{"id":66337,"date":"2024-10-14T16:37:25","date_gmt":"2024-10-14T08:37:25","guid":{"rendered":"https:\/\/server.hk\/cnblog\/66337\/"},"modified":"2024-10-14T16:37:25","modified_gmt":"2024-10-14T08:37:25","slug":"mssql%e4%b8%ad%e5%90%88%e4%bd%b5%e6%95%b8%e6%93%9a%e8%a1%8c%e7%9a%84%e6%8a%80%e5%b7%a7%ef%bc%88mssql%e5%90%88%e4%bd%b5%e6%95%b8%e6%93%9a%e8%a1%8c%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/66337\/","title":{"rendered":"MSSQL\u4e2d\u5408\u4f75\u6578\u64da\u884c\u7684\u6280\u5de7\uff08mssql\u5408\u4f75\u6578\u64da\u884c\uff09"},"content":{"rendered":"<h1 id=\"mssql%e4%b8%ad%e5%90%88%e4%bd%b5%e6%95%b8%e6%93%9a%e8%a1%8c%e7%9a%84%e6%8a%80%e5%b7%a7%ef%bc%88mssql%e5%90%88%e4%bd%b5%e6%95%b8%e6%93%9a%e8%a1%8c%ef%bc%89-PObuGRQUok\">MSSQL\u4e2d\u5408\u4f75\u6578\u64da\u884c\u7684\u6280\u5de7\uff08MSSQL\u5408\u4f75\u6578\u64da\u884c\uff09<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5408\u4f75\u6578\u64da\u884c\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u91cd\u8907\u6578\u64da\u6216\u9700\u8981\u5c07\u591a\u884c\u6578\u64da\u6574\u5408\u70ba\u4e00\u884c\u7684\u60c5\u6cc1\u4e0b\u3002Microsoft SQL Server\uff08MSSQL\uff09\u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u5be6\u73fe\u9019\u4e00\u76ee\u6a19\uff0c\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u6709\u6548\u7684\u6280\u5de7\u548c\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8group-by%e8%aa%9e%e5%8f%a5-PObuGRQUok\">1. \u4f7f\u7528GROUP BY\u8a9e\u53e5<\/h2>\n<p>\u6700\u5e38\u898b\u7684\u5408\u4f75\u6578\u64da\u884c\u7684\u65b9\u6cd5\u662f\u4f7f\u7528<code>GROUP BY<\/code>\u8a9e\u53e5\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u6839\u64da\u7279\u5b9a\u7684\u5217\u5c07\u6578\u64da\u5206\u7d44\uff0c\u4e26\u5c0d\u6bcf\u7d44\u6578\u64da\u9032\u884c\u805a\u5408\u64cd\u4f5c\u3002<\/p>\n<pre><code>SELECT \n    CustomerID, \n    COUNT(OrderID) AS TotalOrders, \n    SUM(OrderAmount) AS TotalAmount\nFROM \n    Orders\nGROUP BY \n    CustomerID;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u6839\u64da<code>CustomerID<\/code>\u5c0d\u8a02\u55ae\u9032\u884c\u5206\u7d44\uff0c\u4e26\u8a08\u7b97\u6bcf\u4f4d\u5ba2\u6236\u7684\u8a02\u55ae\u6578\u91cf\u548c\u7e3d\u91d1\u984d\u3002<\/p>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8string_agg%e5%87%bd%e6%95%b8-PObuGRQUok\">2. \u4f7f\u7528STRING_AGG\u51fd\u6578<\/h2>\n<p>\u5728SQL Server 2017\u53ca\u4ee5\u5f8c\u7684\u7248\u672c\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528<code>STRING_AGG<\/code>\u51fd\u6578\u4f86\u5408\u4f75\u5b57\u7b26\u4e32\u6578\u64da\u3002\u9019\u5c0d\u65bc\u9700\u8981\u5c07\u591a\u884c\u6587\u672c\u5408\u4f75\u70ba\u4e00\u884c\u7684\u60c5\u6cc1\u7279\u5225\u6709\u7528\u3002<\/p>\n<pre><code>SELECT \n    CustomerID, \n    STRING_AGG(ProductName, ', ') AS Products\nFROM \n    OrderDetails\nGROUP BY \n    CustomerID;\n<\/code><\/pre>\n<p>\u9019\u6bb5\u4ee3\u78bc\u5c07\u6bcf\u4f4d\u5ba2\u6236\u7684\u7522\u54c1\u540d\u7a31\u5408\u4f75\u70ba\u4e00\u500b\u4ee5\u9017\u865f\u5206\u9694\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8for-xml-path-PObuGRQUok\">3. \u4f7f\u7528FOR XML PATH<\/h2>\n<p>\u5c0d\u65bc\u65e9\u671f\u7248\u672c\u7684SQL Server\uff0c<code>FOR XML PATH<\/code>\u662f\u4e00\u500b\u5e38\u7528\u7684\u6280\u5de7\u4f86\u5408\u4f75\u884c\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u751f\u6210XML\u683c\u5f0f\u7684\u5b57\u7b26\u4e32\uff0c\u4e26\u5c07\u5176\u8f49\u63db\u70ba\u6240\u9700\u7684\u683c\u5f0f\u3002<\/p>\n<pre><code>SELECT \n    CustomerID, \n    STUFF((SELECT ', ' + ProductName \n           FROM OrderDetails \n           WHERE OrderID = o.OrderID \n           FOR XML PATH('')), 1, 2, '') AS Products\nFROM \n    Orders o\nGROUP BY \n    CustomerID;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u4f7f\u7528<code>STUFF<\/code>\u51fd\u6578\u4f86\u53bb\u9664\u958b\u982d\u7684\u9017\u865f\uff0c\u6700\u7d42\u751f\u6210\u6bcf\u4f4d\u5ba2\u6236\u7684\u7522\u54c1\u5217\u8868\u3002<\/p>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8cte%ef%bc%88%e5%85%ac%e7%94%a8%e8%a1%a8%e9%81%94%e5%bc%8f%ef%bc%89-PObuGRQUok\">4. \u4f7f\u7528CTE\uff08\u516c\u7528\u8868\u9054\u5f0f\uff09<\/h2>\n<p>\u516c\u7528\u8868\u9054\u5f0f\uff08CTE\uff09\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u5728\u5408\u4f75\u6578\u64da\u884c\u6642\u63d0\u9ad8\u53ef\u8b80\u6027\u548c\u7dad\u8b77\u6027\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528CTE\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>WITH ProductList AS (\n    SELECT \n        CustomerID, \n        ProductName\n    FROM \n        OrderDetails\n)\nSELECT \n    CustomerID, \n    STRING_AGG(ProductName, ', ') AS Products\nFROM \n    ProductList\nGROUP BY \n    CustomerID;\n<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u5beb\u6cd5\u4f7f\u5f97\u67e5\u8a62\u7d50\u69cb\u66f4\u52a0\u6e05\u6670\uff0c\u4fbf\u65bc\u7406\u89e3\u548c\u7dad\u8b77\u3002<\/p>\n<h2 id=\"5-%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-PObuGRQUok\">5. \u6ce8\u610f\u4e8b\u9805<\/h2>\n<ul>\n<li>\u5728\u5408\u4f75\u6578\u64da\u884c\u6642\uff0c\u78ba\u4fdd\u9078\u64c7\u5408\u9069\u7684\u805a\u5408\u51fd\u6578\uff0c\u4ee5\u907f\u514d\u6578\u64da\u4e1f\u5931\u6216\u932f\u8aa4\u3002<\/li>\n<li>\u5c0d\u65bc\u5927\u578b\u6578\u64da\u96c6\uff0c\u5408\u4f75\u64cd\u4f5c\u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\uff0c\u5efa\u8b70\u5728\u9032\u884c\u5408\u4f75\u524d\u9032\u884c\u6027\u80fd\u6e2c\u8a66\u3002<\/li>\n<li>\u5728\u4f7f\u7528<code>FOR XML PATH<\/code>\u6642\uff0c\u6ce8\u610f\u8655\u7406\u7279\u6b8a\u5b57\u7b26\uff0c\u4ee5\u907f\u514d\u751f\u6210\u7121\u6548\u7684XML\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-PObuGRQUok\">\u7e3d\u7d50<\/h2>\n<p>\u5408\u4f75\u6578\u64da\u884c\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u662f\u4e00\u9805\u91cd\u8981\u7684\u6280\u80fd\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u66f4\u6709\u6548\u5730\u5206\u6790\u548c\u5831\u544a\u6578\u64da\u3002\u7121\u8ad6\u662f\u4f7f\u7528<code>GROUP BY<\/code>\u3001<code>STRING_AGG<\/code>\u9084\u662f<code>FOR XML PATH<\/code>\uff0c\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\u53d6\u6c7a\u65bc\u5177\u9ad4\u7684\u9700\u6c42\u548c\u6578\u64da\u7d50\u69cb\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u7ba1\u7406\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u64cd\u4f5c\uff0c\u63d0\u4f9b\u7a69\u5b9a\u548c\u9748\u6d3b\u7684\u74b0\u5883\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22MSSQL\u4e2d\u5408\u4f75\u6578\u64da\u884c\u7684\u6280\u5de7\uff0c\u5b78\u7fd2\u5982\u4f55\u6709\u6548\u6574\u5408\u6578\u64da\u4ee5\u63d0\u5347\u67e5\u8a62\u6548\u7387\u548c\u6578\u64da\u7ba1\u7406\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-66337","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66337","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=66337"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66337\/revisions"}],"predecessor-version":[{"id":66338,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66337\/revisions\/66338"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=66337"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=66337"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=66337"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}