{"id":66385,"date":"2024-10-14T17:04:17","date_gmt":"2024-10-14T09:04:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/66385\/"},"modified":"2024-10-14T17:04:17","modified_gmt":"2024-10-14T09:04:17","slug":"mssql%e4%b8%ad%e8%87%aa%e5%ae%9a%e7%be%a9%e5%ad%97%e6%ae%b5%e6%8e%92%e5%ba%8f%e7%9a%84%e5%af%a6%e7%8f%be%e6%8a%80%e5%b7%a7%ef%bc%88mssql%e8%87%aa%e5%ae%9a%e7%be%a9%e5%ad%97%e6%ae%b5%e6%8e%92%e5%ba%8f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/66385\/","title":{"rendered":"MSSQL\u4e2d\u81ea\u5b9a\u7fa9\u5b57\u6bb5\u6392\u5e8f\u7684\u5be6\u73fe\u6280\u5de7\uff08mssql\u81ea\u5b9a\u7fa9\u5b57\u6bb5\u6392\u5e8f\uff09"},"content":{"rendered":"<h1 id=\"mssql%e4%b8%ad%e8%87%aa%e5%ae%9a%e7%be%a9%e5%ad%97%e6%ae%b5%e6%8e%92%e5%ba%8f%e7%9a%84%e5%af%a6%e7%8f%be%e6%8a%80%e5%b7%a7-rGohKXWqew\">MSSQL\u4e2d\u81ea\u5b9a\u7fa9\u5b57\u6bb5\u6392\u5e8f\u7684\u5be6\u73fe\u6280\u5de7<\/h1>\n<p>\u5728\u4f7f\u7528Microsoft SQL Server\uff08MSSQL\uff09\u9032\u884c\u6578\u64da\u5eab\u7ba1\u7406\u6642\uff0c\u6392\u5e8f\u662f\u6578\u64da\u67e5\u8a62\u4e2d\u4e00\u500b\u91cd\u8981\u7684\u529f\u80fd\u3002\u9ed8\u8a8d\u60c5\u6cc1\u4e0b\uff0cMSSQL\u6703\u6839\u64da\u5b57\u6bb5\u7684\u6578\u64da\u985e\u578b\u9032\u884c\u6392\u5e8f\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u6211\u5011\u53ef\u80fd\u9700\u8981\u81ea\u5b9a\u7fa9\u6392\u5e8f\u7684\u908f\u8f2f\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5728MSSQL\u4e2d\u5be6\u73fe\u81ea\u5b9a\u7fa9\u5b57\u6bb5\u6392\u5e8f\u7684\u5e7e\u7a2e\u6280\u5de7\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8case%e8%aa%9e%e5%8f%a5%e9%80%b2%e8%a1%8c%e8%87%aa%e5%ae%9a%e7%be%a9%e6%8e%92%e5%ba%8f-rGohKXWqew\">1. \u4f7f\u7528CASE\u8a9e\u53e5\u9032\u884c\u81ea\u5b9a\u7fa9\u6392\u5e8f<\/h2>\n<p>CASE\u8a9e\u53e5\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u4f86\u5b9a\u7fa9\u6392\u5e8f\u7684\u908f\u8f2f\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u4f7f\u7528CASE\u8a9e\u53e5\u5c0d\u4e00\u500b\u540d\u70ba\u201cProducts\u201d\u7684\u8868\u9032\u884c\u81ea\u5b9a\u7fa9\u6392\u5e8f\uff1a<\/p>\n<pre><code>SELECT ProductName, Category\nFROM Products\nORDER BY \n    CASE Category\n        WHEN 'Electronics' THEN 1\n        WHEN 'Clothing' THEN 2\n        WHEN 'Books' THEN 3\n        ELSE 4\n    END;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u7522\u54c1\u5c07\u6839\u64da\u5176\u985e\u5225\u9032\u884c\u6392\u5e8f\uff0c\u96fb\u5b50\u7522\u54c1\u6392\u5728\u6700\u524d\u9762\uff0c\u7136\u5f8c\u662f\u670d\u88dd\u548c\u66f8\u7c4d\u3002<\/p>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8%e8%87%aa%e5%ae%9a%e7%be%a9%e6%8e%92%e5%ba%8f%e8%a1%a8-rGohKXWqew\">2. \u4f7f\u7528\u81ea\u5b9a\u7fa9\u6392\u5e8f\u8868<\/h2>\n<p>\u53e6\u4e00\u7a2e\u65b9\u6cd5\u662f\u5275\u5efa\u4e00\u500b\u81ea\u5b9a\u7fa9\u6392\u5e8f\u8868\uff0c\u8a72\u8868\u5305\u542b\u9700\u8981\u6392\u5e8f\u7684\u5b57\u6bb5\u53ca\u5176\u5c0d\u61c9\u7684\u6392\u5e8f\u503c\u3002\u9019\u6a23\u53ef\u4ee5\u66f4\u9748\u6d3b\u5730\u7ba1\u7406\u6392\u5e8f\u908f\u8f2f\u3002\u4ee5\u4e0b\u662f\u5275\u5efa\u81ea\u5b9a\u7fa9\u6392\u5e8f\u8868\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>CREATE TABLE CategorySort (\n    Category NVARCHAR(50),\n    SortOrder INT\n);\n\nINSERT INTO CategorySort (Category, SortOrder)\nVALUES ('Electronics', 1), ('Clothing', 2), ('Books', 3);\n<\/code><\/pre>\n<p>\u7136\u5f8c\uff0c\u53ef\u4ee5\u4f7f\u7528JOIN\u8a9e\u53e5\u5c07\u9019\u500b\u6392\u5e8f\u8868\u8207\u539f\u59cb\u6578\u64da\u8868\u9023\u63a5\uff0c\u5f9e\u800c\u5be6\u73fe\u81ea\u5b9a\u7fa9\u6392\u5e8f\uff1a<\/p>\n<pre><code>SELECT p.ProductName, c.Category\nFROM Products p\nJOIN CategorySort c ON p.Category = c.Category\nORDER BY c.SortOrder;\n<\/code><\/pre>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8order-by%e5%ad%90%e5%8f%a5%e4%b8%ad%e7%9a%84%e5%a4%9a%e5%80%8b%e5%ad%97%e6%ae%b5-rGohKXWqew\">3. \u4f7f\u7528ORDER BY\u5b50\u53e5\u4e2d\u7684\u591a\u500b\u5b57\u6bb5<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u60a8\u53ef\u80fd\u9700\u8981\u6839\u64da\u591a\u500b\u5b57\u6bb5\u9032\u884c\u6392\u5e8f\u3002\u9019\u53ef\u4ee5\u901a\u904e\u5728ORDER BY\u5b50\u53e5\u4e2d\u6307\u5b9a\u591a\u500b\u5b57\u6bb5\u4f86\u5be6\u73fe\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT ProductName, Category, Price\nFROM Products\nORDER BY Category, Price DESC;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u9996\u5148\u6839\u64da\u985e\u5225\u9032\u884c\u6392\u5e8f\uff0c\u7136\u5f8c\u5728\u6bcf\u500b\u985e\u5225\u5167\u90e8\u6839\u64da\u50f9\u683c\u9032\u884c\u964d\u5e8f\u6392\u5e8f\u3002<\/p>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8row_number%e5%87%bd%e6%95%b8-rGohKXWqew\">4. \u4f7f\u7528ROW_NUMBER()\u51fd\u6578<\/h2>\n<p>ROW_NUMBER()\u51fd\u6578\u53ef\u4ee5\u70ba\u67e5\u8a62\u7d50\u679c\u96c6\u4e2d\u7684\u6bcf\u4e00\u884c\u5206\u914d\u4e00\u500b\u552f\u4e00\u7684\u5e8f\u865f\uff0c\u9019\u5728\u9700\u8981\u9032\u884c\u8907\u96dc\u6392\u5e8f\u6642\u975e\u5e38\u6709\u7528\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff1a<\/p>\n<pre><code>WITH RankedProducts AS (\n    SELECT ProductName, Category, \n           ROW_NUMBER() OVER (PARTITION BY Category ORDER BY Price DESC) AS Rank\n    FROM Products\n)\nSELECT ProductName, Category, Rank\nFROM RankedProducts\nWHERE Rank &lt;= 5;\n<\/code><\/pre>\n<p>\u9019\u6bb5\u4ee3\u78bc\u5c07\u70ba\u6bcf\u500b\u985e\u5225\u4e2d\u7684\u7522\u54c1\u6839\u64da\u50f9\u683c\u9032\u884c\u6392\u5e8f\uff0c\u4e26\u50c5\u8fd4\u56de\u6bcf\u500b\u985e\u5225\u4e2d\u50f9\u683c\u6700\u9ad8\u7684\u524d\u4e94\u500b\u7522\u54c1\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-rGohKXWqew\">\u7e3d\u7d50<\/h2>\n<p>\u5728MSSQL\u4e2d\uff0c\u81ea\u5b9a\u7fa9\u5b57\u6bb5\u6392\u5e8f\u53ef\u4ee5\u901a\u904e\u591a\u7a2e\u65b9\u6cd5\u5be6\u73fe\uff0c\u5305\u62ec\u4f7f\u7528CASE\u8a9e\u53e5\u3001\u81ea\u5b9a\u7fa9\u6392\u5e8f\u8868\u3001ORDER BY\u5b50\u53e5\u4e2d\u7684\u591a\u500b\u5b57\u6bb5\u4ee5\u53caROW_NUMBER()\u51fd\u6578\u3002\u9019\u4e9b\u6280\u5de7\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u7684\u9748\u6d3b\u6027\uff0c\u9084\u80fd\u5e6b\u52a9\u7528\u6236\u66f4\u597d\u5730\u7ba1\u7406\u548c\u5c55\u793a\u6578\u64da\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u6258\u7ba1\u60a8\u7684MSSQL\u6578\u64da\u5eab\uff0c\u9019\u5c07\u70ba\u60a8\u7684\u696d\u52d9\u63d0\u4f9b\u7a69\u5b9a\u548c\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22MSSQL\u4e2d\u81ea\u5b9a\u7fa9\u5b57\u6bb5\u6392\u5e8f\u7684\u5be6\u73fe\u6280\u5de7\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff0c\u512a\u5316\u6578\u64da\u7ba1\u7406\uff0c\u8b93\u6578\u64da\u6392\u5e8f\u66f4\u9748\u6d3b\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-66385","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66385","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=66385"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66385\/revisions"}],"predecessor-version":[{"id":66386,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66385\/revisions\/66386"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=66385"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=66385"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=66385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}