{"id":73099,"date":"2024-02-21T17:14:01","date_gmt":"2024-02-21T09:14:01","guid":{"rendered":"https:\/\/docs.pingcode.com\/?p=73099"},"modified":"2024-02-21T17:14:16","modified_gmt":"2024-02-21T09:14:16","slug":"sql%e8%af%ad%e8%a8%80%e9%ab%98%e7%ba%a7%e6%9f%a5%e8%af%a2%e6%8a%80%e5%b7%a7%e6%9c%89%e5%93%aa%e4%ba%9b","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/73099.html","title":{"rendered":"SQL\u8bed\u8a00\u9ad8\u7ea7\u67e5\u8be2\u6280\u5de7\u6709\u54ea\u4e9b"},"content":{"rendered":"

\"SQL\u8bed\u8a00\u9ad8\u7ea7\u67e5\u8be2\u6280\u5de7\u6709\u54ea\u4e9b\"<\/p>\n

\u5728SQL\u8bed\u8a00\u9ad8\u7ea7\u67e5\u8be2\u6280\u5de7\u4e2d\uff0c\u5e38\u89c1\u7684\u5305\u62ec\u4f7f\u7528\u5b50\u67e5\u8be2\u3001\u5229\u7528JOIN\u6765\u5173\u8054\u591a\u4e2a\u8868\u3001\u5e94\u7528\u7a97\u53e3\u51fd\u6570\u5982ROW_NUMBER()\u3001\u91c7\u7528CTE (Common Table Expressions) \u4ee5\u53ca\u5229\u7528\u9012\u5f52\u67e5\u8be2<\/strong>\u7b49\u65b9\u6cd5\u3002\u5728\u8fd9\u4e9b\u6280\u5de7\u4e2d\uff0c\u4f8b\u5982\uff0c\u5e94\u7528\u7a97\u53e3\u51fd\u6570<\/strong>\u53ef\u4ee5\u5728\u4e0d\u9700\u8981\u5206\u7ec4\u6570\u636e\u7684\u60c5\u51b5\u4e0b\u8ba1\u7b97\u6570\u636e\u7684\u6392\u540d\u6216\u8005\u8fdb\u884c\u6570\u636e\u7684\u5206\u533a\u7edf\u8ba1\uff0c\u8fd9\u662f\u5e38\u89c4\u7684GROUP BY\u6240\u4e0d\u80fd\u5b9e\u73b0\u7684\u3002\u7a97\u53e3\u51fd\u6570\u53ef\u4ee5\u5728SELECT\u8bed\u53e5\u4e2d\u5904\u7406\u6570\u636e\uff0c\u800c\u4e0d\u4f1a\u6539\u53d8\u5b83\u4eec\u5728\u8868\u4e2d\u7684\u663e\u793a\u65b9\u5f0f\uff0c\u8fd9\u4e2a\u7279\u6027\u5728\u8fdb\u884c\u590d\u6742\u62a5\u544a\u65f6\u5c24\u5176\u6709\u7528\u3002<\/p>\n

\u4e00\u3001\u4f7f\u7528\u5b50\u67e5\u8be2<\/strong><\/h2>\n

\u5b50\u67e5\u8be2\u5141\u8bb8\u4f60\u5728SQL\u8bed\u53e5\u4e2d\u5d4c\u5165\u53e6\u4e00\u4e2a\u67e5\u8be2\uff0c\u5b83\u53ef\u4ee5\u7528\u5728SELECT\u3001INSERT\u3001UPDATE\u548cDELETE\u8bed\u53e5\u4e4b\u4e2d\uff0c\u63d0\u9ad8\u67e5\u8be2\u7684\u7075\u6d3b\u6027\u548c\u590d\u6742\u5ea6\u3002\u5b50\u67e5\u8be2\u53ef\u4ee5\u662f\u5355\u884c\u4e5f\u53ef\u4ee5\u662f\u591a\u884c\u67e5\u8be2\uff0c\u901a\u5e38\u7528\u5728WHERE\u6216\u8005HAVING\u5b50\u53e5\u4e2d\u3002<\/p>\n

\u5f53\u5b50\u67e5\u8be2\u4f4d\u4e8eWHERE\u5b50\u53e5\u4e2d<\/strong>\u65f6\uff0c\u5b83\u53ef\u4ee5\u8fd4\u56de\u4e00\u4e2a\u503c\uff0c\u8fd9\u4e2a\u503c\u88ab\u4e0a\u7ea7\u67e5\u8be2\u6240\u4f7f\u7528\u8fdb\u884c\u6761\u4ef6\u7684\u8fc7\u6ee4\u3002\u4f8b\u5982\uff0c\u4f60\u53ef\u4ee5\u627e\u51fa\u9500\u91cf\u8d85\u8fc7\u5e73\u5747\u9500\u91cf\u7684\u4ea7\u54c1\uff0c\u901a\u8fc7\u5728WHERE\u5b50\u53e5\u4e2d\u5d4c\u5165\u8ba1\u7b97\u5e73\u5747\u9500\u91cf\u7684\u5b50\u67e5\u8be2\u3002<\/p>\n

\u4e8c\u3001\u5229\u7528JOIN\u5173\u8054\u591a\u4e2a\u8868<\/strong><\/h2>\n

JOIN\u662fSQL\u4e2d\u7528\u4e8e\u6839\u636e\u4e24\u4e2a\u6216\u591a\u4e2a\u8868\u4e2d\u7684\u5171\u540c\u5b57\u6bb5\u5c06\u6570\u636e\u5408\u5e76\u5230\u4e00\u4e2a\u7ed3\u679c\u96c6\u4e2d\u7684\u64cd\u4f5c\u3002\u6839\u636e\u5173\u8054\u8868\u7684\u65b9\u5f0f\u4e0d\u540c\uff0cJOIN\u53ef\u4ee5\u5206\u4e3a\u5185\u8fde\u63a5\uff08INNER JOIN\uff09\u3001\u5de6\u8fde\u63a5\uff08LEFT JOIN\uff09\u3001\u53f3\u8fde\u63a5\uff08RIGHT JOIN\uff09\u548c\u5168\u8fde\u63a5\uff08FULL JOIN\uff09\u3002<\/p>\n

INNER JOIN\u662f\u6700\u5e38\u7528\u7684JOIN\u7c7b\u578b<\/strong>\uff0c\u5b83\u4ec5\u8fd4\u56de\u4e24\u4e2a\u8868\u4e2d\u5339\u914d\u7684\u884c\u3002\u4f8b\u5982\uff0c\u5982\u679c\u4f60\u9700\u8981\u663e\u793a\u5ba2\u6237\u7684\u8ba2\u5355\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528INNER JOIN\u6839\u636e\u5ba2\u6237ID\u5173\u8054\u5ba2\u6237\u8868\u548c\u8ba2\u5355\u8868\u3002<\/p>\n

\u4e09\u3001\u5e94\u7528\u7a97\u53e3\u51fd\u6570<\/strong><\/h2>\n

\u7a97\u53e3\u51fd\u6570\u80fd\u591f\u80fd\u591f\u5728\u6570\u636e\u5206\u7ec4\u7684\u540c\u65f6\u4fdd\u6301\u884c\u7684\u72ec\u7acb\u6027\uff0c\u5b83\u4eec\u53ef\u4ee5\u7528\u4e8e\u591a\u79cd\u8ba1\u7b97\uff0c\u5982\u6392\u540d\uff08RANK()\uff09\u3001\u5206\u5e03\uff08DISTRIBUTE()\uff09\u4ee5\u53ca\u79fb\u52a8\u5e73\u5747\uff08AVG() OVER(…)\uff09\u7b49\u3002<\/p>\n

ROW_NUMBER()\u662f\u4e00\u79cd\u975e\u5e38\u5b9e\u7528\u7684\u7a97\u53e3\u51fd\u6570<\/strong>\uff0c\u7528\u4e8e\u4e3a\u7ed3\u679c\u96c6\u4e2d\u7684\u884c\u63d0\u4f9b\u4e00\u4e2a\u552f\u4e00\u7684\u5e8f\u53f7\u3002\u4f8b\u5982\uff0c\u5728\u67d0\u4e9b\u4e1a\u52a1\u573a\u666f\u4e0b\uff0c\u6211\u4eec\u53ef\u80fd\u9700\u8981\u6309\u67d0\u79cd\u4e1a\u52a1\u903b\u8f91\u5bf9\u6570\u636e\u884c\u8fdb\u884c\u6392\u5e8f\uff0cROW_NUMBER()\u53ef\u4ee5\u4e3a\u6392\u5e8f\u540e\u7684\u6bcf\u884c\u6570\u636e\u63d0\u4f9b\u4e00\u4e2a\u987a\u5e8f\u53f7\u3002<\/p>\n

\u56db\u3001\u91c7\u7528CTE (Common Table Expressions)<\/strong><\/h2>\n

CTE\u63d0\u4f9b\u4e86\u4e00\u79cd\u4f7f\u7528\u4e34\u65f6\u7ed3\u679c\u96c6\u7684\u65b9\u5f0f\uff0c\u5b83\u662f\u4e00\u79cd\u4e34\u65f6\u7684\u7ed3\u679c\u96c6\uff0c\u4ec5\u5b58\u5728\u4e8e\u6267\u884c\u67e5\u8be2\u7684\u90a3\u4e2a\u4e0a\u4e0b\u6587\u4e2d\u3002\u4f7f\u7528CTE\u80fd\u8ba9\u67e5\u8be2\u66f4\u52a0\u6613\u8bfb\uff0c\u7279\u522b\u662f\u5728\u6267\u884c\u590d\u6742\u7684\u67e5\u8be2\u3001\u591a\u5c42\u6b21\u7684\u5b50\u67e5\u8be2\u6216\u5177\u6709\u9012\u5f52\u903b\u8f91\u7684\u67e5\u8be2\u65f6\u3002<\/p>\n

CTE\u4f7f\u5f97\u67e5\u8be2\u7684\u7ed3\u6784\u66f4\u52a0\u6e05\u6670<\/strong>\uff0c\u56e0\u4e3a\u4f60\u53ef\u4ee5\u5c06\u67e5\u8be2\u5206\u6210\u591a\u4e2a\u903b\u8f91\u4e0a\u7684\u90e8\u5206\uff0c\u5148\u5b9a\u4e49CTE\uff0c\u7136\u540e\u5728\u4e3b\u67e5\u8be2\u4e2d\u5f15\u7528\u8fd9\u4e9bCTE\uff0c\u5c31\u50cf\u5f15\u7528\u771f\u5b9e\u7684\u8868\u6216\u89c6\u56fe\u4e00\u6837\u3002<\/p>\n

\u4e94\u3001\u5229\u7528\u9012\u5f52\u67e5\u8be2<\/strong><\/h2>\n

\u9012\u5f52\u67e5\u8be2\u662f\u901a\u8fc7WITH RECURSIVE\u5b50\u53e5\u6765\u5b9e\u73b0\u7684\u3002\u9012\u5f52\u67e5\u8be2\u901a\u5e38\u7528\u4e8e\u5904\u7406\u5177\u6709\u5c42\u6b21\u7ed3\u6784\u7684\u6570\u636e\uff0c\u5982\u7ec4\u7ec7\u7ed3\u6784\u3001\u76ee\u5f55\u7ed3\u6784\u7b49\u3002<\/p>\n

\u5728\u4f7f\u7528\u9012\u5f52\u67e5\u8be2\u65f6<\/strong>\uff0c\u4f60\u9700\u8981\u5b9a\u4e49\u4e00\u4e2a\u9012\u5f52\u7684CTE\uff0c\u8be5CTE\u5305\u62ec\u4e24\u90e8\u5206\uff1a\u57fa\u51c6\u90e8\u5206\uff08\u7528\u4e8e\u521d\u59cb\u5316\u9012\u5f52\uff09\uff0c\u9012\u5f52\u90e8\u5206\uff08\u7528\u4e8e\u6267\u884c\u9012\u5f52\uff09\u3002\u8fd9\u79cd\u67e5\u8be2\u65b9\u5f0f\u5728\u5904\u7406\u6811\u7ed3\u6784\u6216\u56fe\u7ed3\u6784\u6570\u636e\u65f6\u975e\u5e38\u6709\u6548\u3002<\/p>\n

\u603b\u4e4b\uff0c\u901a\u8fc7\u7075\u6d3b\u8fd0\u7528\u8fd9\u4e9b\u9ad8\u7ea7\u67e5\u8be2\u6280\u5de7\uff0c\u53ef\u4ee5\u5927\u5927\u63d0\u5347SQL\u67e5\u8be2\u7684\u6548\u7387\u4e0e\u590d\u6742\u6027\uff0c\u89e3\u51b3\u5b9e\u9645\u5de5\u4f5c\u4e2d\u7684\u5404\u79cd\u6570\u636e\u5904\u7406\u96be\u9898\u3002<\/p>\n

\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n

\u54ea\u4e9b\u9ad8\u7ea7\u67e5\u8be2\u6280\u5de7\u53ef\u4ee5\u5e94\u7528\u4e8eSQL\u8bed\u8a00\uff1f<\/strong><\/p>\n

1. \u5b50\u67e5\u8be2<\/strong>\uff1a\u901a\u8fc7\u5728\u67e5\u8be2\u8bed\u53e5\u4e2d\u5d4c\u5957\u53e6\u4e00\u4e2a\u67e5\u8be2\uff0c\u53ef\u4ee5\u5b9e\u73b0\u66f4\u590d\u6742\u7684\u6570\u636e\u68c0\u7d22\u548c\u5206\u6790\u3002\u5b50\u67e5\u8be2\u53ef\u4ee5\u7528\u4e8eWhere\u5b50\u53e5\u3001From\u5b50\u53e5\u6216Select\u5b50\u53e5\u4e2d\u3002<\/p>\n

2. \u8054\u5408\u67e5\u8be2<\/strong>\uff1a\u4f7f\u7528UNION\u3001UNION ALL\u3001INTERSECT\u6216EXCEPT\u7b49\u64cd\u4f5c\u7b26\u53ef\u4ee5\u5c06\u591a\u4e2a\u67e5\u8be2\u7ed3\u679c\u5408\u5e76\u6210\u4e00\u4e2a\u7ed3\u679c\u96c6\u3002\u8054\u5408\u67e5\u8be2\u53ef\u4ee5\u7528\u4e8e\u5408\u5e76\u4e0d\u540c\u8868\u7684\u7ed3\u679c\uff0c\u6216\u5bf9\u540c\u4e00\u8868\u8fdb\u884c\u4e0d\u540c\u7684\u7b5b\u9009\u548c\u6392\u5e8f\u3002<\/p>\n

3. \u7a97\u53e3\u51fd\u6570<\/strong>\uff1a\u7a97\u53e3\u51fd\u6570\u53ef\u4ee5\u5bf9\u67e5\u8be2\u7ed3\u679c\u96c6\u4e2d\u7684\u6570\u636e\u8fdb\u884c\u6392\u5e8f\u3001\u5206\u7ec4\u548c\u7edf\u8ba1\uff0c\u540c\u65f6\u4fdd\u7559\u539f\u59cb\u6570\u636e\u987a\u5e8f\u3002\u5e38\u89c1\u7684\u7a97\u53e3\u51fd\u6570\u5305\u62ecROW_NUMBER\u3001RANK\u3001DENSE_RANK\u3001SUM\u3001AVG\u7b49\u3002<\/p>\n

4. \u901a\u7528\u8868\u8868\u8fbe\u5f0f\uff08CTE\uff09<\/strong>\uff1aCTE\u662f\u4e00\u79cd\u4e34\u65f6\u8868\uff0c\u53ef\u4ee5\u5728\u67e5\u8be2\u4e2d\u5b9a\u4e49\u5e76\u591a\u6b21\u5f15\u7528\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002\u901a\u7528\u8868\u8868\u8fbe\u5f0f\u53ef\u4ee5\u5728\u67e5\u8be2\u8bed\u53e5\u4e2d\u5b9e\u73b0\u9012\u5f52\u67e5\u8be2\u548c\u590d\u6742\u7684\u6570\u636e\u5904\u7406\u903b\u8f91\u3002<\/p>\n

5. \u52a8\u6001SQL<\/strong>\uff1a\u901a\u8fc7\u62fc\u63a5\u5b57\u7b26\u4e32\u6216\u4f7f\u7528\u6761\u4ef6\u5224\u65ad\u8bed\u53e5\uff0c\u53ef\u4ee5\u52a8\u6001\u751f\u6210SQL\u67e5\u8be2\u8bed\u53e5\uff0c\u5b9e\u73b0\u7075\u6d3b\u7684\u6570\u636e\u68c0\u7d22\u548c\u64cd\u4f5c\u3002\u52a8\u6001SQL\u53ef\u4ee5\u6839\u636e\u4e0d\u540c\u7684\u6761\u4ef6\u52a8\u6001\u8c03\u6574\u67e5\u8be2\u903b\u8f91\uff0c\u6ee1\u8db3\u5404\u79cd\u67e5\u8be2\u9700\u6c42\u3002<\/p>\n

6. \u7d22\u5f15\u4f18\u5316<\/strong>\uff1a\u5408\u7406\u8bbe\u8ba1\u548c\u4f7f\u7528\u7d22\u5f15\u53ef\u4ee5\u63d0\u9ad8SQL\u67e5\u8be2\u7684\u6027\u80fd\u3002\u53ef\u4ee5\u901a\u8fc7\u5bf9\u5e38\u7528\u67e5\u8be2\u5b57\u6bb5\u521b\u5efa\u7d22\u5f15\u3001\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\u3001\u5b9a\u671f\u7ef4\u62a4\u7d22\u5f15\u7b49\u65b9\u5f0f\u4f18\u5316\u67e5\u8be2\u6027\u80fd\u3002<\/p>\n

7. \u6b63\u5219\u8868\u8fbe\u5f0f<\/strong>\uff1a\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u53ef\u4ee5\u5728SQL\u67e5\u8be2\u4e2d\u5b9e\u73b0\u66f4\u7075\u6d3b\u7684\u6587\u672c\u5339\u914d\u548c\u7b5b\u9009\u3002\u6b63\u5219\u8868\u8fbe\u5f0f\u53ef\u4ee5\u5728Where\u5b50\u53e5\u6216Select\u5b50\u53e5\u4e2d\u5e94\u7528\uff0c\u8fdb\u884c\u6a21\u7cca\u5339\u914d\u6216\u6570\u636e\u63d0\u53d6\u7b49\u64cd\u4f5c\u3002<\/p>\n

8. \u6570\u636e\u900f\u89c6<\/strong>\uff1a\u901a\u8fc7\u4f7f\u7528Pivot\u8868\u8fbe\u5f0f\u53ef\u4ee5\u5c06\u884c\u8f6c\u6362\u4e3a\u5217\uff0c\u5b9e\u73b0\u6570\u636e\u900f\u89c6\u64cd\u4f5c\u3002\u6570\u636e\u900f\u89c6\u53ef\u4ee5\u5c06\u4ea4\u53c9\u8868\u6570\u636e\u91cd\u65b0\u7ec4\u7ec7\uff0c\u4fbf\u4e8e\u6570\u636e\u5206\u6790\u548c\u62a5\u8868\u751f\u6210\u3002<\/p>\n

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