff0c\u4e5f\u5c31\u662f\u5904\u4e8e\u53ea\u8bfb\u72b6\u6001\uff0c\u800c\u6570\u636e\u5907\u4efd\u5c31\u662f\u67e5\u8be2\u64cd\u4f5c\u3002\u90a3\u4e48\u6570\u636e\u5728\u8fdb\u884c\u903b\u8f91\u5907\u4efd\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\u5c31\u662f\u4e0d\u4f1a\u53d1\u751f\u53d8\u5316\u7684\uff0c\u8fd9\u6837\u5c31\u4fdd\u8bc1\u4e86\u6570\u636e\u7684\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027<\/p>\n\n\n\n
\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
\u52a0\u5168\u5c40\u9501<\/p>\n\n\n\n
flush tables with read lock ;\n\n##\u6ce8\u610f\u52a0\u5168\u5c40\u9501\u548c\u91ca\u653e\u9501\uff0c\u5fc5\u987b\u5728\u540c\u4e00\u7a97\u53e3\u4e0b\uff0c\u82e5\u5728\u5f00\u9501\u671f\u95f4\u63a8\u51fa\u4e86\u6570\u636e\u5e93\uff0c\u90a3\u4e48\u8be5\u9501\u4f1a\u5931\u6548<\/code><\/pre>\n\n\n\n
\u6570\u636e\u5907\u4efd<\/p>\n\n\n\n
mysqldump -uroot \u2013p1234 itcast > itcast.sql(\u9009\u62e9\u5907\u4efd\u76ee\u5f55)\n\n##\u6ce8\u610fmysqldump\u5e76\u4e0d\u662fmysql\u4e2d\u7684\u8bed\u6cd5\uff0c\u800c\u662f\u4e00\u4e2abin\u547d\u4ee4\uff0c\u6240\u4ee5\u9700\u8981\u9000\u51fa\u7a97\u53e3\u6267\u884c<\/code><\/pre>\n\n\n\n
\u91ca\u653e\u9501<\/p>\n\n\n\n
unlock tables ;<\/code><\/pre>\n\n\n\n
\u7279\u70b9<\/strong><\/h4>\n\n\n\n
\u6570\u636e\u5e93\u4e2d\u52a0\u5168\u5c40\u9501\uff0c\u662f\u4e00\u4e2a\u6bd4\u8f83\u91cd\u7684\u64cd\u4f5c\uff0c\u5b58\u5728\u4ee5\u4e0b\u95ee\u9898\uff1a<\/p>\n\n\n\n
\u5982\u679c\u5728\u4e3b\u5e93\u4e0a\u5907\u4efd\uff0c\u90a3\u4e48\u5728\u5907\u4efd\u671f\u95f4\u90fd\u4e0d\u80fd\u6267\u884c\u66f4\u65b0\uff0c\u4e1a\u52a1\u57fa\u672c\u4e0a\u5c31\u5f97\u505c\u6446\u3002<\/p>\n\n\n\n
\u5982\u679c\u5728\u4ece\u5e93\u4e0a\u5907\u4efd\uff0c\u90a3\u4e48\u5728\u5907\u4efd\u671f\u95f4\u4ece\u5e93\u4e0d\u80fd\u6267\u884c\u4e3b\u5e93\u540c\u6b65\u8fc7\u6765\u7684\u4e8c\u8fdb\u5236\u65e5\u5fd7\uff08binlog\uff09\uff0c\u4f1a\u5bfc\u81f4\u4e3b\u4ece\u5ef6\u8fdf\u3002<\/p>\n\n\n\n
\u5728InnoDB\u5f15\u64ce\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u5907\u4efd\u65f6\u52a0\u4e0a\u53c2\u6570 –single-transaction \u53c2\u6570\u6765\u5b8c\u6210\u4e0d\u52a0\u9501\u7684\u4e00\u81f4\u6027\u6570\u636e\u5907\u4efd<\/p>\n\n\n\n
mysqldump --single-transaction -uroot \u2013p123456 itcast > itcast.sql\n##\u6dfb\u52a0--single-transaction\u4e4b\u540e\u4e0d\u9700\u8981\u5728\u5f00\u542f\u5168\u5c40\u9501<\/code><\/pre>\n\n\n\n
\u8868\u9501<\/strong><\/h3>\n\n\n\n
\u5bf9\u4e8e\u8868\u9501\uff0c\u5206\u4e3a\u4e24\u7c7b\uff1a<\/p>\n\n\n\n
\u8868\u5171\u4eab\u8bfb\u9501\uff08read lock\uff09<\/p>\n\n\n\n
\u8868\u72ec\u5360\u5199\u9501\uff08write lock\uff09<\/p>\n\n\n\n
\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
\u52a0\u9501\nlock tables \u8868\u540d... read\/write\n\n\u91ca\u653e\u9501\nunlock tables \/ \u5ba2\u6237\u7aef\u65ad\u5f00\u8fde\u63a5<\/code><\/pre>\n\n\n\n
\u7279\u70b9<\/strong><\/h4>\n\n\n\n
\u8bfb\u9501<\/strong><\/p>\n\n\n\n
\u5728\u8868\u8bfb\u9501\u5185\uff0c\u82e5\u5728\u5ba2\u670d\u7aef\u4e00\u5185\u5f00\u542f\u4e86\u8868\u8bfb\u9501\uff0c\u90a3\u4e48\u7528\u6237\u4e00\u53ef\u4ee5\u6267\u884cDQL\u8bed\u53e5\uff0c\u800c\u4e0d\u80fd\u6267\u884cDDL\/DML\u8bed\u53e5\uff0c\u5728\u5ba2\u6237\u7aef\u4e8c\u5185\uff0c\u7528\u6237\u4e8c\u53ef\u4ee5\u6267\u884cDQL\u8bed\u53e5\uff0c\u800c\u4e0d\u80fd\u6267\u884cDDL\/DML\u8bed\u53e5\uff0c\u603b\u7ed3\u5c31\u662f\u5728\u8bfb\u9501\u5185\uff0c\u53ef\u4ee5\u8bfb\u53d6\u6570\u636e(DQL)\uff0c\u800c\u4e0d\u80fd\u5199\u5165\u4fee\u6539\u6570\u636e\u7b49(DDL\/DML)<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5199\u9501<\/strong><\/p>\n\n\n\n
\u5728\u8868\u5199\u9501\u5185\uff0c\u82e5\u5728\u5ba2\u670d\u7aef\u4e00\u5185\u5f00\u542f\u4e86\u8868\u5199\u9501\uff0c\u90a3\u4e48\u7528\u6237\u4e00\u53ef\u4ee5\u6267\u884cDQL,DDL\/DML\uff0c\u53ef\u4ee5\u8bfb\u5199\uff0c\u4f46\u662f\u5728\u5ba2\u6237\u7aef\u4e8c\u4e2d\uff0c\u7528\u6237\u4e8c\u65e2\u4e0d\u80fd\u6267\u884cDQL\uff0c\u4e5f\u65e0\u6cd5\u6267\u884cDDL\/DML\u8bed\u53e5<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u603b\u7ed3<\/strong><\/p>\n\n\n\n
\u7ed3\u8bba: \u8bfb\u9501\u4e0d\u4f1a\u963b\u585e\u5176\u4ed6\u5ba2\u6237\u7aef\u7684\u8bfb\uff0c\u4f46\u662f\u4f1a\u963b\u585e\u5199\u3002\u5199\u9501\u65e2\u4f1a\u963b\u585e\u5176\u4ed6\u5ba2\u6237\u7aef\u7684\u8bfb\uff0c\u53c8\u4f1a\u963b\u585e<\/p>\n\n\n\n
\u5176\u4ed6\u5ba2\u6237\u7aef\u7684\u5199\u5165<\/p>\n\n\n\n
\u5143\u6570\u636e\u9501<\/strong><\/h3>\n\n\n\n
meta data lock , \u5143\u6570\u636e\u9501\uff0c\u7b80\u5199MDL\u3002<\/p>\n\n\n\n
MDL\u52a0\u9501\u8fc7\u7a0b\u662f\u7cfb\u7edf\u81ea\u52a8\u63a7\u5236\uff0c\u65e0\u9700\u663e\u5f0f\u4f7f\u7528\uff0c\u5728\u8bbf\u95ee\u4e00\u5f20\u8868\u7684\u65f6\u5019\u4f1a\u81ea\u52a8\u52a0\u4e0a\u3002MDL\u9501\u4e3b\u8981\u4f5c\u7528\u662f\u7ef4\u62a4\u8868\u5143\u6570\u636e\u7684\u6570\u636e\u4e00\u81f4\u6027\uff0c\u5728\u8868\u4e0a\u6709\u6d3b\u52a8\u4e8b\u52a1<\/strong>\u7684\u65f6\u5019\uff0c\u4e0d\u53ef\u4ee5\u5bf9\u5143\u6570\u636e\u8fdb\u884c\u5199\u5165\u64cd\u4f5c\uff0c\u6240\u4ee5\u5143\u6570\u636e\u9501\u4e00\u822c\u5b58\u5728\u4e8e\u4e8b\u7269\u4e2d\uff0c\u5f53\u4e8b\u7269\u5f00\u542f\u540e\uff0c\u5ba2\u6237\u7aef\u4e00\u6267\u884c\u4e86DML\u8bed\u53e5\uff0c\u5728\u4e8b\u7269\u6ca1\u7ed3\u675f\u524d\uff0c\u5ba2\u6237\u7aef\u4e8c\u65e0\u6cd5\u6267\u884cDDL\u8bed\u53e5\uff0c\u76f4\u5230\u4e8b\u7269\u7ed3\u675f\u3002\u4e3a\u4e86\u907f\u514dDML\u4e0eDDL\u51b2\u7a81\uff0c\u4fdd\u8bc1\u8bfb\u5199\u7684\u6b63\u786e\u6027\u3002<\/strong><\/p>\n\n\n\n
\u8fd9\u91cc\u7684\u5143\u6570\u636e\uff0c\u5927\u5bb6\u53ef\u4ee5\u7b80\u5355\u7406\u89e3\u4e3a\u5c31\u662f\u4e00\u5f20\u8868\u7684\u8868\u7ed3\u6784\u3002 \u4e5f\u5c31\u662f\u8bf4\uff0c\u67d0\u4e00\u5f20\u8868\u6d89\u53ca\u5230\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u65f6\uff0c\u662f\u4e0d\u80fd\u591f\u4fee\u6539\u8fd9\u5f20\u8868\u7684\u8868\u7ed3\u6784\u7684\u3002<\/p>\n\n\n\n
\u5728MySQL5.5\u4e2d\u5f15\u5165\u4e86MDL\uff0c\u5f53\u5bf9\u4e00\u5f20\u8868\u8fdb\u884c\u589e\u5220\u6539\u67e5\u7684\u65f6\u5019\uff0c\u52a0MDL\u8bfb\u9501(\u5171\u4eab)\uff1b\u5f53\u5bf9\u8868\u7ed3\u6784\u8fdb\u884c\u53d8\u66f4\u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u52a0MDL\u5199\u9501(\u6392\u4ed6)\u3002<\/p>\n\n\n\n
\u5e38\u89c1\u7684SQL\u64cd\u4f5c\u65f6\uff0c\u6240\u6dfb\u52a0\u7684\u5143\u6570\u636e\u9501\u6709<\/p>\n\n\n\n
\u5bf9\u5e94SQL<\/strong><\/td>\u9501\u7c7b\u578b<\/strong><\/td>\u8bf4\u660e<\/strong><\/td><\/tr>
lock tables xxx read \/
write<\/td>		SHARED_READ_ONLY \/
SHARED_NO_READ_WRITE
(shared_read_only\/shared_no_read_write)<\/td>		<\/td><\/tr>
select \u3001select …
lock in share mode<\/td>		SHARED_READ(shared_read)<\/td>\u4e0eSHARED_READ\u3001
SHARED_WRITE\u517c\u5bb9\uff0c\u4e0e
EXCLUSIVE\u4e92\u65a5<\/td><\/tr>
insert \u3001update\u3001
delete\u3001select … for
update<\/td>		SHARED_WRITE(shared_write)<\/td>\u4e0eSHARED_READ\u3001
SHARED_WRITE\u517c\u5bb9\uff0c\u4e0e
EXCLUSIVE\u4e92\u65a5<\/td><\/tr>
alter table …<\/td>EXCLUSIVE(exclusive)<\/td>\u4e0e\u5176\u4ed6\u7684MDL\u90fd\u4e92\u65a5<\/td><\/tr><\/tbody><\/table>
shared_read\u4e0eshared_write \u76f8\u4e92\u517c\u5bb9\uff0c\u800cshared_write\u548cshared_read \u4e0eexclusive \u76f8\u4e92\u6392\u65a5\uff0c\u524d\u63d0\u662f\u9700\u4f5c\u7528\u4e8e\u540c\u4e00\u5f20\u8868<\/figcaption><\/figure>\n\n\n\n
\u6f14\u793a<\/strong><\/p>\n\n\n\n
\u5f53\u6267\u884cSELECT\u3001INSERT\u3001UPDATE\u3001DELETE\u7b49\u8bed\u53e5\u65f6\uff0c\u6dfb\u52a0\u7684\u662f\u5143\u6570\u636e\u5171\u4eab\u9501\uff08SHARED_READ \/<\/p>\n\n\n\n
SHARED_WRITE\uff09\uff0c\u4e4b\u95f4\u662f\u517c\u5bb9\u7684<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u5f53\u6267\u884cSELECT\u8bed\u53e5\u65f6\uff0c\u6dfb\u52a0\u7684\u662f\u5143\u6570\u636e\u5171\u4eab\u9501\uff08SHARED_READ\uff09\uff0c\u4f1a\u963b\u585e\u5143\u6570\u636e\u6392\u4ed6\u9501<\/p>\n\n\n\n
\uff08EXCLUSIVE\uff09\uff0c\u4e4b\u95f4\u662f\u4e92\u65a5\u7684\uff0c\u9700\u8981\u7b49\u5230\u4e8b\u7269\u63d0\u4ea4\u540e\u624d\u4f1a\u6267\u884c<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u67e5\u770b\u6570\u636e\u5e93\u4e2d\u5143\u6570\u636e\u5e93\u60c5\u51b5<\/p>\n\n\n\n
select object_type,object_schema,object_name,lock_type,lock_duration from\nperformance_schema.metadata_locks ;<\/code><\/pre>\n\n\n\n
\u610f\u5411\u9501<\/strong><\/h3>\n\n\n\n
\u4ecb\u7ecd<\/p>\n\n\n\n
\u4e3a\u4e86\u907f\u514dDML\u5728\u6267\u884c\u65f6\uff0c\u52a0\u7684\u884c\u9501\u4e0e\u8868\u9501\u7684\u51b2\u7a81\uff0c\u5728InnoDB\u4e2d\u5f15\u5165\u4e86\u610f\u5411\u9501\uff0c\u4f7f\u5f97\u8868\u9501\u4e0d\u7528\u68c0\u67e5\u6bcf\u884c\u6570\u636e\u662f\u5426\u52a0\u9501\uff0c\u4f7f\u7528\u610f\u5411\u9501\u6765\u51cf\u5c11\u8868\u9501\u7684\u68c0\u67e5<\/p>\n\n\n\n
\u5047\u5982\u6ca1\u6709\u610f\u5411\u9501\uff0c\u5ba2\u6237\u7aef\u4e00\u5bf9\u8868\u52a0\u4e86\u884c\u9501\u540e\uff0c\u5ba2\u6237\u7aef\u4e8c\u5982\u4f55\u7ed9\u8868\u52a0\u8868\u9501\u5462\uff1f<\/p>\n\n\n\n
\u9996\u5148\u5ba2\u6237\u7aef\u4e00\uff0c\u5f00\u542f\u4e00\u4e2a\u4e8b\u52a1\uff0c\u7136\u540e\u6267\u884cDML\u64cd\u4f5c\uff0c\u5728\u6267\u884cDML\u8bed\u53e5\u65f6\uff0c\u4f1a\u5bf9\u6d89\u53ca\u5230\u7684\u884c\u52a0\u884c\u9501\u3002\u5f53\u5ba2\u6237\u7aef\u4e8c\uff0c\u60f3\u5bf9\u8fd9\u5f20\u8868\u52a0\u8868\u9501\u65f6\uff0c\u4f1a\u68c0\u67e5\u5f53\u524d\u8868\u662f\u5426\u6709\u5bf9\u5e94\u7684\u884c\u9501\uff0c\u5982\u679c\u6ca1\u6709\uff0c\u5219\u6dfb\u52a0\u8868\u9501\uff0c\u6b64\u65f6\u5c31\u4f1a\u4ece\u7b2c\u4e00\u884c\u6570\u636e\uff0c\u68c0\u67e5\u5230\u6700\u540e\u4e00\u884c\u6570\u636e\uff0c\u6548\u7387\u8f83\u4f4e\u3002<\/p>\n\n\n\n
\u6709\u4e86\u610f\u5411\u9501\u4e4b\u540e :<\/p>\n\n\n\n
\u5ba2\u6237\u7aef\u4e00\uff0c\u5728\u6267\u884cDML\u64cd\u4f5c\u65f6\uff0c\u4f1a\u5bf9\u6d89\u53ca\u7684\u884c\u52a0\u884c\u9501\uff0c\u540c\u65f6\u4e5f\u4f1a\u5bf9\u8be5\u8868\u52a0\u4e0a\u610f\u5411\u9501\u3002\u800c\u5176\u4ed6\u5ba2\u6237\u7aef\uff0c\u5728\u5bf9\u8fd9\u5f20\u8868\u52a0\u8868\u9501\u7684\u65f6\u5019\uff0c\u4f1a\u6839\u636e\u8be5\u8868\u4e0a\u6240\u52a0\u7684\u610f\u5411\u9501\u6765\u5224\u5b9a\u662f\u5426\u53ef\u4ee5\u6210\u529f\u52a0\u8868\u9501\uff0c\u800c\u4e0d\u7528\u9010\u884c\u5224\u65ad\u884c\u9501\u60c5\u51b5\u4e86\u3002<\/p>\n\n\n\n
\u5206\u7c7b<\/strong><\/h4>\n\n\n\n
\u610f\u5411\u5171\u4eab\u9501(IS): \u7531\u8bed\u53e5select … lock in share mode\u6dfb\u52a0 \u3002 \u4e0e \u8868\u9501\u5171\u4eab\u9501(read)\u517c\u5bb9\uff0c\u4e0e\u8868\u9501\u6392\u4ed6\u9501(write)\u4e92\u65a5\u3002<\/p>\n\n\n\n
\u610f\u5411\u6392\u4ed6\u9501(IX): \u7531insert\u3001update\u3001delete\u3001select…for update\u6dfb\u52a0 \u3002\u4e0e\u8868\u9501\u5171\u4eab\u9501(read)\u53ca\u6392\u4ed6\u9501(write)\u90fd\u4e92\u65a5\uff0c\u610f\u5411\u9501\u4e4b\u95f4\u4e0d\u4f1a\u4e92\u65a5\u3002\u7531DML\u8bed\u53e5\u5373\u53ef\uff0c\u4e0d\u9700\u8981for update<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u4e00\u65e6\u4e8b\u52a1\u63d0\u4ea4\u4e86\uff0c\u610f\u5411\u5171\u4eab\u9501\u3001\u610f\u5411\u6392\u4ed6\u9501\uff0c\u90fd\u4f1a\u81ea\u52a8\u91ca\u653e<\/strong><\/p>\n\n\n\n
\u901a\u8fc7\u4ee5\u4e0bSQL\uff0c\u67e5\u770b\u610f\u5411\u9501\u53ca\u884c\u9501\u7684\u52a0\u9501\u60c5\u51b5<\/p>\n\n\n\n
select object_schema,object_name,index_name,lock_type,lock_mode,lock_data from\nperformance_schema.data_locks;<\/code><\/pre>\n\n\n\n
\u6f14\u793a<\/strong><\/h4>\n\n\n\n
\u610f\u5411\u5171\u4eab\u9501\u4e0e\u8868\u8bfb\u9501\u662f\u517c\u5bb9\u7684<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u610f\u5411\u6392\u4ed6\u9501\u4e0e\u8868\u8bfb\u9501\u3001\u5199\u9501\u90fd\u662f\u4e92\u65a5\u7684<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u9762\u8bd5\u9898<\/strong><\/h2>\n\n\n\n
\u6570\u636e\u5e93\u7d22\u5f15\u7684\u5e95\u5c42\u6570\u636e\u7ed3\u6784<\/strong>
\u4e8c\u53c9\u6811\u5728\u67d0\u4e9b\u573a\u666f\u4e0b\u4f1a\u9000\u5316\u6210\u94fe\u8868\u800c\u94fe\u8868\u7684\u67e5\u627e\u9700\u8981\u4ece\u5934\u90e8\u5f00\u59cb\u904d\u5386\uff0c\u800c\u8fd9\u5c31\u5931\u53bb\u4e86\u52a0\u7d22\u5f15\u7684\u610f\u4e49\u3002\u4e0d\u4f7f\u7528\u7ea2\u9ed1\u6811\u7684\u539f\u56e0\u662f:\u7ea2\u9ed1\u6811\u8fd8\u662f\u4e8c\u53c9\u6811\uff0c\u5728\u9762\u5bf9\u8868\u6570\u636e\u6570\u767e\u4e07\u6570\u5343\u4e07\u7684\u573a\u666f\u65f6\uff0c\u4f1a\u5bfc\u81f4\u7d22\u5f15\u6811\u7684\u5c42\u6570\u5f88\u9ad8\u5bfc\u81f4\u67e5\u8be2\u6548\u7387\u4f4e\uff0c\u800c B+\u6811\u7531 B \u6811\u548c\u7d22\u5f15\u987a\u5e8f\u8bbf\u95ee\u65b9\u6cd5\u6f14\u5316\u800c\u6765\uff0c\u5b83\u662f\u4e3a\u78c1\u76d8\u8bbe\u8ba1\u7684\u4e00\u79cd\u5e73\u8861\u67e5\u627e\u6811\uff0c\u5728 B+\u6811\u4e2d,\u6240\u6709\u8bb0\u5f55\u8282\u70b9\u90fd\u662f\u6309\u952e\u503c\u7684\u5927\u5c0f\u987a\u5e8f\u5b58\u653e\u5728\u540c\u4e00\u5c42\u7684\u53f6\u5b50\u8282\u70b9\uff0c\u5404\u53f6\u5b50\u8282\u70b9\u901a\u8fc7\u5355\u5411\u6307\u9488\u8fdb\u884c\u8fde\u63a5\u3002B+\u6811\u7d22\u5f15\u5728\u6570\u636e\u5e93\u4e2d\u7684\u4e00\u4e2a\u7279\u70b9\u5c31\u662f\u9ad8\u6247\u51fa\u6027\uff0c\u4f8b\u5982\u5728lnnoDB \u5b58\u50a8\u5f15\u64ce\u4e2d\uff0c\u6bcf\u4e2a\u9875\u7684\u5927\u5c0f\u4e3a 16KB\u3002\u6570\u636e\u5e93\u4e2d\uff0cB+\u6811\u7684\u9ad8\u5ea6\u4e00\u822c\u90fd\u5728 2~4 \u5c42\uff0c\u8fd9\u610f\u5473\u7740\u67e5\u627e\u67d0\u4e00\u952e\u503c\u6700\u591a\u53ea\u9700\u8981 2 \u5230 4 \u6b210 \u64cd\u4f5c\uff0c\u56e0\u4e3a\u73b0
\u5728\u4e00\u822c\u7684\u78c1\u76d8\u6bcf\u79d2\u81f3\u5c11\u53ef\u4ee5\u505a100\u6b21I0\u64cd\u4f5c,2~4\u6b21\u76840\u64cd\u4f5c\u610f\u5473\u7740\u67e5\u8be2\u65f6\u95f4\u53ea\u97000.02~0.04\u79d2<\/p>\n\n\n\n
<\/p>\n\n\n\n

B \u6811\u548c B+\u6811\u7684\u533a\u522b<\/strong>
\u5b83\u4eec\u90fd\u662f\u5e73\u8861\u591a\u8def\u67e5\u627e\u6811\uff0c\u662f\u5728\u4e8c\u53c9\u67e5\u627e\u6811\u57fa\u7840\u4e0a\u7684\u6539\u8fdb\u6570\u636e\u7ed3\u6784\u3002b+\u6811\u6570\u636e\u5b58\u653e\u5728\u53f6\u5b50\u7ed3\u70b9\u4e0a\uff0c\u975e\u53f6\u5b50\u7ed3\u70b9\u53ea\u5b58 key\uff0c\u800c b \u6811\u6570\u636e\u5b58\u653e\u5728\u53f6\u5b50\u7ed3\u70b9\u548c\u975e\u53f6\u5b50\u4e0a\uff0c\u6240\u4ee5\u76f8\u5bf9 b+\u6811\u7684\u5c42\u7ea7\u8981\u591a\uff0cB+\u6811\u4e3a\u6240\u6709\u53f6\u5b50\u8282\u70b9\u589e\u52a0\u4e86\u94fe\u63a5\uff0c\u4ece\u800c\u5b9e\u73b0\u4e86\u5feb\u901f\u7684\u8303\u56f4\u67e5\u627e<\/p>\n\n\n\n

\u6570\u636e\u5e93\u7684\u7d22\u5f15\u662f\u4ec0\u4e48\u7ed3\u6784\u4e3a\u4ec0\u4e48\u4e0d\u7528\u54c8\u5e0c\u8868<\/strong>
MySQL\u4e2d\u7684\u7d22\u5f15B+\u6811\u5b9e\u73b0\u7684:<\/p>\n\n\n\n
\u54c8\u5e0c\u8868\u8981\u6c42\u5c06\u6240\u6709\u6570\u636e\u8f7d\u5165\u5185\u5b58\uff0c\u800c\u6570\u636e\u5e93\u5b58\u50a8\u7684\u6570\u636e\u91cf\u7ea7\u53ef\u80fd\u4f1a\u975e\u5e38\u5927\uff0c\u5168\u90e8\u8f7d\u5165\u5185\u5b58\u57fa\u672c\u4e0a\u662f\u4e0d\u53ef\u80fd\u5b9e\u73b0\u7684:B+\u6811\u53ef\u4ee5\u5206\u6bb5\u52a0\u8f7d\u9700\u8981\u7684\u8282\u70b9\u6570\u636e\uff0c\u53ef\u4ee5\u5728\u5185\u5b58\u8d44\u6e90\u6709\u9650\u7684\u524d\u63d0\u4e0b\uff0c\u6781\u5927\u63d0\u9ad8\u67e5\u8be2\u6548\u7387<\/p>\n\n\n\n
<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u8bf4\u8bf4MySQL \u7d22\u5f15\uff0c\u4ee5\u53ca\u5b83\u4eec\u7684\u597d\u5904\u548c\u574f\u5904<\/strong><\/p>\n\n\n\n
MvSQL\u7d22\u5f15\u662f\u4e00\u79cd\u5e2e\u52a9\u5feb\u901f\u67e5\u627e\u6570\u636e\u7684\u6570\u636e\u7ed3\u6784\uff0c\u4e3b\u8981\u6709\u666e\u901a\u7d22\u5f15\u3001\u552f\u4e00\u7d22\u5f15 (\u7d22\u5f15\u5217\u5fc5\u987b\u552f\u4e00\uff0c\u4f46\u5141\u8bb8\u6709\u7a7a\u503c\uff0c\u5982\u679c\u662f\u7ec4\u5408\u7d22\u5f15\uff0c\u90a3\u4e48\u7ec4\u5408\u7684\u5217\u5fc5\u987b\u552f\u4e00)\u3001\u4e3b\u952e\u7d22\u5f15(\u4e0d\u5141\u8bb8\u6709\u7a7a\u503c\uff0c\u4e00\u822c\u7528primary key\u7ea6\u675f)\u3001\u5916\u952e\u7d22\u5f15\u3001\u5168\u6587\u7d22\u5f15\u3001\u590d\u5408\u7d22\u5f15\u51e0\u79cd\u3002
\u5408\u7406\u4f7f\u7528\u7d22\u5f15\u80fd\u5927\u5e45\u63d0\u9ad8\u5339\u914d where \u6761\u4ef6\u7684\u68c0\u7d22\u6548\u7387\uff0c\u8fd8\u80fd\u7528\u4e8e\u6392\u5e8f\u3001\u5206\u7ec4\u3001\u8868\u4e0e\u8868\u8fde\u63a5\u7684\u52a0\u901f\u3002\u7d22\u5f15\u5fc5\u5b9a\u4f1a\u589e\u52a0\u5b58\u50a8\u8d44\u6e90\u7684\u6d88\u8017\uff0c\u540c\u65f6\u4e5f\u589e\u5927\u4e86\u63d2\u5165\u3001\u66f4\u65b0\u548c\u5220\u9664\u64cd\u4f5c\u7684\u7ef4\u62a4\u6210\u672c\uff0c\u56e0\u4e3a\u6bcf\u4e2a\u589e\u5220\u6539\u64cd\u4f5c\u540e\u76f8\u5e94\u5217\u7684\u7d22\u5f15\u90fd\u5fc5\u987b\u88ab\u66f4\u65b0\u3002<\/p>\n\n\n\n
\u53ea\u8981\u521b\u5efa\u4e86\u7d22\u5f15\uff0c\u5c31-\u5b9a\u4f1a\u8d70\u7d22\u5f15\u5417?
\u4e0d\u4e00\u5b9a\uff0c\u7ec4\u5408\u7d22\u5f15\u8981\u6309\u6700\u5de6\u524d\u7f00\u6cd5\u5219\uff0c\u5426\u5219\u5c06\u4e0d\u4f1a\u8d70\u8be5\u7d22\u5f15\u3002<\/p>\n\n\n\n
<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u7d22\u5f15\u7684\u8bbe\u8ba1\u539f\u5219<\/strong><\/p>\n\n\n\n
\u9002\u5408\u521b\u5efa\u7d22\u5f15\u7684\u60c5\u51b5:\u5bf9\u67e5\u8be2\u9891\u6b21\u8f83\u9ad8\u4e14\u6570\u636e\u91cf\u6bd4\u8f83\u5927\u7684\u8868\uff0c\u9891\u7e41\u51fa\u73b0\u5728where \u5b57\u53e5\u4e2d\u7684\u5217:\u4f7f\u7528\u552f\u4e00\u7d22\u5f15\uff0c\u533a\u5206\u5ea6\u8d8a\u9ad8\uff0c\u4f7f\u7528\u7d22\u5f15\u7684\u6548\u7387\u8d8a\u9ad8:\u8868\u4e0e\u8868\u8fde\u63a5\u7528\u4e8e\u591a\u8868\u67e5\u8be2\u7684\u7ea6\u675f\u6761\u4ef6\uff0c\u67e5\u8be2\u4e2d\u6392\u5e8f\u3001\u7edf\u8ba1\u3001\u5206\u7ec4\u7684\u5b57\u6bb5\uff0c\u9700\u8981\u6839\u636e\u8303\u56f4\u641c\u7d22\u7684\u5217\u3002\u4e0d\u9002\u5408\u521b\u5efa\u7d22\u5f15\u7684\u60c5\u51b5:\u57fa\u6570\u8f83\u5c0f\u7684\u8868\uff0c\u6ca1\u5fc5\u8981\u521b\u5efa\u7d22\u5f15;\u7ecf\u5e38\u589e\u5220\u6539\u7684\u8868\u4e0d\u9002\u5408\u521b\u5efa\u7d22\u5f15;\u66f4\u65b0\u9891\u7e41\u7684\u5b57\u6bb5\u4e0d\u8981\u6709\u7d22\u5f15;\u5b57\u6bb5\u503c\u552f\u4e00\u6027\u4e0d\u9ad8\u7684\u5b57\u6bb5\uff0c\u5982\u6027\u522b\u3001\u5a5a\u59fb\u60c5\u51b5;\u5b9a\u4e49\u4e3atext\u548c bit \u6570\u636e\u7c7b\u578b\u7684\u5217\u4e0d\u9002\u5408\u521b\u5efa\u7d22\u5f15\uff0c\u56e0\u4e3a\u8fd9\u4e9b\u5217\u7684\u6570\u636e\u8981\u4e48\u5f88\u5927\u8981\u4e48\u5f88\u5c0f,\u5f88\u5c11\u4f7f\u7528\u7684\u5217\u4e0d\u9700\u7537\u521b\u5efa\u7d22\u5f00<\/p>\n\n\n\n
<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u7d22\u5f15\u5931\u6548<\/strong><\/p>\n\n\n\n
\u53f3\u8fb9\u7684\u5217\u4e0d\u80fd\u4f7f\u7528\u7d22\u5f15\uff0c\u5426\u5219\u53f3\u8fb9\u7684\u7d22\u5f15\u4e3a\u5931\u6548\uff0c\u5982:\u5927\u4e8e\u5c0f\u4e8e\u4ee5\u53ca\u8303\u56f4\u67e5\u627ebetween\u5728\u7d22\u5f15\u4e0a\u4f7f\u7528\u8fd0\u7b97\u51fd\u6570\u4f1a\u5bfc\u81f4\u7d22\u5f15\u5931\u6548,\u5982avg\u3001sum\u3001count\u3001max\u3001min\u3001substring\u7b49\u3002
\u4f7f\u7528\u590d\u5408\u7d22\u5f15\uff0c\u8981\u9075\u5faa\u6700\u5de6\u524d\u7f00\u6cd5\u5219\uff0c\u67e5\u8be2\u4ece\u7d22\u5f15\u7684\u6700\u5de6\u5217\u5f00\u59cb\uff0c\u4e0d\u80fd\u8df3\u8fc7\u7d22\u5f15\u4e2d\u95f4\u5217\u4e0d\u8981\u5728where\u5b50\u53e5\u4e2d\u5bf9\u5b57\u6bb5\u8fdb\u884c null \u503c\u5224\u65ad\u548c\u6a21\u7cca\u67e5\u8be2\u4ee5\u53ca\u4f7f\u7528!=\u6216<>\u64cd\u4f5c\u7b26
\u5982\u679c\u7d22\u5f15\u5217\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\u7684\u6574\u6570\uff0c\u6761\u4ef6\u67e5\u8be2\u7684\u65f6\u5019\u4e0d\u52a0\u5f15\u53f7\u4f1a\u9020\u6210\u7d22\u5f15\u5931\u6548\u3002
\u5982\u679c\u7d22\u5f15\u5217\u5b8c\u5168\u5305\u542b\u67e5\u8be2\u5217\uff0c\u90a3\u4e48\u67e5\u8be2\u7684\u65f6\u5019\u628a\u8981\u67e5\u7684\u5217\u5199\u51fa\u6765\uff0c\u4e0d\u8981\u4f7f\u7528 select*
\u7528or \u5206\u5272\u5f00\u7684\u6761\u4ef6\uff0c\u5982\u679cor\u524d\u9762\u7684\u5217\u6709\u7d22\u5f15\uff0cor \u540e\u9762\u7684\u5217\u6ca1\u6709\u7d22\u5f15\uff0c\u90a3\u4e48\u67e5\u8be2\u7684\u65f6\u5019\u524d\u540e\u7d22\u5f15\u90fd\u4f1a\u5931\u6548\uff0c\u5e94\u8be5\u7528or \u8fde\u63a5\u7684\u5b57\u6bb5\u90fd\u52a0\u4e0a\u7d22\u5f15\u624d\u80fd\u751f\u6548<\/p>\n\n\n\n
<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u805a\u7c07\u7d22\u5f15\u548c\u975e\u805a\u7c07\u7d22\u5f15(\u805a\u5408\u7d22\u5f15\u548c\u4e8c\u7ea7\u7d22\u5f15)<\/strong><\/p>\n\n\n\n
\u805a\u7c07\u7d22\u5f15\u662f\u5c06\u6570\u636e\u4e0e\u7d22\u5f15\u5b58\u50a8\u5230\u4e00\u8d77\uff0c\u627e\u5230\u7d22\u5f15\u4e5f\u5c31\u627e\u5230\u4e86\u6570\u636e\uff0c\u800c\u975e\u805a\u7c07\u7d22\u5f15\u662f\u5c06\u6570
\u636e\u548c\u7d22\u5f15\u5b58\u50a8\u5206\u79bb\u5f00\uff0c\u7d22\u5f15\u6811\u7684\u53f6\u5b50\u8282\u70b9\u5b58\u50a8\u4e86\u6570\u636e\u884c\u7684\u5730\u5740\u3002
\u5728InnoDB \u5b58\u50a8\u5f15\u64ce\u4e2d\uff0c\u53ef\u4ee5\u5c06 B+\u6811\u7d22\u5f15\u5206\u4e3a\u805a\u7c07\u7d22\u5f15\u548c\u975e\u805a\u7c07\u7d22\u5f15\u3002\u65e0\u8bba\u662f\u4f55\u79cd\u7d22\u5f15\uff0c\u6bcf\u4e2a\u9875\u7684\u5927\u5c0f\u90fd\u4e3a16KB\u4e14\u4e0d\u80fd\u66f4\u6539\u3002\u805a\u7c07\u7d22\u5f15\u662f\u6839\u636e\u4e3b\u952e\u521b\u5efa\u7684\u4e00\u68f5 B+\u6811\uff0c\u805a\u7c07\u7d22\u5f15\u7684\u53f6\u5b50\u8282\u70b9\u5b58\u653e\u4e86\u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\u3002\u975e\u805a\u7c07\u7d22\u5f15\u662f\u6839\u636e\u7d22\u5f15\u952e\u521b\u5efa\u7684\u4e00\u68f5 B+\u6811<\/p>\n\n\n\n
\u4e0e\u805a\u7c07\u7d22\u5f15\u4e0d\u540c\u7684\u662f\uff0c\u5176\u53f6\u5b50\u8282\u70b9\u4ec5\u5b58\u653e\u7d22\u5f15\u952e\u503c\uff0c\u4ee5\u53ca\u8be5\u7d22\u5f15\u952e\u503c\u6307\u5411\u7684\u4e3b\u952e\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u901a\u8fc7\u975e\u805a\u7bf1\u7d22\u5f15\u6765\u67e5\u627e\u6570\u636e\uff0c\u90a3\u4e48\u5f53\u627e\u5230\u975e\u805a\u7c07\u7d22\u5f15\u7684\u53f6\u5b50\u8282\u70b9\u540e\uff0c\u5f88\u6709\u53ef\u80fd\u8fd8\u9700\u8981\u6839\u636e\u4e3b\u952e\u503c\u67e5\u627e\u805a\u7c07\u7d22\u5f15\u6765\u5f97\u5230\u6570\u636e\uff0c\u8fd9\u79cd\u67e5\u627e\u4e07\u5f0f\u53c8\u88ab\u79f0\u4e3a\u4e66\u7b7e\u67e5\u627e(\u56de\u8868\u67e5\u8be2)<\/p>\n\n\n\n
<\/p>\n\n\n\n
<\/p>\n\n\n\n
\u6570\u636e\u5e93\u5f15\u64ce\u6709\u54ea\u4e9b\u5404\u81ea\u6709\u4ec0\u4e48\u533a\u522b<\/strong><\/p>\n\n\n\n

InnoDB\u5f15\u64ce\u662fMySQL\u7684\u4e8b\u52a1\u5b89\u5168\u5b58\u50a8\u5f15\u64ce\uff0c\u5177\u6709\u63d0\u4ea4\u3001\u56de\u6eda\u548c\u5d29\u6e83\u6062\u590d\u529f\u80fd\u6765\u4fdd\u62a4\u7528\u6237\u6570\u636e\u3002
MvISAM\u5f15\u64ce\u7684\u8868\u5360\u7528\u7a7a\u95f4\u8f83\u5c0f\uff0c\u8868\u7ea7\u9501\u9650\u5236\u4e86\u8bfb\u5199\u5de5\u4f5c\u8d1f\u8f7d\u7684\u6027\u80fd\uff0c\u56e0\u6b64\u5b83\u901a\u5e38\u7528\u4e8e\u53ea\u8bfb\u6216\u4ee5\u8bfb\u53d6\u4e3a\u4e3b\u7684\u573a\u666f\u3002
Memory\u5f15\u64ce\u662f\u5c06\u6240\u6709\u6570\u636e\u5b58\u50a8\u5728\u5185\u5b58\u4e2d\uff0c\u4ee5\u4fbf\u5728\u9700\u8981\u5feb\u901f\u67e5\u627e\u975e\u5173\u952e\u6570\u636e\u7684\u73af\u5883\u4e2d\u8fdb\u884c\u5feb\u901f\u8bbf\u95ee\uff0c\u652f\u6301 hash \u7d22\u5f15\u3002
Archive\u5f15\u64ce\u975e\u5e38\u9002\u5408\u5b58\u50a8\u5927\u91cf\u7684\u72ec\u7acb\u7684\uff0c\u4f5c\u4e3a\u5386\u53f2\u8bb0\u5f55\u7684\u6570\u636e\uff0c\u56e0\u4e3a\u5b83\u4eec\u4e0d\u7ecf\u5e38\u88ab\u8bfb\u53d6\u3002\u5b83\u62e5\u6709\u9ad8\u6548\u7684\u63d2\u5165\u901f\u5ea6\uff0c\u4f46\u5176\u5bf9\u67e5\u8be2\u7684\u652f\u6301\u76f8\u5bf9\u8f83\u5dee
Cluster\/NDB\u662f\u9ad8\u4f59\u7684\u5b58\u50a8\u5f15\u64ce\uff0c\u7528\u591a\u53f0\u6570\u636e\u673a\u5668\u8054\u5408\u63d0\u4f9b\u670d\u52a1\u4ee5\u63d0\u9ad8\u6574\u4f53\u6027\u80fd\u548c\u5b89\u5168\u6027\u3002\u9002\u5408\u6570\u636e\u91cf\u5927\uff0c\u5b89\u5168\u548c\u6027\u80fd\u8981\u6c42\u9ad8\u7684\u5e94\u7528\u3002
Federated\u5f15\u64ce\u63d0\u4f9b\u8fde\u63a5\u5355\u72ec\u7684 mySQl\u670d\u52a1\u5668\u4ece\u591a\u4e2a\u7269\u670d\u52a1\u5668\u521b\u5efa\u4e00\u4e2a\u903b\u8f91\u6570\u636e\u5e93\u7684\u80fd\u529b\uff0c\u975e\u5e38\u9002\u5408\u5206\u5e03\u5f0f\u6216\u6570\u636e\u96c6\u5e02\u73af\u5883\u3002<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5b58\u50a8\u5f15\u64ce \u89e3\u91ca \u5b58\u50a8\u5f15\u64ce\u5c42\uff0c \u5b58\u50a8\u5f15\u64ce\u771f\u6b63\u7684\u8d1f\u8d23\u4e86MySQL\u4e2d\u6570\u636e\u7684\u5b58\u50a8\u548c\u63d0\u53d6\uff0c\u670d\u52a1\u5668\u901a\u8fc7API\u548c\u5b58\u50a8\u5f15\u64ce\u8fdb\u884c […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,9],"tags":[29,39],"class_list":["post-1831","post","type-post","status-publish","format-standard","hentry","category-mysql","category-9","tag-mysql","tag-39"],"_links":{"self":[{"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/posts\/1831","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=1831"}],"version-history":[{"count":0,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=\/wp\/v2\/posts\/1831\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1831"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1831"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.chencuo.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1831"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}