{"id":326,"date":"2023-05-28T01:47:22","date_gmt":"2023-05-27T17:47:22","guid":{"rendered":"https:\/\/xinchewhd.com.cn\/?p=326"},"modified":"2023-05-28T01:47:23","modified_gmt":"2023-05-27T17:47:23","slug":"45%e4%b8%aa%e6%95%b0%e6%8d%ae%e5%ba%93sql%e6%80%a7%e8%83%bd%e4%bc%98%e5%8c%96%e6%96%b9%e6%a1%88%ef%bc%8csql%e6%80%a7%e8%83%bd%e6%8f%90%e5%8d%87%e5%a5%bd%e5%87%a0%e5%80%8d%ef%bc%81","status":"publish","type":"post","link":"https:\/\/xinchewhd.com.cn\/index.php\/mysql\/45%e4%b8%aa%e6%95%b0%e6%8d%ae%e5%ba%93sql%e6%80%a7%e8%83%bd%e4%bc%98%e5%8c%96%e6%96%b9%e6%a1%88%ef%bc%8csql%e6%80%a7%e8%83%bd%e6%8f%90%e5%8d%87%e5%a5%bd%e5%87%a0%e5%80%8d%ef%bc%81\/","title":{"rendered":"45\u4e2a\u6570\u636e\u5e93SQL\u6027\u80fd\u4f18\u5316\u65b9\u6848\uff0cSQL\u6027\u80fd\u63d0\u5347\u597d\u51e0\u500d\uff01"},"content":{"rendered":"
\n

1 MySQL\u7684\u6267\u884c\u6d41\u7a0b<\/h1>\n

\u4e3a\u4e86\u66f4\u597d\u7684\u53d6\u4f18\u5316SQL\uff0c\u8fd9\u91cc\u5148\u603b\u7ed3\u4e86\u4e00\u4e0bSQL\u6267\u884c\u6d41\u7a0b\uff1a<\/p>\n

1<\/span>\u3001\u5ba2\u6237\u7aef\u8bf7\u6c42\u5230\u670d\u52a1\u7aef\uff0c\u670d\u52a1\u7aef\u901a\u8fc7\u6570\u636e\u5e93\u8fde\u63a5\u6c60\uff0c\u7528JDBC\u8fde\u63a5\u6570\u636e\u5e93\u9a71\u52a8\u3002<\/span>\n2<\/span>\u3001\u6570\u636e\u5e93\u7aef\u7684\u8fde\u63a5\u6c60\u63a5\u6536\u5230\u670d\u52a1\u7aef\u7684\u8fde\u63a5\uff0c\u7136\u540e\u628a\u670d\u52a1\u7aef\u5bf9\u6570\u636e\u5e93\u7684\u8bf7\u6c42\u4ea4\u7ed9\u6570\u636e\u5e93\u7684\u7ebf\u7a0b\u3002<\/span>\n3<\/span>\u3001\u901a\u8fc7\u6570\u636e\u5e93\u83b7\u53d6SQL\u63a5\u53e3\uff0c\u83b7\u53d6\u5230\u8fde\u63a5\u4e2d\u7684SQL\u8bed\u53e5\u3002<\/span>\n4<\/span>\u3001\u7136\u540e\u662f\u901a\u8fc7\u6570\u636e\u5e93\u89e3\u6790\u5668\u5bf9SQL\u8fdb\u884c\u89e3\u6790\uff08\u89e3\u6790\u6210\u6570\u636e\u5e93\u8ba4\u8bc6\u7684\u8bed\u8a00\uff09\u3002<\/span>\n5<\/span>\u3001\u7136\u540e\u901a\u8fc7SQL\u67e5\u8be2\u4f18\u5316\u5668\u83b7\u5f97\u6700\u4f18\u6267\u884cSQL\u3002<\/span>\n6<\/span>\u3001\u6700\u7ec8\u628a\u6700\u4f18SQL\u4ea4\u7ed9\u6570\u636e\u5e93\u6267\u884c\u5668\u3002<\/span>\n7<\/span>\u3001\u6267\u884c\u5668\u9009\u62e9\u5f53\u524d\u6570\u636e\u5e93\u7684\u5b58\u50a8\u5f15\u64ce\uff08\u56fe\u4f8b\u91c7\u7528InnoDB\u4e3a\u4f8b\uff09\u3002<\/span>\n8<\/span>\u3001\u7136\u540e\u5148\u53bb\u6570\u636e\u5e93\u7684BufferPool\uff08\u7f13\u5b58\uff09\u4e2d\u67e5\u8be2\uff0c\u8fd9\u91cc\u5982\u679c\u547d\u4e2d\u4e86\u7f13\u5b58\u5219\u76f4\u63a5\u8fd4\u56de\u7ed3\u679c\u3002<\/span>\n9<\/span>\u3001\u5982\u679c\u6ca1\u6709\u5728\u7f13\u5b58\u4e2d\u547d\u4e2d\u7ed3\u679c\uff0c\u90a3\u4e48\u4f1a\u53bb\u786c\u76d8\u4e2d\u8bfb\u53d6\u6570\u636e\uff0c\u7136\u540e\u8fd4\u56de\u7ed3\u679c\u96c6\u5e76\u7f13\u5b58\u8d77\u6765\uff0c\u4ee5\u4fbf\u4e0b\u6b21\u53d6\u7528\u3002<\/span><\/code><\/pre>\n
SQL\u6267\u884c\u6d41\u7a0b\u56fe\uff1a<\/p>\n
\n
2 \u6570\u636e\u5e93\u4f7f\u7528\u89c4\u8303<\/h1>\n
\u5408\u7406\u4f7f\u7528\u6570\u636e\u5e93\u89c4\u8303\u4e5f\u662fSQL\u6027\u80fd\u4f18\u5316\u7684\u524d\u63d0\u3002<\/p>\n
1<\/span>\u3001\u8868\u547d\u540d\u5fc5\u987b\u5c0f\u5199\u5b57\u6bcd\u4e14\u4e0b\u5212\u7ebf\u5206\u5272\u5355\u8bcd\uff1b<\/span>\n2<\/span>\u3001\u8868\u540d\u79f0\u53ca\u5b57\u6bb5\u540d\u79f0\u4e0d\u8981\u7528\u6570\u636e\u5e93\u7684\u5173\u952e\u5b57\uff1b<\/span>\n3<\/span>\u3001\u6570\u636e\u5e93\u8868\u547d\u540d\u4e0d\u8d85\u8fc732\u4e2a\u5b57\u7b26\uff1b<\/span>\n4<\/span>\u3001\u9075\u5faa\u6570\u636e\u5e93\u4e09\u8303\u5f0f\uff1b<\/span>\n5<\/span>\u3001\u5408\u7406\u7684\u53cd\u4e09\u8303\u5f0f\u4f7f\u7528\uff08\u6bd4\u5982\u5408\u7406\u7684\u5197\u4f59\u5b57\u6bb5\u518d\u4e00\u5f20\u8868\uff09\uff1b<\/span><\/code><\/pre>\n
3 45\u4e2aSQL\u4f18\u5316\u65b9\u6848<\/h1>\n
    \n
  • \u6d89\u53ca\u5230\u94b1\u7684\u5b57\u6bb5\u7528decimal<\/span><\/span><\/li>\n<\/ul>\n
    \u975e\u7cbe\u51c6\u6d6e\u70b9\uff1afloat<\/span>,double\u3002\n\u7cbe\u51c6\u6d6e\u70b9\uff1adecimal\u3002\n\nDecimal\uff1a\n  1\u3001\u5e95\u5c42\u5b58\u50a8\u7684\u6570\u636e\u8f6c\u6210\u5b57\u7b26\u4e32\u5f62\u5f0f\u5b58\u50a8\uff0c\u56e0\u6b64\u80fd\u4fdd\u6301\u7cbe\u5ea6\uff1b\n  2\u3001\u53ef\u5b58\u6bd4bigint\u66f4\u5927\u7684\u6570\u636e\uff1b\n  3\u3001\u5728\u8ba1\u7b97\u65f6\u4e0d\u4f1a\u4e22\u5931\u7cbe\u5ea6\uff1b\n  4\u3001\u5360\u7528\u7a7a\u95f4\u7531\u5b9a\u4e49\u7684\u5bbd\u5ea6\u51b3\u5b9a\uff0c\u6bcf4\u4e2a\u5b57\u8282\u53ef\u4ee5\u5b58\u50a89\u4f4d\u6570\u5b57\uff0c\u5e76\u4e14\u5c0f\u6570\u70b9\u8981\u5360\u7528\u4e00\u4e2a\u5b57\u8282\uff1b<\/code><\/pre>\n
      \n
    • \u5c3d\u91cf\u4e0d\u7528ENUM\u7c7b\u578b<\/span><\/span><\/span><\/li>\n<\/ul>\n
      1\u3001\u7981\u6b62\u628a\u6570\u5b57\u4f5c\u4e3aENUM\u503c\uff1b\n2\u3001\u4fee\u6539ENUM\u503c\u9700\u7528ALTER<\/span>\u8bed\u53e5\uff1b\n3<\/span>\u3001ENUM\u7c7b\u578b\u4f7f\u7528ORDER<\/span> BY<\/span>\u6548\u7387\u6781\u4f4e\uff1b<\/code><\/pre>\n
        \n
      • \u907f\u514ddistinct\u8fc7\u6ee4\u5b57\u6bb5\u8fc7\u591a<\/span><\/span><\/span><\/li>\n<\/ul>\n
        1<\/span>\u3001distinct\u4f7f\u7528\u65f6CPU\u5360\u7528\u65f6\u95f4\u957f<\/span>\n2<\/span>\u3001\u5bf9\u91cd\u590d\u6570\u636e\u6bd4\u8f83\u3001\u8fc7\u6ee4\u7684\u8fc7\u7a0b\u4f1a\u5360\u7528\u7cfb\u7edf\u8d44\u6e90\uff0c\u5982cpu\u65f6\u95f4\u3002<\/span>\n3<\/span>\u3001\u67e5\u8be2\u8fd4\u56de\u5b57\u6bb5\u591a\u65f6\uff0c\u7528distinct\u6570\u636e\u5e93\u4f1a\u5bf9\u91cd\u590d\u6570\u636e\u8fdb\u884c\u8fc7\u6ee4\u3002<\/span><\/code><\/pre>\n
          \n
        • where\u540e\u9ed8\u8ba4\u503c\u66ff\u6362null<\/span><\/span><\/span><\/li>\n<\/ul>\n
          1<\/span>\u3001\u5982\u679c\u9ed8\u8ba4\u503c\u66ff\u6362null\uff0c\u5f80\u5f80\u53ef\u4ee5\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u3002<\/span>\n2<\/span>\u3001\u6570\u636e\u5e93\u4f18\u5316\u5668\u53d1\u73b0\uff0c\u8d70\u7d22\u5f15\u6bd4\u4e0d\u8d70\u7d22\u5f15\u6210\u672c\u8fd8\u8981\u9ad8\uff0c\u5c31\u4f1a\u653e\u5f03\u7d22\u5f15\uff0c\u8fd9\u4e9b\u6761\u4ef6<\/span> !=\uff0c<>\uff0cis<\/span> null<\/span>\uff0cis<\/span> not<\/span> null<\/span>\u7ecf\u5e38\u88ab\u8ba4\u4e3a\u8ba9\u7d22\u5f15\u5931\u6548\uff0c\u8fd9\u4e9b\u90fd\u662f\u4f18\u5316\u5668\u81ea\u52a8\u653e\u5f03\u7d22\u5f15\u7684\uff1b<\/span><\/code><\/pre>\n
            \n
          • where\u540e\u907f\u514d\u4f7f\u7528!=\u3001<><\/span><\/span><\/span><\/li>\n<\/ul>\n
            1\u3001!=\u3001<><\/span>\u53ef\u80fd\u4f1a\u8ba9\u7d22\u5f15\u5931\u6548\u3002\n2\u3001\u5728where\u540e\u7528!=\u3001<><\/span>\uff0c\u5f15\u64ce\u53ef\u80fd\u4f1a\u4e0d\u7528\u7d22\u5f15\u800c\u5168\u8868\u626b\u63cf\u3002<\/code><\/pre>\n
              \n
            • \u8fde\u63a5\u8868\uff0c\u4f18\u5148\u7528inner join<\/span><\/span><\/span><\/li>\n<\/ul>\n
              inner join \u3001left join\u548cright join\u4e09\u79cd\u8fde\u63a5\u8868\uff1a<\/p>\n
              1<\/span>\u3001inner join<\/span>\n\u5185\u8fde\u63a5\uff0c\u53ea\u4fdd\u7559\u4e24\u5f20\u8868\u4e2d\u5b8c\u5168\u5339\u914d\u7684\u7ed3\u679c\u96c6\uff1b\n\n2<\/span>\u3001left<\/span> join<\/span>\n\u4f1a\u8fd4\u56de\u5de6\u8868\u6240\u6709\u7684\u884c\uff0c\u5373\u4f7f\u5728\u53f3\u8868\u4e2d\u6ca1\u6709\u5339\u914d\u7684\u8bb0\u5f55\uff1b\n\n3<\/span>\u3001right<\/span> join<\/span>\n\u4f1a\u8fd4\u56de\u53f3\u8868\u6240\u6709\u7684\u884c\uff0c\u5373\u4f7f\u5728\u5de6\u8868\u4e2d\u6ca1\u6709\u5339\u914d\u7684\u8bb0\u5f55\uff1b<\/code><\/pre>\n
              1<\/span>\u3001\u7528left<\/span> join<\/span>\u5de6\u8868\u6570\u636e\u7ed3\u679c\u5c3d\u91cf\u5c0f\uff0c\u6761\u4ef6\u5c3d\u91cf\u653e\u5230\u5de6\u8fb9\u5904\u7406\uff1b\n2<\/span>\u3001\u5982\u679c\u8fd4\u56de\u7ed3\u679c\u76f8\u540c\uff0c\u4f18\u9009inner join<\/span>\uff1b\n3<\/span>\u3001\u5982\u679cinner join<\/span>\u662f\u7b49\u503c\u8fde\u63a5\uff0c\u8fd4\u56de\u7684\u884c\u6570\u6bd4\u8f83\u5c11\uff0c\u6027\u80fd\u76f8\u5bf9\u4f1a\u597d\u4e00\u70b9\uff1b<\/code><\/pre>\n
              \u6027\u80fd\u6700\u4f18\u539f\u5219\uff1a\u5c0f\u8868\u9a71\u52a8\u5927\u8868\uff0c\u5c0f\u7684\u6570\u636e\u96c6\u9a71\u52a8\u5927\u7684\u6570\u636e\u96c6\uff1b<\/span><\/p>\n
                \n
              • \u8868\u5fc5\u7528Innodb\u5b58\u50a8\u5f15\u64ce<\/span><\/span><\/span><\/li>\n<\/ul>\n
                \u6240\u6709\u8868\u5c3d\u91cf\u7528Innodb\u5b58\u50a8\u5f15\u64ce\u3002<\/p>\n
                1<\/span>\u3001Innodb<\/span> \u652f\u6301\u4e8b\u52a1\uff0c\u652f\u6301\u884c\u7ea7\u9501\uff0c\u66f4\u597d\u7684\u6062\u590d\u6027\uff0c\u9ad8\u5e76\u53d1\u4e0b\u6027\u80fd\u66f4\u597d\u3002<\/span>\n2<\/span>\u3001\u5f53Innodb\u65e0\u6cd5\u6ee1\u8db3\u7684\u529f\u80fd\uff08\u5982\u5217\u5b58\u50a8\uff0c\u5b58\u50a8\u7a7a\u95f4\u6570\u636e\u7b49\uff09\u624d\u4e0d\u4f7f\u7528Innodb\u3002<\/span>\n3<\/span>\u3001mysql5.5\u4e4b\u524d\u9ed8\u8ba4\u4f7f\u7528Myisam\uff0c5.6\u4ee5\u540e\u9ed8\u8ba4\u7684\u4e3aInnodb\u3002<\/span>\n<\/code><\/pre>\n
                  \n
                • Innodb\u8868\u5fc5\u6709\u4e3b\u952e<\/span><\/span><\/span><\/li>\n<\/ul>\n
                  Innodb\u662f\u4e00\u79cd\u7d22\u5f15\u7ec4\u7ec7\u8868\uff1a\u6570\u636e\u7684\u5b58\u50a8\u7684\u903b\u8f91\u987a\u5e8f\u548c\u7d22\u5f15\u7684\u987a\u5e8f\u662f\u76f8\u540c\u7684\u3002\u8868\u53ef\u4ee5\u6709\u591a\u4e2a\u7d22\u5f15\uff0c\u4f46\u662f\u5b58\u50a8\u987a\u5e8f\u53ea\u53ef\u4e00\u79cd\uff0c\u4e5f\u5c31\u662f\u4e3b\u952e\u53ea\u80fd\u6709\u4e00\u4e2a\u3002<\/p>\n
                  Innodb\u662f\u6309\u7167\u4e3b\u952e\u7d22\u5f15\u7684\u987a\u5e8f\u6765\u7ec4\u7ec7\u8868\u7684\uff1a<\/span>\n  1<\/span>\u3001\u4e3b\u952e\u6700\u597d\u7528\u81ea\u589e\u6570\u5b57ID\uff0c\u6548\u7387\u6700\u9ad8\uff1b<\/span>\n  2<\/span>\u3001\u66f4\u65b0\u9891\u7e41\u7684\u7684\u5217\u4e0d\u9002\u5408\u4f5c\u4e3a\u4e3b\u952e\uff1b<\/span>\n  3<\/span>\u3001\u5982\u679c\u7528UUID\u3001MD5\u3001HASH\u3001\u5b57\u7b26\u4e32\u5217\u4f5c\u4e3a\u4e3b\u952e\uff0c\u5219\u65e0\u6cd5\u4fdd\u8bc1\u6570\u636e\u7684\u987a\u5e8f\u589e\u957f\uff1b<\/span><\/code><\/pre>\n
                    \n
                  • \u6570\u636e\u5e93\u548c\u8868\u7684\u5b57\u7b26\u96c6\u7edf\u4e00<\/span><\/span><\/span><\/li>\n<\/ul>\n
                    \u6570\u636e\u5e93\u548c\u8868\u7684\u5b57\u7b26\u96c6\u7edf\u4e00\u4f7f\u7528UTF8\u3002<\/p>\n
                    1<\/span>\u3001\u517c\u5bb9\u6027\u66f4\u597d\u3002<\/span>\n2<\/span>\u3001\u4e0d\u540c\u7684\u5b57\u7b26\u96c6\u8fdb\u884c\u6bd4\u8f83\u524d\u9700\u8981\u8fdb\u884c\u8f6c\u6362\uff0c\u8fd9\u6837\u4f1a\u9020\u6210\u7d22\u5f15\u5931\u6548\u3002<\/span>\n3<\/span>\u3001\u5982\u679c\u5b58\u50a8emoji\u8868\u60c5\u7684\uff0c\u8981\u91c7\u7528utf8mb4\u5b57\u7b26\u96c6\u3002<\/span>\n4<\/span>\u3001\u53ef\u907f\u514d\u5b57\u7b26\u96c6\u8f6c\u6362\u4ea7\u751f\u7684\u4e71\u7801\u3002<\/span><\/code><\/pre>\n
                      \n
                    • \u907f\u514d\u4f7f\u7528select *<\/span><\/span><\/span><\/li>\n<\/ul>\n
                      \u67e5\u8be2\u8bed\u53e5\u8981\u5236\u5b9a\u5177\u4f53\u7684\u5b57\u6bb5\uff0c\u4e0d\u8981\u67e5\u8be2\u6240\u6709\u3002<\/p>\n
                      select<\/span> *\u5f0a\u7aef\uff1a<\/span>\n  1<\/span>\u3001\u589e\u52a0\u4e86\u56de\u8868\u7684\u53ef\u80fd\u6027\uff1b<\/span>\n  2<\/span>\u3001\u67e5\u8be2\u6548\u7387\u4f4e\uff1b<\/span>\n  3<\/span>\u3001\u589e\u52a0\u4e0d\u5fc5\u8981\u7684\u6d88\u8017\uff0c\u6bd4\u5982CPU\u3001IO\u3001\u5185\u5b58\u3001\u7f51\u7edc\u5e26\u5bbd\uff1b<\/span>\n  4<\/span>\u3001\u589e\u52a0\u4e86\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\u7684\u53ef\u80fd\u6027\uff1b<\/span>\n<\/code><\/pre>\n
                        \n
                      • group by\u8bed\u53e5\u6548\u7387\u4f18\u5316<\/span><\/span><\/span><\/li>\n<\/ul>\n
                        \u5148\u8fc7\u6ee4\uff0c\u540e\u5206\u7ec4\uff0c\u8fd9\u6837\u53ef\u4ee5\u5728\u6267\u884c\u5230\u8be5\u8bed\u53e5\u524d\uff0c\u628a\u4e0d\u9700\u8981\u7684\u8bb0\u5f55\u8fc7\u6ee4\u6389\u3002<\/span><\/span><\/p>\n
                        \u6b63\u786e\u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
                        select<\/span> a\uff0cavg<\/span>\uff08b\uff09 from<\/span> user<\/span> \nwhere<\/span> a ='1'<\/span> or<\/span> b = '2'<\/span> \ngroup<\/span> by<\/span> a;<\/code><\/pre>\n
                        \u7981\u7528\uff1agroup by \u5b57\u6bb5 having \u6761\u4ef6;<\/span><\/span><\/p>\n
                          \n
                        • \u7528truncate\u6e05\u7a7a\u8868<\/span><\/span><\/span><\/li>\n<\/ul>\n
                          1\u3001truncate<\/span> table<\/span>\u4e0d\u80fd\u7528\u4e8e\u53c2\u4e0e\u4e86\u7d22\u5f15\u89c6\u56fe\u7684\u8868\u3002\n2<\/span>\u3001truncate<\/span> table<\/span>\u6bd4 delete<\/span>\u5feb\uff0c\u4e14\u7528\u5230\u7684\u7cfb\u7edf\u548c\u4e8b\u52a1\u65e5\u5fd7\u8d44\u6e90\u5c11\u3002\n3<\/span>\u3001delete<\/span>\u4e00\u884c\u6570\u636e\u90fd\u8981\u5728\u4e8b\u52a1\u65e5\u5fd7\u4e2d\u8bb0\u5f55\u4e00\u884c\u3002truncate<\/span> table<\/span>\u901a\u8fc7\u91ca\u653e\u5b58\u50a8\u8868\u6570\u636e\u6240\u7528\u7684\u6570\u636e\u9875\u6765\u5220\u9664\u6570\u636e\uff0c\u5e76\u4e14\u53ea\u5728\u4e8b\u52a1\u65e5\u5fd7\u4e2d\u8bb0\u5f55\u9875\u7684\u91ca\u653e\u3002\n<\/code><\/pre>\n
                            \n
                          • delete\u3001update\u8bed\u53e5\uff0c\u52a0\u4e2alimit\u6216\u8005\u5faa\u73af\u5206\u6279\u6b21\u5220\u9664<\/span><\/span><\/span><\/li>\n<\/ul>\n
                            1\u3001\u964d\u4f4e\u5199\u9519SQL\u6e05\u7a7a\u8868\u6570\u636e\u7684\u98ce\u9669\u3002\n2\u3001SQL\u6548\u7387\u5f88\u53ef\u80fd\u66f4\u9ad8SQL\u4e2d\u52a0\u4e86limit<\/span> 1\uff0c\u5982\u679c\u7b2c\u4e00\u6761\u5c31\u547d\u4e2d\u76ee\u6807return<\/span>\uff0c \u6ca1\u6709limit<\/span>\u7684\u8bdd\uff0c\u8fd8\u4f1a\u7ee7\u7eed\u6267\u884c\u626b\u63cf\u8868\u3002\n3\u3001\u907f\u514d\u957f\u4e8b\u52a1delete\u6267\u884c\u65f6,\u5982\u679cage\u52a0\u4e86\u7d22\u5f15\uff0cMySQL\u4f1a\u5c06\u6240\u6709\u76f8\u5173\u7684\u884c\u52a0\u5199\u9501\u548c\u95f4\u9699\u9501\uff0c\u6240\u6709\u6267\u884c\u76f8\u5173\u884c\u4f1a\u88ab\u9501\u4f4f\uff0c\u5982\u679c\u5220\u9664\u6570\u91cf\u5927\uff0c\u4f1a\u76f4\u63a5\u5f71\u54cd\u76f8\u5173\u4e1a\u52a1\u65e0\u6cd5\u4f7f\u7528\u3002\uff084\uff09\u6570\u636e\u91cf\u5927\u7684\u8bdd\uff0c\u5bb9\u6613\u628aCPU\u6253\u6ee1\u5982\u679c\u4f60\u5220\u9664\u6570\u636e\u91cf\u5f88\u5927\u65f6\uff0c\u4e0d\u52a0 limit<\/span>\u9650\u5236\u4e00\u4e0b\u8bb0\u5f55\u6570\uff0c\u5bb9\u6613\u628acpu\u6253\u6ee1\uff0c\u5bfc\u81f4\u8d8a\u5220\u8d8a\u6162\u3002\uff085\uff09\u9501\u8868\u4e00\u6b21\u6027\u5220\u9664\u592a\u591a\u6570\u636e\uff0c\u53ef\u80fd\u9020\u6210\u9501\u8868\uff0c\u4f1a\u6709lock wait<\/span> timeout exceed\u7684\u9519\u8bef\uff0c\u6240\u4ee5\u5efa\u8bae\u5206\u6279\u64cd\u4f5c\u3002<\/code><\/pre>\n
                              \n
                            • UNION ALL\u64cd\u4f5c\u7b26\u66ff\u4ee3UNION<\/span><\/span><\/span><\/li>\n<\/ul>\n
                              1<\/span>\u3001UNION<\/span> ALL\u66ff\u4ee3UNION\uff0c\u524d\u8005\u53ea\u662f\u7b80\u5355\u7684\u5c06\u4e24\u4e2a\u7ed3\u679c\u5408\u5e76\u540e\u5c31\u8fd4\u56de\u3002<\/span>\n2<\/span>\u3001UNION\u8fde\u63a5\u8868\u540e\u4f1a\u7ed3\u679c\u96c6\u6392\u5e8f\u7136\u540e\u53bb\u6389\u91cd\u590d\u6570\u636e\uff0c\u5728\u8fd4\u56de\u7ed3\u679c\u3002<\/span><\/code><\/pre>\n
                                \n
                              • IN\u4f7f\u7528\u7684\u5b57\u6bb5\u4e0d\u8981\u8fc7\u591a<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                MySQL\u7684IN\u4e2d\u7684\u5e38\u91cf\u5168\u90e8\u5b58\u50a8\u5728\u4e00\u4e2a\u6570\u7ec4\u4e2d\uff0c\u8fd9\u4e2a\u6570\u7ec4\u662f\u6392\u5e8f\u7684\u3002\u5982\u679c\u503c\u8fc7\u591a\uff0c\u4ea7\u751f\u7684\u6d88\u8017\u4e5f\u662f\u6bd4\u8f83\u5927\u7684\u3002\u5982\u679c\u662f\u8fde\u7eed\u7684\u6570\u5b57\uff0c\u53ef\u4ee5\u4f7f\u7528between\u4ee3\u66ff\uff0c\u6216\u8005\u4f7f\u7528\u8fde\u63a5\u67e5\u8be2\u66ff\u6362\u3002<\/span><\/span><\/p>\n
                                  \n
                                • \u6279\u91cf\u63d2\u5165\u4ee3\u66ff\u666e\u901a\u63d2\u5165<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                  \u6279\u91cf\u5904\u7406\u662f\u4e00\u6b21\u4e8b\u52a1\u5f00\u542f\u548c\u63d0\u4ea4\uff0c\u800c\u6bcf\u6b21\u5355\u6761\u63d2\u5165\u90fd\u4f1a\u63d0\u4ea4\u4e00\u6b21\u4e8b\u52a1\u3002<\/span><\/span><\/p>\n
                                  \u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
                                  INSERT<\/span> INTO<\/span> product (id<\/span>,name<\/span>) VALUES<\/span>(1<\/span>,'123123'<\/span>),(2<\/span>,'123123'<\/span>);<\/code><\/pre>\n
                                    \n
                                  • \u7d22\u5f15\u5217\u4e0a\u4e0d\u7528\u5185\u7f6e\u51fd\u6570<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                    \u7d22\u5f15\u5217\u4e0a\u4f7f\u7528\u5185\u7f6e\u51fd\u6570\uff0c\u4f1a\u5bfc\u81f4\u7d22\u5f15\u5931\u6548\u3002<\/span><\/span><\/p>\n
                                      \n
                                    • \u590d\u5408\u7d22\u5f15\u4f7f\u7528\u65f6\u6392\u5e8f\u4f18\u5316<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                      \u6392\u5e8f\u65f6\u5e94\u6309\u7167\u590d\u5408\u7d22\u5f15\u4e2d\u5404\u5217\u7684\u987a\u5e8f\u8fdb\u884c\u6392\u5e8f\uff0c\u5426\u5219\u6392\u5e8f\u6027\u80fd\u4f1a\u6bd4\u8f83\u5dee\u3002<\/span><\/span><\/p>\n
                                        \n
                                      • \u590d\u5408\u7d22\u5f15\u6700\u5de6\u7279\u6027<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                        \u590d\u5408\u7d22\u5f15\u4e0d\u6ee1\u8db3\u6700\u5de6\u539f\u5219\uff0c\u7d22\u5f15\u4e00\u822c\u4f1a\u5931\u6548\u3002<\/p>\n
                                        \u5f53\u521b\u5efa\u4e00\u4e2a\u590d\u5408\u7d22\u5f15\u7684\u65f6\uff0c\u5982\u521b\u5efa(k1,k2,k3)\uff0c\u76f8\u5f53\u4e8e\u521b\u5efa\u4e86\uff08k1\uff09\u3001(k1,k2)\u548c(k1,k2,k3)\u4e09\u4e2a\u7d22\u5f15\uff0c\u8fd9\u5c31\u662f\u6700\u5de6\u5339\u914d\u539f\u5219\u3002<\/code><\/pre>\n
                                        \u4f7f\u7528\u6848\u4f8b\uff1a<\/p>\n
                                        1\u3001\u590d\u5408\u7d22\u5f15\u5168\u4f7f\u7528\uff0c\u6309\u5de6\u4fa7\u987a\u5e8f\u4f7f\u7528\uff0c\u7d22\u5f15\u751f\u6548\nSELECT<\/span> * FROM<\/span> test<\/span> WHERE<\/span> name<\/span>='12321'<\/span> AND<\/span> salary=1000<\/span>\n\n2<\/span>\u3001\u5982\u4e0b\u867d\u8fdd\u80cc\u4e86\u6700\u5de6\u7279\u6027\uff0c\u4f46\u6570\u636e\u5e93\u6267\u884c\u65f6\u4f1a\u8fdb\u884c\u4f18\u5316\uff0c\u4e5f\u4f1a\u4f7f\u7528\u5230\u7d22\u5f15\uff0c\u81ea\u52a8\u7ed9\u98a0\u8986\u8fc7\u6765\nSELECT<\/span> * FROM<\/span> test<\/span> WHERE<\/span> salary=1000<\/span> AND<\/span> NAME<\/span>='12321'<\/span>\n\n\n3<\/span>\u3001\u6ee1\u8db3\u590d\u5408\u7d22\u5f15\u7684\u6700\u5de6\u7279\u6027\nSELECT<\/span> * FROM<\/span> test<\/span> WHERE<\/span> name<\/span>='12312'<\/span>\n\n4<\/span>\u3001\u521b\u5efa\u590d\u5408\u7d22\u5f15\nALTER<\/span> TABLE<\/span> test<\/span> ADD<\/span> INDEX<\/span> idx_name_salary (name<\/span>,salary)\n\n5<\/span>\u3001\u6ca1\u6709\u51fa\u73b0\u5de6\u8fb9\u7684\u5b57\u6bb5\uff0c\u5219\u4e0d\u6ee1\u8db3\u6700\u5de6\u7279\u6027\uff0c\u590d\u5408\u7d22\u5f15\u4f1a\u5931\u6548\nSELECT<\/span> * FROM<\/span> test<\/span> WHERE<\/span> salary=1000<\/span><\/code><\/pre>\n
                                          \n
                                        • \u5fc5\u8981\u7528force index\u5f3a\u5236\u4f7f\u7528\u7d22\u5f15<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                          \u6839\u636e\u81ea\u5df1\u4e1a\u52a1\u9700\u6c42\uff0c\u6709\u65f6\u5019\u53ef\u4ee5\u7528forceindex\u6765\u5f3a\u5236\u4f18\u5316\u5668\u4f7f\u7528\u521b\u5efa\u7684\u7d22\u5f15\u3002<\/span><\/span><\/p>\n
                                            \n
                                          • like\u8bed\u53e5\u4f18\u5316<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                            \u6a21\u7cca\u67e5\u8be2\u7684\u4e00\u4e9b\u573a\u666f\uff0c\u53ef\u80fd\u8ba9\u7d22\u5f15\u5931\u6548\uff0c\u56e0\u6b64\u4f7f\u7528\u65f6\u9700\u8981\u6ce8\u610f\u3002<\/p>\n
                                            1<\/span>\u3001\u5c3d\u91cf\u4e0d\u7528\u907f\u514d\u6a21\u7cca\u67e5\u8be2\uff1b<\/span>\n2<\/span>\u3001\u5168\u6a21\u7cca\u67e5\u8be2\u662f\u65e0\u6cd5\u4f18\u5316\u7684\uff0c\u4e00\u5b9a\u8981\u4f7f\u7528\u7684\u8bdd\u5efa\u8bae\u4f7f\u7528\u641c\u7d22\u5f15\u64ce\u3002<\/span>\n3<\/span>\u3001\u5982\u679c\u5fc5\u987b\u7528like\uff0c\u5e94\u5c3d\u91cf\u91c7\u7528\u53f3\u6a21\u7cca\u67e5\u8be2\uff0c<\/span> \u5373like<\/span> \u2018\u2026%\u2019\uff0c\u662f\u4f1a\u4f7f\u7528\u7d22\u5f15\u7684\uff1b<\/span>\n4<\/span>\u3001\u5de6\u6a21\u7ccalike<\/span> \u2018%...\u2019\u65e0\u6cd5\u76f4\u63a5\u4f7f\u7528\u7d22\u5f15\uff0c\u4f46\u53ef\u4ee5\u5229\u7528reverse<\/span> +<\/span> function<\/span> index\u7684\u5f62\u5f0f\uff0c\u53d8\u5316\u6210<\/span> like<\/span> \u2018\u2026%\u2019\uff1b<\/span><\/code><\/pre>\n
                                              \n
                                            • \u907f\u514d\u4ea7\u751f\u5927\u4e8b\u52a1\u64cd\u4f5c<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                              \u5927\u6279\u91cf\u64cd\u4f5c\u6570\u636e\u65f6\uff0c\u5982\u679c\u5728\u4e00\u4e2a\u4e8b\u52a1\u4e2d\uff0c\u4f1a\u9020\u6210\u8868\u4e2d\u5927\u6279\u91cf\u6570\u636e\u8fdb\u884c\u9501\u5b9a\uff0c\u4ece\u800c\u5bfc\u81f4\u5927\u91cf\u7684\u963b\u585e\uff0c\u5bf9\u6570\u636e\u5e93\u6027\u80fd\u5f71\u54cd\u5f88\u5927\u3002<\/p>\n
                                              \u5c3d\u91cf\u628a\u67e5\u8be2\u8bed\u53e5\u5265\u79bb\u4e8b\u52a1\u903b\u8f91\u3002<\/p>\n
                                                \n
                                              • \u7528\u9884\u7f16\u8bd1\u8bed\u53e5\u64cd\u4f5c\u6570\u636e\u5e93<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                1<\/span>\u3001\u80fd\u89e3\u51b3\u52a8\u6001SQL\u6240\u5e26\u6765\u7684SQL\u6ce8\u5165\u7684\u95ee\u9898\uff1b<\/span>\n2<\/span>\u3001\u9884\u7f16\u8bd1\u8bed\u53e5\u53ef\u4ee5\u91cd\u590d\u4f7f\u7528\u8fd9\u4e9b\u8ba1\u5212\uff0c\u51cf\u5c11SQL\u7f16\u8bd1\u6240\u9700\u8981\u7684\u65f6\u95f4\uff1b<\/span>\n3<\/span>\u3001\u53ea\u4f20\u53c2\u6570\uff0c\u6bd4\u4f20\u9012SQL\u8bed\u53e5\u66f4\u9ad8\u6548\u3002\u76f8\u540c\u8bed\u53e5\u53ef\u4ee5\u4e00\u6b21\u89e3\u6790\uff0c\u591a\u6b21\u4f7f\u7528\uff0c\u63d0\u9ad8\u5904\u7406\u6548\u7387\u3002<\/span><\/code><\/pre>\n
                                                  \n
                                                • \u9891\u7e41\u7684\u67e5\u8be2\u4f18\u5148\u8003\u8651\u4f7f\u7528\u8986\u76d6\u7d22\u5f15<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                  \u8986\u76d6\u7d22\u5f15\uff1a\u5c31\u662f\u5305\u542b\u4e86\u6240\u6709\u67e5\u8be2\u5b57\u6bb5(where,select,ordery by,group by\u5305\u542b\u7684\u5b57\u6bb5)\u7684\u7d22\u5f15\u3002<\/span><\/span><\/p>\n
                                                  \u8986\u76d6\u7d22\u5f15\u7684\u597d\u5904\uff1a<\/span>\n  1<\/span>\u3001\u907f\u514dInnodb\u8868\u8fdb\u884c\u7d22\u5f15\u7684\u4e8c\u6b21\u67e5\u8be2<\/span>\n  2<\/span>\u3001\u53ef\u4ee5\u628a\u968f\u673aIO\u53d8\u6210\u987a\u5e8fIO\u52a0\u5feb\u67e5\u8be2\u6548\u7387<\/span><\/code><\/pre>\n
                                                    \n
                                                  • \u5408\u7406\u9009\u62e9\u7d22\u5f15\u5217\u7684\u987a\u5e8f<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                    1<\/span>\u3001\u4f7f\u7528\u6700\u9891\u7e41\u7684\u5217\u653e\u5230\u8054\u5408\u7d22\u5f15\u7684\u5de6\u4fa7\u3002<\/span>\n2<\/span>\u3001\u533a\u5206\u5ea6\u6700\u9ad8\u7684\u653e\u5728\u8054\u5408\u7d22\u5f15\u7684\u6700\u5de6\u4fa7\uff08\u533a\u5206\u5ea6=\u5217\u4e2d\u4e0d\u540c\u503c\u7684\u6570\u91cf\/\u5217\u7684\u603b\u884c\u6570\uff09\u3002<\/span>\n3<\/span>\u3001\u5c3d\u91cf\u628a\u5b57\u6bb5\u957f\u5ea6\u5c0f\u7684\u5217\u653e\u5728\u8054\u5408\u7d22\u5f15\u7684\u6700\u5de6\u4fa7\uff08\u5b57\u6bb5\u957f\u5ea6\u8d8a\u5c0f\uff0c\u4e00\u9875\u80fd\u5b58\u50a8\u7684\u6570\u636e\u91cf\u8d8a\u5927\uff0cIO\u6027\u80fd\u4e5f\u5c31\u8d8a\u597d\uff09\u3002<\/span>\n<\/code><\/pre>\n
                                                      \n
                                                    • \u7981\u6b62\u8868\u4e2d\u5efa\u7acb\u8fc7\u591a\u7d22\u5f15<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                      MYSQL\u6bcf\u5f20\u8868\u6700\u591a\u5efa16\u4e2a\u7d22\u5f15\u3002\u5e76\u4e0d\u662f\u7d22\u5f15\u8d8a\u591a\u8d8a\u597d\uff0c\u8981\u5408\u7406\u7684\u5efa\u7d22\u5f15\uff0c\u56e0\u4e3a\u6240\u6709\u521b\u5efa\u672c\u8eab\u4e5f\u9700\u8981\u65f6\u95f4\u548c\u5b58\u50a8\u3002<\/p>\n
                                                      \u7d22\u5f15\u4e0d\u5b9c\u592a\u591a\uff0c\u4e00\u822c5\u4e2a\u4ee5\u5185\u3002<\/p>\n
                                                      1<\/span>\u3001\u4e00\u4e2a\u8868\u7684\u7d22\u5f15\u6570\u6700\u597d\u4e0d\u8981\u8d85\u8fc75\u4e2a\uff0c\u82e5\u592a\u591a\u9700\u8981\u8003\u8651\u4e00\u4e9b\u7d22\u5f15\u662f\u5426\u6709\u5b58\u5728\u7684\u5fc5\u8981\uff1b<\/span>\n2<\/span>\u3001\u7d22\u5f15\u53ef\u4ee5\u7406\u89e3\u4e3a\u4e00\u4e2a\u5c31\u662f\u4e00\u5f20\u8868\uff0c\u5176\u53ef\u4ee5\u5b58\u50a8\u6570\u636e\uff0c\u5176\u6570\u636e\u5c31\u8981\u5360\u7a7a\u95f4\uff1b<\/span>\n3<\/span>\u3001\u7d22\u5f15\u5e76\u4e0d\u662f\u8d8a\u591a\u8d8a\u597d\uff0c\u867d\u5176\u63d0\u9ad8\u4e86\u67e5\u8be2\u7684\u6548\u7387\uff0c\u4f46\u5374\u4f1a\u964d\u4f4e\u63d2\u5165\u548c\u66f4\u65b0\u7684\u6548\u7387\uff1b<\/span>\n4<\/span>\u3001\u7d22\u5f15\u8868\u7684\u6570\u636e\u662f\u6392\u5e8f\u7684\uff0c\u6392\u5e8f\u4e5f\u662f\u8981\u82b1\u65f6\u95f4\u7684\uff1b<\/span>\n5<\/span>\u3001insert\u6216update\u65f6\u6709\u53ef\u80fd\u4f1a\u91cd\u5efa\u7d22\u5f15\uff0c\u5982\u679c\u6570\u636e\u91cf\u5de8\u5927\uff0c\u91cd\u5efa\u5c06\u8fdb\u884c\u8bb0\u5f55\u7684\u91cd\u65b0\u6392\u5e8f\uff0c\u6240\u4ee5\u5efa\u7d22\u5f15\u9700\u8981\u614e\u91cd\u8003\u8651\uff0c\u89c6\u5177\u4f53\u60c5\u51b5\u6765\u5b9a\uff1b<\/span><\/code><\/pre>\n
                                                        \n
                                                      • \u8fde\u8868\u67e5\u8be2\u8fde\u8868\u907f\u514d\u8fc7\u591a<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                        \u8868\u8fde\u63a5\u4e0d\u5b9c\u592a\u591a\uff0c\u4e00\u822c5\u4e2a\u4ee5\u5185\u3002<\/span><\/span><\/p>\n
                                                        1<\/span>\u3001\u5e94\u8be5\u628a\u8fde\u63a5\u8868\u62c6\u5f00\u6210\u8f83\u5c0f\u7684\u51e0\u4e2a\u6267\u884c\uff0c\u53ef\u8bfb\u6027\u66f4\u9ad8<\/span>\n2<\/span>\u3001\u5982\u679c\u4e00\u5b9a\u9700\u8981\u8fde\u63a5\u5f88\u591a\u8868\u624d\u80fd\u5f97\u5230\u6570\u636e\uff0c\u90a3\u4e48\u610f\u5473\u7740\u8fd9\u662f\u4e2a\u7cdf\u7cd5\u7684\u8bbe\u8ba1\u4e86<\/span>\n3<\/span>\u3001\u963f\u91cc\u89c4\u8303\u4e2d\uff0c\u5efa\u8bae\u591a\u8868\u8054\u67e5\u4e09\u5f20\u8868\u4ee5\u4e0b<\/span>\n4<\/span>\u3001\u5173\u8054\u7684\u8868\u4e2a\u6570\u8d8a\u591a\uff0c\u7f16\u8bd1\u7684\u65f6\u95f4\u548c\u5f00\u9500\u4e5f\u5c31\u8d8a\u5927<\/span>\n5<\/span>\u3001\u6bcf\u6b21\u5173\u8054\u5185\u5b58\u4e2d\u90fd\u751f\u6210\u4e00\u4e2a\u4e34\u65f6<\/span><\/code><\/pre>\n
                                                          \n
                                                        • \u7edf\u4e00SQL\u8bed\u53e5\u7684\u5199\u6cd5<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                          select<\/span> * from<\/span> a;\nselect<\/span> * From<\/span> A;<\/code><\/pre>\n
                                                          \u4e0a\u9762\u7684\u4e24\u6761sql\u8bed\u53e5\uff0c\u5e73\u5e38\u6211\u4eec\u770b\u6765\u662f\u4e00\u6837\u7684\uff0c\u5b9e\u9645\u6570\u636e\u5e93\u4f18\u5316\u5668\u8ba4\u4e3a\u4ed6\u4eec\u662f\u4e0d\u4e00\u6837\u7684\uff0c\u8fd9\u6837\u6570\u636e\u5e93\u89e3\u6790\u5668\u5c31\u4f1a\u89e3\u6790\u4e24\u6b21\uff0c\u751f\u6210\u4e24\u4e2a\u4e0d\u540c\u7684\u6267\u884c\u8ba1\u5212<\/span><\/span>\u3002<\/p>\n
                                                          \u56e0\u6b64\u76f8\u540c\u7684sql\u8bed\u53e5\u8981\u7edf\u4e00\u5199\u6cd5\uff0c\u8fd9\u6837\u53ef\u4ee5\u51cf\u5c11\u6570\u636e\u5e93\u89e3\u6790\u6b21\u6570\uff0c\u907f\u514d\u751f\u4ea7\u4e24\u4e2a\u4e0d\u540c\u6267\u884c\u8ba1\u5212\u3002<\/p>\n
                                                            \n
                                                          • SQL\u8981\u5c3d\u91cf\u7b80\u5355\u5316<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                            SQL\u6267\u884c\u8ba1\u5212\u662f\u53ef\u4ee5\u88ab\u91cd\u7528\u7684\uff0cSQL\u8d8a\u7b80\u5355\uff0c\u88ab\u91cd\u7528\u7684\u6982\u7387\u8d8a\u5927\uff0c\u751f\u6210\u6267\u884c\u8ba1\u5212\u4e5f\u662f\u5f88\u8017\u65f6\u7684\u3002<\/span><\/span><\/p>\n
                                                            \u5d4c\u5957\u5b50\u67e5\u8be2\u30013\u5f20\u8868\u4ee5\u5185\u5173\u8054\u67e5\u8be2\u5e73\u5e38\u5f88\u5e38\u89c1\u3002\u5982\u679c\u8d85\u8fc73\u5c42\u5d4c\u5957\u67e5\u8be2\uff0c\u67e5\u8be2\u4f18\u5316\u5668\u5f88\u5bb9\u6613\u7ed9\u51fa\u9519\u8bef\u7684\u6267\u884c\u8ba1\u5212\uff0c\u5f71\u54cdSQL\u6548\u7387\u3002<\/code><\/pre>\n
                                                              \n
                                                            • \u4e34\u65f6\u8868\u6ce8\u610f\u4e8b\u9879<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                              1\u3001\u5982\u679c\u6570\u636e\u91cf\u4e0d\u5927\uff0c\u4e3a\u4e86\u7f13\u548c\u7cfb\u7edf\u8868\u7684\u8d44\u6e90\uff0c\u5e94\u5148create<\/span> table<\/span>\uff0c\u7136\u540einsert<\/span>\uff1b\n2<\/span>\u3001\u5982\u679c\u4f7f\u7528\u5230\u4e86\u4e34\u65f6\u8868\uff0c\u5728\u5b58\u50a8\u8fc7\u7a0b\u7684\u6700\u540e\u52a1\u5fc5\u5c06\u6240\u6709\u7684\u4e34\u65f6\u8868\u663e\u5f0f\u5220\u9664\u3002\u5148 truncate<\/span> table<\/span> \uff0c\u7136\u540e drop<\/span> table<\/span> \uff0c\u8fd9\u6837\u53ef\u4ee5\u907f\u514d\u7cfb\u7edf\u8868\u7684\u8f83\u957f\u65f6\u95f4\u9501\u5b9a\u3002\n3<\/span>\u3001\u907f\u514d\u9891\u7e41\u521b\u5efa\u548c\u5220\u9664\u4e34\u65f6\u8868\uff0c\u4ee5\u51cf\u5c11\u7cfb\u7edf\u8868\u8d44\u6e90\u7684\u6d88\u8017\uff1b\n4<\/span>\u3001\u5728\u65b0\u5efa\u4e34\u65f6\u8868\u65f6\uff0c\u5982\u679c\u4e00\u6b21\u6027\u63d2\u5165\u6570\u636e\u91cf\u5f88\u5927\uff0c\u90a3\u4e48\u53ef\u4ee5\u4f7f\u7528 select<\/span> into<\/span> \u4ee3\u66ff create<\/span> table<\/span>\uff0c\u907f\u514d\u9020\u6210\u5927\u91cf log<\/span>\uff1b\n<\/code><\/pre>\n
                                                                \n
                                                              • \u5927SQL\u67e5\u8be2\u62c6\u591a\u4e2a\u5c0f\u67e5\u8be2<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                \u901a\u5e38\u4e3a\u4e86\u8fbe\u5230\u66f4\u597d\u7684\u6027\u80fd\u4ee5\u53ca\u66f4\u597d\u7684\u6570\u636e\u63a7\u5236\uff0c\u53ef\u4ee5\u628a\u5927SQL\u67e5\u8be2\u62c6\u591a\u4e2a\u5c0f\u67e5\u8be2\u3002<\/span><\/span><\/p>\n
                                                                  \n
                                                                • explain\u5206\u6790SQL\u6267\u884c\u8ba1\u5212<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                  type\uff1a<\/span>\n \t1<\/span>\u3001all\uff1a\u5168\u8868\u626b\u63cf\uff1b<\/span>\n  2<\/span>\u3001system\uff1a\u8868\u4ec5\u6709\u4e00\u884c\uff0c\u57fa\u672c\u7528\u4e0d\u5230\uff1b<\/span>\n  3<\/span>\u3001eq_ref\uff1a\u5bf9\u4e8e\u6bcf\u4e2a\u6765\u81ea\u4e8e\u524d\u9762\u7684\u8868\u7684\u884c\u7ec4\u5408\uff0c\u4ece\u8be5\u8868\u4e2d\u8bfb\u53d6\u4e00\u884c\u3002\u8fd9\u53ef\u80fd\u662f\u6700\u597d\u7684\u8fde\u63a5\u7c7b\u578b\uff0c\u9664\u4e86const\u7c7b\u578b\uff1b<\/span>\n  4<\/span>\u3001ref\uff1a\u5bf9\u4e8e\u6bcf\u4e2a\u6765\u81ea\u4e8e\u524d\u9762\u7684\u8868\u7684\u884c\u7ec4\u5408\uff0c\u6240\u6709\u6709\u5339\u914d\u7d22\u5f15\u503c\u7684\u884c\u5c06\u4ece\u8fd9\u5f20\u8868\u4e2d\u8bfb\u53d6\uff1b<\/span>\n  5<\/span>\u3001const\uff1a\u8868\u6700\u591a\u4e00\u884c\u6570\u636e\u914d\u5408\uff0c\u4e3b\u952e\u67e5\u8be2\u65f6\u89e6\u53d1\u8f83\u591a\uff1b<\/span>\n  6<\/span>\u3001\u6027\u80fd\u6392\u540d\uff1asystem<\/span> ><\/span> const<\/span> ><\/span> eq_ref<\/span> ><\/span> ref<\/span> ><\/span> range<\/span> ><\/span> index<\/span> ><\/span> all\u3002<\/span>\n  7<\/span>\u3001\u5b9e\u9645sql\u4f18\u5316\u4e2d\uff0c\u6700\u540e\u8fbe\u5230ref\u6216range\u7ea7\u522b\u3002<\/span>\n  8<\/span>\u3001range\uff1a\u53ea\u68c0\u7d22\u7ed9\u5b9a\u8303\u56f4\u7684\u884c\uff0c\u4f7f\u7528\u4e00\u4e2a\u7d22\u5f15\u6765\u9009\u62e9\u884c\u3002\u5f53\u4f7f\u7528=\u3001<>\u3001>\u3001>=\u3001<\u3001<=\u3001IS<\/span> NULL<\/span>\u3001<=>\u3001BETWEEN\u6216\u8005IN\u64cd\u4f5c\u7b26\uff0c\u7528\u5e38\u91cf\u6bd4\u8f83\u5173\u952e\u5b57\u5217\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528range\uff1b<\/span>\n  9<\/span>\u3001index\uff1a\u8be5\u8054\u63a5\u7c7b\u578b\u4e0eALL\u76f8\u540c\uff0c\u9664\u4e86\u53ea\u6709\u7d22\u5f15\u6811\u88ab\u626b\u63cf\u3002\u8fd9\u901a\u5e38\u6bd4ALL\u5feb\uff0c\u56e0\u4e3a\u7d22\u5f15\u6587\u4ef6\u901a\u5e38\u6bd4\u6570\u636e\u6587\u4ef6\u5c0f\uff1b<\/span>\n \nExtra\u5e38\u7528\u5173\u952e\u5b57\uff1a<\/span>\n  1<\/span>\u3001Using<\/span> index\uff1a\u53ea\u4ece\u7d22\u5f15\u6811\u4e2d\u83b7\u53d6\u4fe1\u606f\uff0c\u800c\u4e0d\u9700\u8981\u56de\u8868\u67e5\u8be2\uff1b<\/span>\n \t2<\/span>\u3001Using<\/span> temporary\uff1amysql\u5e38\u5efa\u4e00\u4e2a\u4e34\u65f6\u8868\u6765\u5bb9\u7eb3\u7ed3\u679c\uff0c\u5178\u578b\u60c5\u51b5\u5982\u67e5\u8be2\u5305\u542b\u53ef\u4ee5\u6309\u4e0d\u540c\u60c5\u51b5\u5217\u51fa\u5217\u7684GROUP<\/span> BY<\/span>\n  3<\/span>\u3001\u548cORDER<\/span> BY\u5b50\u53e5\u65f6\uff1b<\/span>\n  4<\/span>\u3001Using<\/span> where\uff1aWHERE\u5b50\u53e5\u7528\u4e8e\u9650\u5236\u54ea\u4e00\u4e2a\u884c\u5339\u914d\u4e0b\u4e00\u4e2a\u8868\u6216\u53d1\u9001\u5230\u5ba2\u6237\u3002\u9664\u975e\u4f60\u4e13\u95e8\u4ece\u8868\u4e2d\u7d22\u53d6\u6216\u68c0\u67e5\u6240\u6709\u884c\uff0c\u5982\u679cExtra\u503c\u4e0d\u4e3aUsing<\/span> where\u5e76\u4e14\u8868\u8054\u63a5\u7c7b\u578b\u4e3aALL\u6216index\uff0c\u67e5\u8be2\u53ef\u80fd\u4f1a\u6709\u4e00\u4e9b\u9519\u8bef\u3002\u9700\u8981\u56de\u8868\u67e5\u8be2\u3002<\/span>\n <\/code><\/pre>\n
                                                                    \n
                                                                  • \u8bfb\u5199\u5206\u79bb\u4e0e\u5206\u5e93\u5206\u8868<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                    \u5f53\u6570\u636e\u91cf\u8fbe\u5230\u4e00\u5b9a\u7684\u6570\u91cf\u4e4b\u540e\uff0c\u901a\u5e38\u7528\u8bfb\u5199\u5206\u79bb\u3001\u5206\u5e93\u3001\u5206\u8868\u5c42\u9762\u6765\u4f18\u5316\u4e86\u3002<\/span><\/span><\/p>\n
                                                                    1<\/span>\u3001\u5206\u8868\u9002\u7528\u4e8e\u4e2d\u7b49\u6570\u636e\u91cf\uff1b<\/span>\n2<\/span>\u3001\u5206\u5e93\u4e0e\u5206\u8868\u4e00\u822c\u662f\u7ed3\u5408\u7740\u7528\uff0c\u9002\u7528\u4e8e\u5927\u6570\u636e\u91cf\u7684\u5b58\u50a8\u4e86\uff0c\u8fd9\u4e5f\u662f\u73b0\u5728\u5927\u578b\u4e92\u8054\u7f51\u516c\u53f8\u89e3\u51b3\u6570\u636e\u5b58\u50a8\u7684\u65b9\u6cd5\u4e4b\u4e00\u3002<\/span>\n3<\/span>\u3001\u8bfb\u5199\u5206\u79bb\u9002\u7528\u4e8e\u8f83\u5c0f\u4e00\u4e9b\u7684\u6570\u636e\u91cf\uff1b<\/span><\/code><\/pre>\n
                                                                      \n
                                                                    • \u6df1\u5206\u9875\u4f18\u5316<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                      \u6df1\u5206\u9875\u4f18\u5316\u65b9\u6848\uff1a<\/span>\u6807\u7b7e\u8bb0\u5f55\u6cd5\u3001\u5ef6\u8fdf\u5173\u8054\u6cd5\u3002<\/span><\/span><\/span><\/p>\n
                                                                      \u4f7f\u7528\u793a\u4f8b\uff1a<\/p>\n
                                                                      1\u3001\u6807\u7b7e\u8bb0\u5f55\u6cd5\uff1a\nSELECT<\/span> id<\/span>, quarantine_num, quar_product_num FROM<\/span> quarantine_detail WHERE<\/span> id<\/span> > 100000<\/span> LIMIT<\/span> 10<\/span>;\n\n2\u3001\u5ef6\u8fdf\u5173\u8054\u6cd5\uff1a\nSELECT<\/span> qd2.id, qd2.quarantine_num, qd2.quar_product_num FROM<\/span> quarantine_detail qd2 INNER<\/span> JOIN<\/span> ( SELECT<\/span> qd1.id FROM<\/span> quarantine_detail qd1 WHERE<\/span> qd1.quarantine_num > 1<\/span> LIMIT<\/span> 120000<\/span>, 10<\/span> ) AS<\/span> a ON<\/span> a.id = qd2.id;<\/code><\/pre>\n
                                                                        \n
                                                                      • MYSQL\u5355\u8868\u6570\u636e\u91cf\u63a7\u5236\u5728500w\u4ee5\u5185<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                        MySQL\u901a\u5e38\u6211\u4eec\u63a7\u5236\u6570\u636e\u91cf\u5c0f\u4e8e500w\uff0c\u8fc7\u5927\u4f1a\u9020\u6210\u4fee\u6539\u8868\u7ed3\u6784\uff0c\u5907\u4efd\uff0c\u6062\u590d\u90fd\u4f1a\u6709\u5f88\u5927\u7684\u95ee\u9898\u3002<\/p>\n
                                                                        1<\/span>\u3001\u65e5\u5fd7\u6570\u636e\uff1a<\/span>\n\t\u53ef\u4ee5\u7528\u5386\u53f2\u6570\u636e\u5f52\u6863\u3002<\/span>\n2<\/span>\u3001\u4e1a\u52a1\u6570\u636e\uff1a<\/span>\n\t\u5206\u5e93\u5206\u8868\u7b49\u63a7\u5236\u6570\u636e\u91cf\u5927\u5c0f\u3002<\/span><\/code><\/pre>\n
                                                                          \n
                                                                        • TEXT\u6216BLOB\u7c7b\u578b\u53ea\u80fd\u4f7f\u7528\u524d\u7f00\u7d22\u5f15<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                          MySQL\u4e2d\u7d22\u5f15\u5b57\u6bb5\u957f\u5ea6\u662f\u6709\u9650\u5236\u7684\uff0c\u56e0\u6b64TEXT\u6216BLOB\u7c7b\u578b\u53ea\u80fd\u4f7f\u7528\u524d\u7f00\u7d22\u5f15\u3002<\/span><\/span><\/p>\n
                                                                            \n
                                                                          • \u628aBLOB\u6216TEXT\u5217\u5265\u79bb\u5230\u6269\u5c55\u8868\u4e2d<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                            Mysql\u5185\u5b58\u4e34\u65f6\u8868\u4e0d\u652f\u6301TEXT\u3001BLOB\u7c7b\u578b\uff0c\u56e0\u6b64\u6b64\u7c7b\u578b\u6570\u636e\u5728\u67e5\u8be2\u4e2d\uff0c\u5c31\u4e0d\u80fd\u7528\u5185\u5b58\u4e34\u65f6\u8868\uff0c\u5fc5\u987b\u7528\u78c1\u76d8\u4e34\u65f6\u8868\u8fdb\u884c\u3002\u800c\u4e14\u6570\u636e\u5e93\u8fd8\u8981\u8fdb\u884c\u4e8c\u6b21\u67e5\u8be2\uff0csql\u6027\u80fd\u5c31\u663e\u5f97\u5f88\u5dee\u3002<\/code><\/pre>\n
                                                                            \u6240\u4ee5\u6700\u597d\u628a\u628aBLOB\u6216TEXT\u5217\u5265\u79bb\u5230\u5355\u72ec\u7684\u6269\u5c55\u8868\u4e2d\u5b58\u50a8\u3002<\/span><\/span><\/p>\n
                                                                              \n
                                                                            • \u7981\u6b62\u5728\u6570\u636e\u5e93\u4e2d\u5b58\u50a8\u56fe\u7247\uff0c\u6587\u4ef6\u7b49\u5927\u7684\u4e8c\u8fdb\u5236\u6570\u636e<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                              \u901a\u5e38\u6587\u4ef6\u5f88\u5927\uff0c\u4f1a\u77ed\u65f6\u95f4\u5185\u9020\u6210\u6570\u636e\u91cf\u5feb\u901f\u589e\u957f\uff0c\u6570\u636e\u5e93\u8fdb\u884c\u6570\u636e\u5e93\u8bfb\u53d6\u65f6\uff0c\u901a\u5e38\u4f1a\u8fdb\u884c\u5927\u91cf\u7684\u968f\u673aIO\u64cd\u4f5c\uff0c\u6587\u4ef6\u5f88\u5927\u65f6\uff0cIO\u64cd\u4f5c\u5f88\u8017\u65f6\u3002<\/code><\/pre>\n
                                                                              \u901a\u5e38\u5b58\u50a8\u6587\u4ef6\u5230\u6587\u4ef6\u5b58\u50a8\u670d\u52a1\u5668\u6216\u8005MongoDB\u7b49\u3002<\/p>\n
                                                                                \n
                                                                              • \u8868\u5c3d\u91cf\u4e0d\u8981\u5efa\u9884\u7559\u5b57\u6bb5<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                                1<\/span>\u3001\u5bf9\u9884\u7559\u5b57\u6bb5\u7c7b\u578b\u7684\u4fee\u6539\uff0c\u4f1a\u5bf9\u8868\u8fdb\u884c\u9501\u5b9a\uff1b<\/span>\n2<\/span>\u3001\u9884\u7559\u5b57\u6bb5\u7684\u547d\u540d\u5f88\u96be\u505a\u5230\u89c1\u540d\u8bc6\u4e49\uff1b<\/span>\n3<\/span>\u3001\u9884\u7559\u5b57\u6bb5\u65e0\u6cd5\u786e\u8ba4\u5b58\u50a8\u7684\u6570\u636e\u7c7b\u578b\uff0c\u6240\u4ee5\u65e0\u6cd5\u9009\u62e9\u5408\u9002\u7684\u7c7b\u578b\uff1b<\/span><\/code><\/pre>\n
                                                                                  \n
                                                                                • \u5c3d\u91cf\u505a\u5230\u51b7\u70ed\u6570\u636e\u5206\u79bb\uff0c\u51cf\u5c0f\u8868\u7684\u5bbd\u5ea6<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                                  Mysql\u9650\u5236\u6bcf\u4e2a\u8868\u6700\u591a\u5b58\u50a84096\u5217\uff0c\u5e76\u4e14\u6bcf\u4e00\u884c\u6570\u636e\u7684\u5927\u5c0f\u4e0d\u80fd\u8d85\u8fc765535\u5b57\u8282.<\/p>\n
                                                                                  1<\/span>\u3001\u7ecf\u5e38\u4e00\u8d77\u4f7f\u7528\u7684\u5217\u653e\u5230\u4e00\u4e2a\u8868\u4e2d\uff08\u907f\u514d\u66f4\u591a\u7684\u5173\u8054\u64cd\u4f5c\uff09\u3002<\/span>\n2<\/span>\u3001\u66f4\u6709\u6548\u7684\u5229\u7528\u7f13\u5b58\uff0c\u907f\u514d\u8bfb\u5165\u65e0\u7528\u7684\u51b7\u6570\u636e\uff1b<\/span>\n3<\/span>\u3001\u51cf\u5c11\u78c1\u76d8IO,\u4fdd\u8bc1\u70ed\u6570\u636e\u7684\u5185\u5b58\u7f13\u5b58\u547d\u4e2d\u7387\uff08\u8868\u8d8a\u5bbd\uff0c\u628a\u8868\u88c5\u8f7d\u8fdb\u5185\u5b58\u7f13\u51b2\u6c60\u65f6\u6240\u5360\u7528\u7684\u5185\u5b58\u4e5f\u5c31\u8d8a\u5927,\u4e5f\u4f1a\u6d88\u8017\u66f4\u591a\u7684IO\uff09\uff1b<\/span><\/code><\/pre>\n
                                                                                    \n
                                                                                  • \u8c28\u614e\u7528Mysql\u5206\u533a\u8868<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                                    1<\/span>\u3001\u8c28\u614e\u9009\u62e9\u5206\u533a\u952e\uff0c\u8de8\u5206\u533a\u67e5\u8be2\u6548\u7387\u53ef\u80fd\u66f4\u4f4e\uff1b<\/span>\n2<\/span>\u3001\u5efa\u8bae\u91c7\u7528\u7269\u7406\u5206\u8868\u7684\u65b9\u5f0f\u7ba1\u7406\u5927\u6570\u636e\u3002<\/span>\n3<\/span>\u3001\u5206\u533a\u8868\u5728\u7269\u7406\u4e0a\u8868\u73b0\u4e3a\u591a\u4e2a\u6587\u4ef6\uff0c\u5728\u903b\u8f91\u4e0a\u8868\u73b0\u4e3a\u4e00\u4e2a\u8868\uff1b<\/span><\/code><\/pre>\n
                                                                                      \n
                                                                                    • \u5e38\u89c1\u5176\u5b83\u4f18\u5316<\/span><\/span><\/span><\/li>\n<\/ul>\n
                                                                                      1<\/span>\u3001SQL\u4e66\u5199\u683c\u5f0f\uff0c\u5173\u952e\u5b57\u5927\u5c0f\u4fdd\u6301\u4e00\u81f4\uff0c\u4f7f\u7528\u7f29\u8fdb\u3002<\/span>\n2<\/span>\u3001\u5f88\u591a\u65f6\u5019\u7528<\/span> exists<\/span> \u4ee3\u66ff<\/span> in<\/span> \u662f\u4e00\u4e2a\u597d\u7684\u9009\u62e9<\/span>\n3<\/span>\u3001where\u540e\u9762\u7684\u5b57\u6bb5\uff0c\u7559\u610f\u5176\u6570\u636e\u7c7b\u578b\u7684\u9690\u5f0f\u8f6c\u6362\u3002<\/span>\n4<\/span>\u3001\u4fee\u6539\u6216\u5220\u9664\u91cd\u8981\u6570\u636e\u524d\uff0c\u8981\u5148\u5907\u4efd\u3002<\/span>\n5<\/span>\u3001\u5982\u679c\u6392\u5e8f\u5b57\u6bb5\u6ca1\u6709\u7528\u5230\u7d22\u5f15\uff0c\u5c31\u5c3d\u91cf\u5c11\u6392\u5e8f<\/span>\n6<\/span>\u3001\u5f53\u53ea\u9700\u8981\u4e00\u6761\u6570\u636e\u7684\u65f6\u5019\uff0c\u4f7f\u7528limit<\/span> 1limit<\/span> 1<\/span>\n\t\u53ef\u4ee5\u907f\u514d\u5168\u8868\u626b\u63cf\uff0c\u627e\u5230\u5bf9\u5e94\u7ed3\u679c\u5c31\u4e0d\u4f1a\u518d\u7ee7\u7eed\u626b\u63cf\u4e86\u3002<\/span>\n\n7<\/span>\u3001\u6240\u6709\u8868\u548c\u5b57\u6bb5\u90fd\u9700\u8981\u6dfb\u52a0\u6ce8\u91ca\u4f7f\u7528comment\u4ece\u53e5\u6dfb\u52a0\u8868\u548c\u5217\u7684\u5907\u6ce8\uff0c\u4ece\u4e00\u5f00\u59cb\u5c31\u8fdb\u884c\u6570\u636e\u5b57\u5178\u7684\u7ef4\u62a4\u3002<\/span>\n8<\/span>\u3001\u4f2a\u5220\u9664\u8bbe\u8ba1<\/span>\n9<\/span>\u3001\u5c3d\u91cf\u907f\u514d\u4f7f\u7528\u6e38\u6807\u56e0\u4e3a\u6e38\u6807\u7684\u6548\u7387\u8f83\u5dee\uff0c\u5982\u679c\u6e38\u6807\u64cd\u4f5c\u7684\u6570\u636e\u8d85\u8fc71\u4e07\u884c\uff0c\u90a3\u4e48\u5c31\u5e94\u8be5\u8003\u8651\u6539\u5199\u3002<\/span>\n10<\/span>\u3001\u5c3d\u91cf\u628a\u6240\u6709\u5217\u5b9a\u4e49\u4e3aNOT<\/span> NULL<\/span>\n\tNOT<\/span> NULL<\/span>\u5217\u66f4\u8282\u7701\u7a7a\u95f4\uff0cNULL\u5217\u9700\u8981\u4e00\u4e2a\u989d\u5916\u5b57\u8282\u4f5c\u4e3a\u5224\u65ad\u662f\u5426\u4e3a<\/span> NULL<\/span>\u7684\u6807\u5fd7\u4f4d\u3002NULL<\/span>\n\u5217\u9700\u8981\u6ce8\u610f\u7a7a\u6307\u9488\u95ee\u9898\uff0cNULL\u5217\u5728\u8ba1\u7b97\u548c\u6bd4\u8f83\u7684\u65f6\u5019\uff0c\u9700\u8981\u6ce8\u610f\u7a7a\u6307\u9488\u95ee\u9898\u3002<\/span>\n11<\/span>\u3001\u7d22\u5f15\u4e0d\u9002\u5408\u5efa\u5728\u6709\u5927\u91cf\u91cd\u590d\u6570\u636e\u7684\u5b57\u6bb5\u4e0a\uff0c\u6bd4\u5982\u6027\u522b\uff0c\u6392\u5e8f\u5b57\u6bb5\u5e94\u521b\u5efa\u7d22\u5f15<\/span><\/code><\/pre>\n
                                                                                      \n
                                                                                      \u672c\u7bc7\u6587\u7ae0\u6765\u6e90\u4e8e\u5fae\u4fe1\u516c\u4f17\u53f7: IT\u594b\u6597\u7684\u9752\u5e74<\/p><\/blockquote>\n<\/div>\n","raw":"","protected":false},"excerpt":{"rendered":"
                                                                                      1 MySQL\u7684\u6267\u884c\u6d41\u7a0b \u4e3a\u4e86\u66f4\u597d\u7684\u53d6\u4f18\u5316SQL\uff0c\u8fd9\u91cc\u5148\u603b\u7ed3\u4e86\u4e00\u4e0bSQL\u6267\u884c\u6d41\u7a0b\uff1a 1\u3001\u5ba2\u6237\u7aef\u8bf7\u6c42\u5230\u670d\u52a1\u7aef\uff0c\u670d\u52a1\u7aef\u901a\u8fc7\u6570\u636e\u5e93\u8fde\u63a5\u6c60 …<\/p>\n","protected":false},"author":1,"featured_media":323,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[3],"tags":[],"class_list":["post-326","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mysql"],"post_thumbnail_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004630240-150x150.jpeg","content_first_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004632416.png","post_medium_image_300":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004630240-300x300.jpeg","post_thumbnail_image_624":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004630240.jpeg","post_frist_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004632416.png","post_medium_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004630240-300x300.jpeg","post_large_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004630240.jpeg","post_full_image":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004630240.jpeg","post_all_images":[{"imagesurl":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004632416.png","id":"image0"},{"imagesurl":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230528004632416.png","id":"image1"}],"videoAdId":"","listAd":"0","listAdId":"","listAdEvery":6,"total_comments":0,"category_name":"MySQL","post_date":"2023-05-27","like_count":"0","praiseWord":"\u9f13\u52b1","copyright_state":"","excitationAd":"0","rewardedVideoAdId":"","detailAdId":"","detailAd":"0","enterpriseMinapp":"0","audios":[],"postImageUrl":"https:\/\/wp-moto-1258805347.cos.ap-shanghai.myqcloud.com\/2023\/05\/20230519082947553.jpg","avatarurls":[],"related_posts":null,"pageviews":232,"next_post_id":470,"next_post_title":"1.8w \u5b57\u7684 SQL \u4f18\u5316\u5927\u5168","previous_post_id":354,"previous_post_title":"SQL\u9ad8\u7ea7\u7bc7\uff5e\u8054\u5408\u67e5\u8be2","_links":{"self":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/326","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/comments?post=326"}],"version-history":[{"count":0,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/posts\/326\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/media\/323"}],"wp:attachment":[{"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/media?parent=326"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/categories?post=326"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xinchewhd.com.cn\/index.php\/wp-json\/wp\/v2\/tags?post=326"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}