{"id":159981,"date":"2024-11-03T19:17:22","date_gmt":"2024-11-03T11:17:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/159981\/"},"modified":"2024-11-03T19:17:23","modified_gmt":"2024-11-03T11:17:23","slug":"mssql-%e6%95%99%e7%a8%8b-sql-first-%e5%87%bd%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/159981\/","title":{"rendered":"MSSQL \u6559\u7a0b SQL FIRST() \u51fd\u6578"},"content":{"rendered":"<h1 id=\"mssql-%e6%95%99%e7%a8%8b-sql-first-%e5%87%bd%e6%95%b8-glypaGMFuQ\">MSSQL \u6559\u7a0b SQL FIRST() \u51fd\u6578<\/h1>\n<p>\u5728 Microsoft SQL Server \u4e2d\uff0c<code>FIRST()<\/code> \u51fd\u6578\u662f\u4e00\u500b\u975e\u5e38\u6709\u7528\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u5f9e\u67e5\u8a62\u7d50\u679c\u4e2d\u7372\u53d6\u7b2c\u4e00\u500b\u503c\u3002\u96d6\u7136 SQL Server \u672c\u8eab\u4e26\u4e0d\u76f4\u63a5\u63d0\u4f9b <code>FIRST()<\/code> \u51fd\u6578\uff0c\u4f46\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u5176\u4ed6 SQL \u51fd\u6578\u4f86\u9054\u5230\u76f8\u4f3c\u7684\u6548\u679c\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u5982\u4f55\u5728 MSSQL \u4e2d\u6a21\u64ec <code>FIRST()<\/code> \u51fd\u6578\u7684\u529f\u80fd\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u7bc4\u4f8b\u3002<\/p>\n<h2 id=\"%e7%90%86%e8%a7%a3-first-%e5%87%bd%e6%95%b8%e7%9a%84%e6%a6%82%e5%bf%b5-glypaGMFuQ\">\u7406\u89e3 FIRST() \u51fd\u6578\u7684\u6982\u5ff5<\/h2>\n<p><code>FIRST()<\/code> \u51fd\u6578\u7684\u4e3b\u8981\u76ee\u7684\u662f\u5f9e\u4e00\u7d44\u6578\u64da\u4e2d\u8fd4\u56de\u7b2c\u4e00\u500b\u503c\u3002\u5728 SQL \u67e5\u8a62\u4e2d\uff0c\u9019\u901a\u5e38\u662f\u6307\u5728\u67d0\u500b\u6392\u5e8f\u689d\u4ef6\u4e0b\u7684\u7b2c\u4e00\u884c\u6578\u64da\u3002\u96d6\u7136 SQL Server \u6c92\u6709\u5167\u5efa\u7684 <code>FIRST()<\/code> \u51fd\u6578\uff0c\u4f46\u6211\u5011\u53ef\u4ee5\u4f7f\u7528 <code>TOP<\/code> \u548c <code>ORDER BY<\/code> \u5b50\u53e5\u4f86\u5be6\u73fe\u76f8\u540c\u7684\u6548\u679c\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-top-%e5%92%8c-order-by-%e6%a8%a1%e6%93%ac-first-%e5%87%bd%e6%95%b8-glypaGMFuQ\">\u4f7f\u7528 TOP \u548c ORDER BY \u6a21\u64ec FIRST() \u51fd\u6578<\/h2>\n<p>\u8981\u7372\u53d6\u67e5\u8a62\u7d50\u679c\u4e2d\u7684\u7b2c\u4e00\u500b\u503c\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528 <code>SELECT TOP 1<\/code> \u8a9e\u53e5\uff0c\u4e26\u7d50\u5408 <code>ORDER BY<\/code> \u4f86\u6307\u5b9a\u6392\u5e8f\u689d\u4ef6\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u7bc4\u4f8b\uff1a<\/p>\n<pre><code>SELECT TOP 1 column_name\nFROM table_name\nORDER BY column_name ASC;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c<code>column_name<\/code> \u662f\u6211\u5011\u60f3\u8981\u7372\u53d6\u7684\u5217\u540d\uff0c\u800c <code>table_name<\/code> \u662f\u6578\u64da\u8868\u7684\u540d\u7a31\u3002<code>ORDER BY column_name ASC<\/code> \u5c07\u6578\u64da\u6309\u5347\u5e8f\u6392\u5217\uff0c\u7136\u5f8c <code>TOP 1<\/code> \u5c07\u8fd4\u56de\u7b2c\u4e00\u884c\u7684\u6578\u64da\u3002<\/p>\n<h2 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e7%8d%b2%e5%8f%96%e7%ac%ac%e4%b8%80%e5%80%8b%e8%a8%82%e5%96%ae%e7%9a%84%e5%ae%a2%e6%88%b6%e5%90%8d%e7%a8%b1-glypaGMFuQ\">\u7bc4\u4f8b\uff1a\u7372\u53d6\u7b2c\u4e00\u500b\u8a02\u55ae\u7684\u5ba2\u6236\u540d\u7a31<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>Orders<\/code> \u7684\u8868\uff0c\u5305\u542b\u4ee5\u4e0b\u5217\uff1a<code>OrderID<\/code>\u3001<code>CustomerName<\/code> \u548c <code>OrderDate<\/code>\u3002\u6211\u5011\u60f3\u8981\u7372\u53d6\u6700\u65e9\u7684\u8a02\u55ae\u7684\u5ba2\u6236\u540d\u7a31\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT TOP 1 CustomerName\nFROM Orders\nORDER BY OrderDate ASC;\n<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6700\u65e9\u8a02\u55ae\u7684\u5ba2\u6236\u540d\u7a31\uff0c\u56e0\u70ba\u6211\u5011\u6309\u7167 <code>OrderDate<\/code> \u5347\u5e8f\u6392\u5217\uff0c\u4e26\u9078\u64c7\u4e86\u7b2c\u4e00\u884c\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%aa%97%e5%8f%a3%e5%87%bd%e6%95%b8%e7%8d%b2%e5%8f%96%e7%ac%ac%e4%b8%80%e5%80%8b%e5%80%bc-glypaGMFuQ\">\u4f7f\u7528\u7a97\u53e3\u51fd\u6578\u7372\u53d6\u7b2c\u4e00\u500b\u503c<\/h2>\n<p>\u9664\u4e86\u4f7f\u7528 <code>TOP<\/code> \u548c <code>ORDER BY<\/code>\uff0c\u6211\u5011\u9084\u53ef\u4ee5\u4f7f\u7528\u7a97\u53e3\u51fd\u6578\u4f86\u7372\u53d6\u7b2c\u4e00\u500b\u503c\u3002\u9019\u5728\u9700\u8981\u5c0d\u5206\u7d44\u6578\u64da\u9032\u884c\u64cd\u4f5c\u6642\u7279\u5225\u6709\u7528\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528\u7a97\u53e3\u51fd\u6578\u7684\u7bc4\u4f8b\uff1a<\/p>\n<pre><code>SELECT CustomerName,\n       ROW_NUMBER() OVER (PARTITION BY CustomerID ORDER BY OrderDate ASC) AS RowNum\nFROM Orders\nWHERE RowNum = 1;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u4f7f\u7528 <code>ROW_NUMBER()<\/code> \u51fd\u6578\u70ba\u6bcf\u500b\u5ba2\u6236\u7684\u8a02\u55ae\u5206\u914d\u4e00\u500b\u884c\u865f\uff0c\u7136\u5f8c\u9078\u64c7\u884c\u865f\u70ba 1 \u7684\u8a02\u55ae\uff0c\u9019\u6a23\u5c31\u80fd\u7372\u5f97\u6bcf\u500b\u5ba2\u6236\u7684\u7b2c\u4e00\u500b\u8a02\u55ae\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-glypaGMFuQ\">\u7e3d\u7d50<\/h2>\n<p>\u96d6\u7136 SQL Server \u6c92\u6709\u76f4\u63a5\u7684 <code>FIRST()<\/code> \u51fd\u6578\uff0c\u4f46\u6211\u5011\u53ef\u4ee5\u901a\u904e\u4f7f\u7528 <code>TOP<\/code> \u548c <code>ORDER BY<\/code> \u4f86\u8f15\u9b06\u7372\u53d6\u67e5\u8a62\u7d50\u679c\u4e2d\u7684\u7b2c\u4e00\u500b\u503c\u3002\u6b64\u5916\uff0c\u7a97\u53e3\u51fd\u6578\u4e5f\u63d0\u4f9b\u4e86\u66f4\u9748\u6d3b\u7684\u65b9\u5f0f\u4f86\u8655\u7406\u5206\u7d44\u6578\u64da\u3002\u9019\u4e9b\u6280\u8853\u5c0d\u65bc\u6578\u64da\u5206\u6790\u548c\u5831\u544a\u751f\u6210\u975e\u5e38\u91cd\u8981\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u904b\u884c\u60a8\u7684 MSSQL \u6578\u64da\u5eab\uff0cServer.HK \u63d0\u4f9b\u4e86\u591a\u7a2e\u9078\u64c7\uff0c\u9069\u5408\u5404\u7a2e\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f\u5176\u4ed6\u5730\u5340\u7684\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3 MSSQL \u6559\u7a0b\u4e2d\u7684 SQL FIRST() \u51fd\u6578\uff0c\u5b78\u7fd2\u5982\u4f55\u7372\u53d6\u67e5\u8a62\u7d50\u679c\u4e2d\u7684\u7b2c\u4e00\u500b\u503c\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-159981","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/159981","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=159981"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/159981\/revisions"}],"predecessor-version":[{"id":159982,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/159981\/revisions\/159982"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=159981"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=159981"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=159981"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}