{"id":96254,"date":"2024-10-20T07:53:16","date_gmt":"2024-10-19T23:53:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96254\/"},"modified":"2024-10-20T07:53:16","modified_gmt":"2024-10-19T23:53:16","slug":"oracle%e4%b8%ad%e7%9a%84rownum%e7%b8%bd%e7%b5%90","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96254\/","title":{"rendered":"Oracle\u4e2d\u7684rownum\u7e3d\u7d50"},"content":{"rendered":"<h1 id=\"oracle%e4%b8%ad%e7%9a%84rownum%e7%b8%bd%e7%b5%90-cnJXmJVZqH\">Oracle\u4e2d\u7684rownum\u7e3d\u7d50<\/h1>\n<p>\u5728Oracle\u6578\u64da\u5eab\u4e2d\uff0c<code>rownum<\/code>\u662f\u4e00\u500b\u975e\u5e38\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u5c24\u5176\u662f\u5728\u8655\u7406\u67e5\u8a62\u7d50\u679c\u6642\u3002\u5b83\u662f\u4e00\u500b\u865b\u64ec\u7684\u5217\uff0c\u8868\u793a\u67e5\u8a62\u7d50\u679c\u96c6\u4e2d\u6bcf\u4e00\u884c\u7684\u5e8f\u865f\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0e<code>rownum<\/code>\u7684\u4f7f\u7528\u65b9\u6cd5\u3001\u7279\u6027\u4ee5\u53ca\u4e00\u4e9b\u5e38\u898b\u7684\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"rownum%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-cnJXmJVZqH\">rownum\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u5728Oracle\u4e2d\uff0c<code>rownum<\/code>\u662f\u5f9e1\u958b\u59cb\u7684\u6574\u6578\uff0c\u8868\u793a\u67e5\u8a62\u7d50\u679c\u4e2d\u6bcf\u4e00\u884c\u7684\u9806\u5e8f\u3002\u7576\u57f7\u884c\u67e5\u8a62\u6642\uff0cOracle\u6703\u5728\u8fd4\u56de\u7d50\u679c\u4e4b\u524d\u70ba\u6bcf\u4e00\u884c\u5206\u914d\u4e00\u500b<code>rownum<\/code>\u503c\u3002\u9019\u610f\u5473\u8457<code>rownum<\/code>\u7684\u503c\u662f\u6839\u64da\u884c\u7684\u8fd4\u56de\u9806\u5e8f\u800c\u5b9a\u7684\uff0c\u800c\u4e0d\u662f\u6839\u64da\u6578\u64da\u7684\u7269\u7406\u5b58\u5132\u9806\u5e8f\u3002<\/p>\n<h2 id=\"rownum%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95-cnJXmJVZqH\">rownum\u7684\u4f7f\u7528\u65b9\u6cd5<\/h2>\n<p>\u4f7f\u7528<code>rownum<\/code>\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT * FROM table_name WHERE ROWNUM &lt;= n;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u8868\u4e2d\u524dn\u884c\u7684\u6578\u64da\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u60f3\u8981\u5f9e\u4e00\u500b\u540d\u70ba<code>employees<\/code>\u7684\u8868\u4e2d\u7372\u53d6\u524d5\u540d\u54e1\u5de5\u7684\u8cc7\u6599\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT * FROM employees WHERE ROWNUM &lt;= 5;<\/code><\/pre>\n<h2 id=\"rownum%e7%9a%84%e7%89%b9%e6%80%a7-cnJXmJVZqH\">rownum\u7684\u7279\u6027<\/h2>\n<ul>\n<li><strong>\u884c\u865f\u7684\u5206\u914d\uff1a<\/strong>\u5728\u67e5\u8a62\u57f7\u884c\u904e\u7a0b\u4e2d\uff0c<code>rownum<\/code>\u7684\u503c\u662f\u6839\u64da\u884c\u7684\u8fd4\u56de\u9806\u5e8f\u5206\u914d\u7684\u3002\u56e0\u6b64\uff0c<code>rownum<\/code>\u7684\u503c\u5728\u67e5\u8a62\u7684\u4e0d\u540c\u57f7\u884c\u4e2d\u53ef\u80fd\u6703\u6709\u6240\u4e0d\u540c\u3002<\/li>\n<li><strong>\u904e\u6ffe\u689d\u4ef6\u7684\u5f71\u97ff\uff1a<\/strong>\u5982\u679c\u5728<code>WHERE<\/code>\u5b50\u53e5\u4e2d\u4f7f\u7528<code>rownum<\/code>\uff0c\u5247\u5fc5\u9808\u6ce8\u610f\u904e\u6ffe\u689d\u4ef6\u7684\u9806\u5e8f\u3002<code>rownum<\/code>\u7684\u503c\u662f\u5728<code>WHERE<\/code>\u5b50\u53e5\u8a55\u4f30\u4e4b\u524d\u5206\u914d\u7684\u3002<\/li>\n<li><strong>\u8207ORDER BY\u7684\u7d50\u5408\uff1a<\/strong>\u5982\u679c\u9700\u8981\u6839\u64da\u67d0\u500b\u5217\u7684\u503c\u9032\u884c\u6392\u5e8f\u4e26\u9650\u5236\u8fd4\u56de\u7684\u884c\u6578\uff0c\u5247\u9700\u8981\u4f7f\u7528\u5b50\u67e5\u8a62\u3002\u4f8b\u5982\uff1a<\/strong><\/li>\n<\/ul>\n<pre><code>SELECT * FROM (SELECT * FROM employees ORDER BY salary DESC) WHERE ROWNUM &lt;= 5;<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u67e5\u8a62\u5c07\u9996\u5148\u6839\u64da\u85aa\u6c34\u964d\u5e8f\u6392\u5217\u6240\u6709\u54e1\u5de5\uff0c\u7136\u5f8c\u8fd4\u56de\u524d5\u540d\u85aa\u6c34\u6700\u9ad8\u7684\u54e1\u5de5\u3002<\/p>\n<h2 id=\"%e5%b8%b8%e8%a6%8b%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-cnJXmJVZqH\">\u5e38\u898b\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528<code>rownum<\/code>\u7684\u5e38\u898b\u5834\u666f\uff1a<\/p>\n<ul>\n<li><strong>\u9650\u5236\u67e5\u8a62\u7d50\u679c\uff1a<\/strong>\u7576\u9700\u8981\u5f9e\u5927\u578b\u6578\u64da\u96c6\u4e2d\u7372\u53d6\u524d\u5e7e\u884c\u6642\uff0c<code>rownum<\/code>\u975e\u5e38\u6709\u7528\u3002<\/li>\n<li><strong>\u5206\u9801\u67e5\u8a62\uff1a<\/strong>\u5728\u5be6\u73fe\u5206\u9801\u529f\u80fd\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528<code>rownum<\/code>\u4f86\u9650\u5236\u6bcf\u9801\u986f\u793a\u7684\u884c\u6578\u3002<\/li>\n<li><strong>\u6578\u64da\u62bd\u6a23\uff1a<\/strong>\u5728\u9032\u884c\u6578\u64da\u5206\u6790\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528<code>rownum<\/code>\u4f86\u96a8\u6a5f\u62bd\u53d6\u90e8\u5206\u6578\u64da\u9032\u884c\u5206\u6790\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-cnJXmJVZqH\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u4f7f\u7528<code>rownum<\/code>\u6642\uff0c\u6709\u5e7e\u9ede\u9700\u8981\u7279\u5225\u6ce8\u610f\uff1a<\/p>\n<ul>\n<li>\u5728\u4f7f\u7528<code>rownum<\/code>\u9032\u884c\u904e\u6ffe\u6642\uff0c\u5fc5\u9808\u78ba\u4fdd\u904e\u6ffe\u689d\u4ef6\u7684\u6b63\u78ba\u6027\uff0c\u4ee5\u907f\u514d\u610f\u5916\u7684\u7d50\u679c\u3002<\/li>\n<li>\u5728\u9032\u884c\u6392\u5e8f\u6642\uff0c\u61c9\u4f7f\u7528\u5b50\u67e5\u8a62\u4f86\u78ba\u4fdd<code>rownum<\/code>\u7684\u6b63\u78ba\u6027\u3002<\/li>\n<li>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528<code>rownum<\/code>\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u554f\u984c\uff0c\u56e0\u6b64\u5728\u8655\u7406\u5927\u578b\u6578\u64da\u96c6\u6642\u61c9\u8b39\u614e\u4f7f\u7528\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-cnJXmJVZqH\">\u7e3d\u7d50<\/h2>\n<p>\u7e3d\u7684\u4f86\u8aaa\uff0c<code>rownum<\/code>\u5728Oracle\u4e2d\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u6709\u6548\u5730\u7ba1\u7406\u67e5\u8a62\u7d50\u679c\u3002\u7121\u8ad6\u662f\u9650\u5236\u67e5\u8a62\u7d50\u679c\u3001\u5be6\u73fe\u5206\u9801\u529f\u80fd\uff0c\u9084\u662f\u9032\u884c\u6578\u64da\u62bd\u6a23\uff0c<code>rownum<\/code>\u90fd\u80fd\u63d0\u4f9b\u4fbf\u5229\u3002\u7136\u800c\uff0c\u5728\u4f7f\u7528\u6642\u9700\u8981\u6ce8\u610f\u5176\u7279\u6027\u548c\u9650\u5236\uff0c\u4ee5\u78ba\u4fdd\u67e5\u8a62\u7684\u6e96\u78ba\u6027\u548c\u6027\u80fd\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc<code>VPS<\/code>\u3001<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u3001<code>\u670d\u52a1\u5668<\/code>\u6216\u5176\u4ed6\u76f8\u95dc\u4e3b\u984c\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u8cc7\u8a0a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3Oracle\u4e2d\u7684rownum\u7528\u6cd5\uff0c\u638c\u63e1\u5982\u4f55\u6709\u6548\u9650\u5236\u67e5\u8a62\u7d50\u679c\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-96254","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96254","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=96254"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96254\/revisions"}],"predecessor-version":[{"id":96255,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96254\/revisions\/96255"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96254"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96254"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96254"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}