{"id":138393,"date":"2024-10-31T14:06:24","date_gmt":"2024-10-31T06:06:24","guid":{"rendered":"https:\/\/server.hk\/cnblog\/138393\/"},"modified":"2024-10-31T14:06:25","modified_gmt":"2024-10-31T06:06:25","slug":"sql-server%e9%81%8d%e6%ad%b7%e8%a1%a8%e4%b8%8d%e7%94%a8%e6%b8%b8%e6%a8%99%e5%92%8c%e8%87%a8%e6%99%82%e8%a1%a8%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/138393\/","title":{"rendered":"sql server\u904d\u6b77\u8868\u4e0d\u7528\u6e38\u6a19\u548c\u81e8\u6642\u8868\u7684\u65b9\u6cd5"},"content":{"rendered":"

SQL Server\u904d\u6b77\u8868\u4e0d\u7528\u6e38\u6a19\u548c\u81e8\u6642\u8868\u7684\u65b9\u6cd5<\/h1>\n

\u5728SQL Server\u4e2d\uff0c\u904d\u6b77\u8868\u7684\u9700\u6c42\u7d93\u5e38\u51fa\u73fe\uff0c\u5c24\u5176\u662f\u5728\u9700\u8981\u5c0d\u6bcf\u4e00\u884c\u6578\u64da\u9032\u884c\u64cd\u4f5c\u6642\u3002\u50b3\u7d71\u4e0a\uff0c\u958b\u767c\u8005\u53ef\u80fd\u6703\u4f7f\u7528\u6e38\u6a19\u6216\u81e8\u6642\u8868\u4f86\u9054\u6210\u9019\u4e00\u76ee\u7684\u3002\u7136\u800c\uff0c\u9019\u4e9b\u65b9\u6cd5\u5728\u6027\u80fd\u548c\u53ef\u8b80\u6027\u4e0a\u53ef\u80fd\u5b58\u5728\u4e00\u4e9b\u554f\u984c\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e00\u4e9b\u4e0d\u4f7f\u7528\u6e38\u6a19\u548c\u81e8\u6642\u8868\u7684\u66ff\u4ee3\u65b9\u6cd5\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u9ad8\u6548\u5730\u8655\u7406\u6578\u64da\u3002<\/p>\n

1. \u4f7f\u7528CTE\uff08\u516c\u7528\u8868\u8868\u9054\u5f0f\uff09<\/h2>\n

\u516c\u7528\u8868\u8868\u9054\u5f0f\uff08CTE\uff09\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u7528\u4f86\u7c21\u5316\u67e5\u8a62\u4e26\u63d0\u9ad8\u53ef\u8b80\u6027\u3002CTE\u5141\u8a31\u958b\u767c\u8005\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5b9a\u7fa9\u4e00\u500b\u81e8\u6642\u7d50\u679c\u96c6\uff0c\u7136\u5f8c\u5728\u5f8c\u7e8c\u7684\u67e5\u8a62\u4e2d\u5f15\u7528\u5b83\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u4f7f\u7528\u6e38\u6a19\u7684\u8907\u96dc\u6027\u3002<\/p>\n

WITH CTE_Example AS (\n    SELECT Id, Name, Value\n    FROM YourTable\n)\nSELECT Id, Name, Value * 2 AS NewValue\nFROM CTE_Example;<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u9996\u5148\u5b9a\u7fa9\u4e86\u4e00\u500bCTE\uff0c\u7136\u5f8c\u5728\u4e3b\u67e5\u8a62\u4e2d\u4f7f\u7528\u5b83\u4f86\u8a08\u7b97\u6bcf\u500b\u503c\u7684\u5169\u500d\u3002\u9019\u7a2e\u65b9\u6cd5\u4e0d\u50c5\u7c21\u5316\u4e86\u67e5\u8a62\uff0c\u9084\u63d0\u9ad8\u4e86\u6027\u80fd\u3002<\/p>\n
2. \u4f7f\u7528JOIN\u64cd\u4f5c<\/h2>\n
JOIN\u64cd\u4f5c\u53ef\u4ee5\u7528\u4f86\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u540c\u6642\u8655\u7406\u591a\u500b\u8868\u7684\u6578\u64da\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u4f7f\u7528\u81e8\u6642\u8868\u4f86\u5b58\u5132\u4e2d\u9593\u7d50\u679c\u3002<\/p>\n
SELECT a.Id, a.Name, b.Value\nFROM TableA a\nJOIN TableB b ON a.Id = b.AId;<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u901a\u904eJOIN\u64cd\u4f5c\u5c07\u5169\u500b\u8868\u7684\u6578\u64da\u7d50\u5408\u5728\u4e00\u8d77\uff0c\u5f9e\u800c\u907f\u514d\u4e86\u4f7f\u7528\u81e8\u6642\u8868\u7684\u9700\u8981\u3002<\/p>\n
3. \u4f7f\u7528\u7a97\u53e3\u51fd\u6578<\/h2>\n
\u7a97\u53e3\u51fd\u6578\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5728\u4e0d\u9700\u8981\u6e38\u6a19\u7684\u60c5\u6cc1\u4e0b\u9032\u884c\u884c\u7d1a\u8a08\u7b97\u3002\u7a97\u53e3\u51fd\u6578\u5141\u8a31\u958b\u767c\u8005\u5728\u67e5\u8a62\u4e2d\u5c0d\u6bcf\u4e00\u884c\u9032\u884c\u8a08\u7b97\uff0c\u800c\u4e0d\u9700\u8981\u986f\u5f0f\u5730\u904d\u6b77\u6bcf\u4e00\u884c\u3002<\/p>\n
SELECT Id, Name, Value,\n       ROW_NUMBER() OVER (ORDER BY Value) AS RowNum\nFROM YourTable;<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u70ba\u6bcf\u4e00\u884c\u5206\u914d\u4e00\u500b\u884c\u865f\uff0c\u6839\u64daValue\u7684\u6392\u5e8f\u3002\u9019\u6a23\u7684\u8a08\u7b97\u53ef\u4ee5\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5b8c\u6210\uff0c\u907f\u514d\u4e86\u4f7f\u7528\u6e38\u6a19\u7684\u8907\u96dc\u6027\u3002<\/p>\n
4. \u4f7f\u7528CASE\u8a9e\u53e5<\/h2>\n
CASE\u8a9e\u53e5\u53ef\u4ee5\u7528\u4f86\u5728\u67e5\u8a62\u4e2d\u9032\u884c\u689d\u4ef6\u908f\u8f2f\u8655\u7406\uff0c\u9019\u6a23\u53ef\u4ee5\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5b8c\u6210\u591a\u500b\u64cd\u4f5c\uff0c\u800c\u4e0d\u9700\u8981\u4f7f\u7528\u6e38\u6a19\u6216\u81e8\u6642\u8868\u3002<\/p>\n
SELECT Id, Name,\n       CASE \n           WHEN Value > 100 THEN 'High'\n           WHEN Value > 50 THEN 'Medium'\n           ELSE 'Low'\n       END AS ValueCategory\nFROM YourTable;<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u6839\u64daValue\u7684\u5927\u5c0f\u70ba\u6bcf\u4e00\u884c\u5206\u914d\u4e86\u4e00\u500b\u985e\u5225\u3002\u9019\u6a23\u7684\u8655\u7406\u53ef\u4ee5\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5b8c\u6210\uff0c\u7c21\u5316\u4e86\u908f\u8f2f\u3002<\/p>\n
5. \u4f7f\u7528INSERT INTO SELECT<\/h2>\n
\u5982\u679c\u9700\u8981\u5c07\u67e5\u8a62\u7d50\u679c\u63d2\u5165\u5230\u53e6\u4e00\u500b\u8868\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528INSERT INTO SELECT\u8a9e\u53e5\uff0c\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u4f7f\u7528\u81e8\u6642\u8868\u3002<\/p>\n
INSERT INTO TargetTable (Id, Name, Value)\nSELECT Id, Name, Value * 2\nFROM SourceTable;<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u5f9eSourceTable\u4e2d\u9078\u64c7\u6578\u64da\u4e26\u63d2\u5165\u5230TargetTable\u4e2d\uff0c\u4e26\u5728\u63d2\u5165\u6642\u9032\u884c\u8a08\u7b97\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728SQL Server\u4e2d\uff0c\u6709\u591a\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u904d\u6b77\u8868\u800c\u4e0d\u4f7f\u7528\u6e38\u6a19\u548c\u81e8\u6642\u8868\u3002\u4f7f\u7528CTE\u3001JOIN\u64cd\u4f5c\u3001\u7a97\u53e3\u51fd\u6578\u3001CASE\u8a9e\u53e5\u4ee5\u53caINSERT INTO SELECT\u7b49\u6280\u8853\uff0c\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u7684\u6027\u80fd\u548c\u53ef\u8b80\u6027\u3002\u9019\u4e9b\u65b9\u6cd5\u4e0d\u50c5\u80fd\u5920\u7c21\u5316\u4ee3\u78bc\uff0c\u9084\u80fd\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u6548\u7387\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u8655\u7406\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528\u9999\u6e2fVPS<\/a>\u4f86\u904b\u884c\u60a8\u7684SQL Server\u5be6\u4f8b\uff0c\u4eab\u53d7\u66f4\u5feb\u7684\u6578\u64da\u8655\u7406\u901f\u5ea6\u548c\u66f4\u9ad8\u7684\u53ef\u9760\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22\u5728SQL Server\u4e2d\u904d\u6b77\u8868\u7684\u9ad8\u6548\u65b9\u6cd5\uff0c\u7121\u9700\u4f7f\u7528\u6e38\u6a19\u548c\u81e8\u6642\u8868\uff0c\u63d0\u5347\u67e5\u8a62\u6027\u80fd\u8207\u7c21\u5316\u4ee3\u78bc\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-138393","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138393","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=138393"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138393\/revisions"}],"predecessor-version":[{"id":138394,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138393\/revisions\/138394"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=138393"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=138393"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=138393"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}