{"id":168815,"date":"2024-11-06T16:27:25","date_gmt":"2024-11-06T08:27:25","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168815\/"},"modified":"2024-11-06T16:27:26","modified_gmt":"2024-11-06T08:27:26","slug":"transact-sql-%e8%aa%9e%e5%8f%a5%e9%81%8d%e6%ad%b7%e7%b5%90%e6%9e%9c%e9%9b%86%e7%9a%84%e4%b8%89%e7%a8%ae%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168815\/","title":{"rendered":"Transact-SQL \u8a9e\u53e5\u904d\u6b77\u7d50\u679c\u96c6\u7684\u4e09\u7a2e\u65b9\u6cd5"},"content":{"rendered":"

Transact-SQL \u8a9e\u53e5\u904d\u6b77\u7d50\u679c\u96c6\u7684\u4e09\u7a2e\u65b9\u6cd5<\/h1>\n

\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u4e2d\uff0cTransact-SQL\uff08T-SQL\uff09\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u67e5\u8a62\u8a9e\u8a00\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc Microsoft SQL Server \u548c Azure SQL Database\u3002\u7576\u6211\u5011\u9700\u8981\u904d\u6b77\u7d50\u679c\u96c6\u6642\uff0cT-SQL \u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u9054\u6210\u9019\u4e00\u76ee\u7684\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u4e09\u7a2e\u5e38\u898b\u7684\u904d\u6b77\u7d50\u679c\u96c6\u7684\u65b9\u6cd5\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u7bc4\u4f8b\u4ee3\u78bc\u3002<\/p>\n

\u65b9\u6cd5\u4e00\uff1a\u4f7f\u7528\u6e38\u6a19\uff08Cursor\uff09<\/h2>\n

\u6e38\u6a19\u662f\u4e00\u7a2e\u7528\u65bc\u9010\u884c\u8655\u7406\u67e5\u8a62\u7d50\u679c\u96c6\u7684\u8cc7\u6599\u7d50\u69cb\u3002\u4f7f\u7528\u6e38\u6a19\u53ef\u4ee5\u8b93\u958b\u767c\u8005\u5728\u7d50\u679c\u96c6\u4e2d\u9010\u884c\u64cd\u4f5c\uff0c\u9019\u5728\u9700\u8981\u5c0d\u6bcf\u4e00\u884c\u9032\u884c\u8907\u96dc\u8655\u7406\u6642\u7279\u5225\u6709\u7528\u3002<\/p>\n

DECLARE @EmployeeName NVARCHAR(100);\nDECLARE EmployeeCursor CURSOR FOR\nSELECT Name FROM Employees;\n\nOPEN EmployeeCursor;\nFETCH NEXT FROM EmployeeCursor INTO @EmployeeName;\n\nWHILE @@FETCH_STATUS = 0\nBEGIN\n    PRINT @EmployeeName;  -- \u5728\u9019\u88e1\u53ef\u4ee5\u9032\u884c\u5176\u4ed6\u64cd\u4f5c\n    FETCH NEXT FROM EmployeeCursor INTO @EmployeeName;\nEND\n\nCLOSE EmployeeCursor;\nDEALLOCATE EmployeeCursor;<\/code><\/pre>\n
\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u9996\u5148\u5ba3\u544a\u4e86\u4e00\u500b\u6e38\u6a19\uff0c\u7136\u5f8c\u4f7f\u7528 FETCH NEXT \u9010\u884c\u7372\u53d6\u54e1\u5de5\u7684\u540d\u5b57\uff0c\u4e26\u5728 WHILE \u5faa\u74b0\u4e2d\u9032\u884c\u8655\u7406\u3002\u6700\u5f8c\uff0c\u8a18\u5f97\u95dc\u9589\u548c\u91cb\u653e\u6e38\u6a19\u3002<\/p>\n
\u65b9\u6cd5\u4e8c\uff1a\u4f7f\u7528 WHILE \u5faa\u74b0\u548c\u81e8\u6642\u8868<\/h2>\n
\u53e6\u4e00\u7a2e\u904d\u6b77\u7d50\u679c\u96c6\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 WHILE \u5faa\u74b0\u7d50\u5408\u81e8\u6642\u8868\u3002\u9019\u7a2e\u65b9\u6cd5\u9069\u5408\u65bc\u9700\u8981\u5728\u7d50\u679c\u96c6\u4e0a\u9032\u884c\u591a\u6b21\u64cd\u4f5c\u7684\u60c5\u6cc1\u3002<\/p>\n
CREATE TABLE #TempEmployees (Name NVARCHAR(100));\nINSERT INTO #TempEmployees (Name)\nSELECT Name FROM Employees;\n\nDECLARE @EmployeeName NVARCHAR(100);\nDECLARE @Counter INT = 1;\nDECLARE @TotalRows INT = (SELECT COUNT(*) FROM #TempEmployees);\n\nWHILE @Counter <= @TotalRows\nBEGIN\n    SELECT @EmployeeName = Name FROM #TempEmployees WHERE ROW_NUMBER() OVER (ORDER BY Name) = @Counter;\n    PRINT @EmployeeName;  -- \u5728\u9019\u88e1\u53ef\u4ee5\u9032\u884c\u5176\u4ed6\u64cd\u4f5c\n    SET @Counter = @Counter + 1;\nEND\n\nDROP TABLE #TempEmployees;<\/code><\/pre>\n
\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u9996\u5148\u5275\u5efa\u4e86\u4e00\u500b\u81e8\u6642\u8868\uff0c\u7136\u5f8c\u5c07\u67e5\u8a62\u7d50\u679c\u63d2\u5165\u8a72\u8868\u3002\u63a5\u8457\uff0c\u6211\u5011\u4f7f\u7528 WHILE \u5faa\u74b0\u548c ROW_NUMBER \u51fd\u6578\u4f86\u9010\u884c\u7372\u53d6\u54e1\u5de5\u7684\u540d\u5b57\u3002<\/p>\n
\u65b9\u6cd5\u4e09\uff1a\u4f7f\u7528 FOR XML PATH<\/h2>\n
\u5982\u679c\u9700\u8981\u5c07\u7d50\u679c\u96c6\u8f49\u63db\u70ba\u4e00\u500b\u5b57\u7b26\u4e32\uff0c\u5247\u53ef\u4ee5\u4f7f\u7528 FOR XML PATH \u65b9\u6cd5\u3002\u9019\u7a2e\u65b9\u6cd5\u7279\u5225\u9069\u5408\u65bc\u9700\u8981\u5c07\u591a\u884c\u7d50\u679c\u5408\u4f75\u70ba\u4e00\u884c\u7684\u60c5\u6cc1\u3002<\/p>\n
DECLARE @EmployeeNames NVARCHAR(MAX);\n\nSELECT @EmployeeNames = STRING_AGG(Name, ', ') \nFROM Employees;\n\nPRINT @EmployeeNames;  -- \u8f38\u51fa\u6240\u6709\u54e1\u5de5\u7684\u540d\u5b57\uff0c\u4ee5\u9017\u865f\u5206\u9694<\/code><\/pre>\n
\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u4f7f\u7528 STRING_AGG \u51fd\u6578\u5c07\u6240\u6709\u54e1\u5de5\u7684\u540d\u5b57\u5408\u4f75\u70ba\u4e00\u500b\u5b57\u7b26\u4e32\uff0c\u4e26\u4ee5\u9017\u865f\u5206\u9694\u3002\u9019\u7a2e\u65b9\u6cd5\u7c21\u6f54\u4e14\u9ad8\u6548\uff0c\u9069\u5408\u65bc\u9700\u8981\u5feb\u901f\u7372\u53d6\u7d50\u679c\u7684\u5834\u666f\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728\u672c\u6587\u4e2d\uff0c\u6211\u5011\u63a2\u8a0e\u4e86\u4e09\u7a2e\u4f7f\u7528 Transact-SQL \u904d\u6b77\u7d50\u679c\u96c6\u7684\u65b9\u6cd5\uff1a\u6e38\u6a19\u3001WHILE \u5faa\u74b0\u7d50\u5408\u81e8\u6642\u8868\uff0c\u4ee5\u53ca FOR XML PATH\u3002\u6bcf\u7a2e\u65b9\u6cd5\u90fd\u6709\u5176\u7279\u5b9a\u7684\u61c9\u7528\u5834\u666f\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u6839\u64da\u9700\u6c42\u9078\u64c7\u6700\u5408\u9069\u7684\u65b9\u5f0f\u4f86\u8655\u7406\u8cc7\u6599\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 \u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u8cc7\u6599\u5eab\u7ba1\u7406\u9084\u662f\u7db2\u7ad9\u6258\u7ba1\uff0c\u6211\u5011\u7684 \u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22 Transact-SQL \u4e2d\u904d\u6b77\u7d50\u679c\u96c6\u7684\u4e09\u7a2e\u65b9\u6cd5\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\uff0c\u7c21\u5316\u67e5\u8a62\u64cd\u4f5c\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-168815","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168815","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=168815"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168815\/revisions"}],"predecessor-version":[{"id":168816,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168815\/revisions\/168816"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168815"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168815"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168815"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}