{"id":138395,"date":"2024-10-31T14:07:20","date_gmt":"2024-10-31T06:07:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/138395\/"},"modified":"2024-10-31T14:07:21","modified_gmt":"2024-10-31T06:07:21","slug":"sql-server%e9%81%8d%e6%ad%b7%e8%a1%a8%e4%b8%ad%e8%a8%98%e9%8c%84%e7%9a%84%e5%af%a6%e7%8f%be%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/138395\/","title":{"rendered":"SQL Server\u904d\u6b77\u8868\u4e2d\u8a18\u9304\u7684\u5be6\u73fe\u65b9\u6cd5"},"content":{"rendered":"<h1 id=\"sql-server%e9%81%8d%e6%ad%b7%e8%a1%a8%e4%b8%ad%e8%a8%98%e9%8c%84%e7%9a%84%e5%af%a6%e7%8f%be%e6%96%b9%e6%b3%95-gAeysGGjuH\">SQL Server\u904d\u6b77\u8868\u4e2d\u8a18\u9304\u7684\u5be6\u73fe\u65b9\u6cd5<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u904d\u6b77\u8868\u4e2d\u7684\u8a18\u9304\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u70ba\u4e86\u6578\u64da\u5206\u6790\u3001\u5831\u544a\u751f\u6210\uff0c\u9084\u662f\u6578\u64da\u9077\u79fb\uff0c\u4e86\u89e3\u5982\u4f55\u6709\u6548\u5730\u904d\u6b77SQL Server\u4e2d\u7684\u8868\u8a18\u9304\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u5728SQL Server\u4e2d\u904d\u6b77\u8868\u8a18\u9304\u7684\u65b9\u6cd5\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u793a\u4f8b\u4ee3\u78bc\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8%e6%b8%b8%e6%a8%99%ef%bc%88cursor%ef%bc%89-gAeysGGjuH\">1. \u4f7f\u7528\u6e38\u6a19\uff08Cursor\uff09<\/h2>\n<p>\u6e38\u6a19\u662f\u4e00\u7a2e\u5728SQL Server\u4e2d\u9010\u884c\u8655\u7406\u67e5\u8a62\u7d50\u679c\u7684\u5de5\u5177\u3002\u96d6\u7136\u6e38\u6a19\u7684\u6027\u80fd\u901a\u5e38\u4e0d\u5982\u6279\u91cf\u64cd\u4f5c\uff0c\u4f46\u5728\u9700\u8981\u9010\u884c\u8655\u7406\u6578\u64da\u7684\u60c5\u6cc1\u4e0b\uff0c\u5b83\u5011\u662f\u975e\u5e38\u6709\u7528\u7684\u3002<\/p>\n<pre><code>DECLARE @id INT, @name NVARCHAR(100);\nDECLARE record_cursor CURSOR FOR\nSELECT Id, Name FROM Employees;\n\nOPEN record_cursor;\nFETCH NEXT FROM record_cursor INTO @id, @name;\n\nWHILE @@FETCH_STATUS = 0\nBEGIN\n    PRINT 'ID: ' + CAST(@id AS NVARCHAR(10)) + ', Name: ' + @name;\n    FETCH NEXT FROM record_cursor INTO @id, @name;\nEND\n\nCLOSE record_cursor;\nDEALLOCATE record_cursor;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u6211\u5011\u5b9a\u7fa9\u4e86\u4e00\u500b\u6e38\u6a19\u4f86\u904d\u6b77\u540d\u70ba\u201cEmployees\u201d\u7684\u8868\u4e2d\u7684\u6240\u6709\u8a18\u9304\u3002\u6bcf\u6b21\u8fed\u4ee3\u4e2d\uff0c\u6211\u5011\u6253\u5370\u51fa\u6bcf\u500b\u54e1\u5de5\u7684ID\u548c\u59d3\u540d\u3002<\/p>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8while%e5%be%aa%e7%92%b0-gAeysGGjuH\">2. \u4f7f\u7528WHILE\u5faa\u74b0<\/h2>\n<p>\u53e6\u4e00\u7a2e\u904d\u6b77\u8868\u8a18\u9304\u7684\u65b9\u6cd5\u662f\u4f7f\u7528WHILE\u5faa\u74b0\u3002\u9019\u7a2e\u65b9\u6cd5\u901a\u5e38\u9069\u7528\u65bc\u9700\u8981\u5728\u904d\u6b77\u904e\u7a0b\u4e2d\u9032\u884c\u8a08\u7b97\u6216\u689d\u4ef6\u5224\u65b7\u7684\u60c5\u6cc1\u3002<\/p>\n<pre><code>DECLARE @count INT = 1;\nDECLARE @total INT;\n\nSELECT @total = COUNT(*) FROM Employees;\n\nWHILE @count &lt;= @total\nBEGIN\n    SELECT * FROM Employees WHERE Id = @count;\n    SET @count = @count + 1;\nEND;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u6211\u5011\u9996\u5148\u8a08\u7b97\u201cEmployees\u201d\u8868\u4e2d\u7684\u7e3d\u8a18\u9304\u6578\uff0c\u7136\u5f8c\u4f7f\u7528WHILE\u5faa\u74b0\u9010\u4e00\u67e5\u8a62\u6bcf\u689d\u8a18\u9304\u3002<\/p>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8for-xml-path-gAeysGGjuH\">3. \u4f7f\u7528FOR XML PATH<\/h2>\n<p>\u5982\u679c\u9700\u8981\u5c07\u8868\u4e2d\u7684\u6578\u64da\u4ee5\u7279\u5b9a\u683c\u5f0f\u8f38\u51fa\uff0c\u4f7f\u7528FOR XML PATH\u662f\u4e00\u500b\u975e\u5e38\u6709\u6548\u7684\u65b9\u6cd5\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u5c07\u591a\u884c\u6578\u64da\u5408\u4f75\u70ba\u4e00\u884c\uff0c\u4e26\u4ee5XML\u683c\u5f0f\u8f38\u51fa\u3002<\/p>\n<pre><code>SELECT STUFF((\n    SELECT ', ' + Name\n    FROM Employees\n    FOR XML PATH('')), 1, 2, '') AS EmployeeNames;<\/code><\/pre>\n<p>\u9019\u6bb5\u4ee3\u78bc\u5c07\u201cEmployees\u201d\u8868\u4e2d\u7684\u6240\u6709\u54e1\u5de5\u59d3\u540d\u5408\u4f75\u70ba\u4e00\u500b\u4ee5\u9017\u865f\u5206\u9694\u7684\u5b57\u7b26\u4e32\uff0c\u4e26\u8fd4\u56de\u7d50\u679c\u3002<\/p>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8cte%ef%bc%88%e5%85%ac%e7%94%a8%e8%a1%a8%e8%a1%a8%e9%81%94%e5%bc%8f%ef%bc%89-gAeysGGjuH\">4. \u4f7f\u7528CTE\uff08\u516c\u7528\u8868\u8868\u9054\u5f0f\uff09<\/h2>\n<p>\u516c\u7528\u8868\u8868\u9054\u5f0f\uff08CTE\uff09\u662f\u4e00\u7a2e\u5728SQL Server\u4e2d\u5b9a\u7fa9\u81e8\u6642\u7d50\u679c\u96c6\u7684\u65b9\u5f0f\uff0c\u53ef\u4ee5\u5728SELECT\u3001INSERT\u3001UPDATE\u6216DELETE\u8a9e\u53e5\u4e2d\u4f7f\u7528\u3002CTE\u7279\u5225\u9069\u5408\u65bc\u905e\u6b78\u67e5\u8a62\u3002<\/p>\n<pre><code>WITH EmployeeCTE AS (\n    SELECT Id, Name, ManagerId\n    FROM Employees\n    WHERE ManagerId IS NULL\n    UNION ALL\n    SELECT e.Id, e.Name, e.ManagerId\n    FROM Employees e\n    INNER JOIN EmployeeCTE cte ON e.ManagerId = cte.Id\n)\nSELECT * FROM EmployeeCTE;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u6211\u5011\u4f7f\u7528CTE\u4f86\u67e5\u8a62\u6240\u6709\u54e1\u5de5\u53ca\u5176\u7ba1\u7406\u8005\u7684\u5c64\u7d1a\u7d50\u69cb\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-gAeysGGjuH\">\u7e3d\u7d50<\/h2>\n<p>\u904d\u6b77SQL Server\u4e2d\u7684\u8868\u8a18\u9304\u6709\u591a\u7a2e\u65b9\u6cd5\uff0c\u5305\u62ec\u4f7f\u7528\u6e38\u6a19\u3001WHILE\u5faa\u74b0\u3001FOR XML PATH\u548cCTE\u7b49\u3002\u6839\u64da\u5177\u9ad4\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u6548\u7387\u548c\u9748\u6d3b\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u81f3\u95dc\u91cd\u8981\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u53ef\u9760\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u670d\u52d9\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22SQL Server\u4e2d\u904d\u6b77\u8868\u8a18\u9304\u7684\u5be6\u73fe\u65b9\u6cd5\uff0c\u5b78\u7fd2\u6709\u6548\u7684\u67e5\u8a62\u6280\u5de7\u548c\u6700\u4f73\u5be6\u8e10\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\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-138395","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138395","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=138395"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138395\/revisions"}],"predecessor-version":[{"id":138396,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138395\/revisions\/138396"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=138395"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=138395"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=138395"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}