{"id":143897,"date":"2024-11-01T02:10:20","date_gmt":"2024-10-31T18:10:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/143897\/"},"modified":"2024-11-01T02:10:21","modified_gmt":"2024-10-31T18:10:21","slug":"sql-%e5%88%aa%e9%99%a4%e9%87%8d%e8%a4%87%e8%a8%98%e9%8c%84%e7%9a%84%e5%9b%9b%e7%a8%ae%e6%96%b9%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/143897\/","title":{"rendered":"SQL \u522a\u9664\u91cd\u8907\u8a18\u9304\u7684\u56db\u7a2e\u65b9\u5f0f"},"content":{"rendered":"<h1 id=\"sql-%e5%88%aa%e9%99%a4%e9%87%8d%e8%a4%87%e8%a8%98%e9%8c%84%e7%9a%84%e5%9b%9b%e7%a8%ae%e6%96%b9%e5%bc%8f-cDZsFOLWUU\">SQL \u522a\u9664\u91cd\u8907\u8a18\u9304\u7684\u56db\u7a2e\u65b9\u5f0f<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u91cd\u8907\u8a18\u9304\u662f\u4e00\u500b\u5e38\u898b\u7684\u554f\u984c\uff0c\u9019\u4e0d\u50c5\u6703\u5f71\u97ff\u6578\u64da\u7684\u6e96\u78ba\u6027\uff0c\u9084\u53ef\u80fd\u5c0e\u81f4\u67e5\u8a62\u6548\u7387\u7684\u4e0b\u964d\u3002\u70ba\u4e86\u4fdd\u6301\u6578\u64da\u7684\u6574\u6f54\u6027\u548c\u4e00\u81f4\u6027\uff0c\u522a\u9664\u91cd\u8907\u8a18\u9304\u662f\u5fc5\u8981\u7684\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u56db\u7a2e\u5728 SQL \u4e2d\u522a\u9664\u91cd\u8907\u8a18\u9304\u7684\u65b9\u6cd5\uff0c\u5e6b\u52a9\u60a8\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u3002<\/p>\n<h2 id=\"%e6%96%b9%e6%b3%95%e4%b8%80%ef%bc%9a%e4%bd%bf%e7%94%a8-cte-%e5%92%8c-row_number-cDZsFOLWUU\">\u65b9\u6cd5\u4e00\uff1a\u4f7f\u7528 CTE \u548c ROW_NUMBER()<\/h2>\n<p>\u516c\u5171\u8868\u8868\u9054\u5f0f\uff08CTE\uff09\u7d50\u5408 ROW_NUMBER() \u51fd\u6578\u662f\u4e00\u7a2e\u5e38\u898b\u7684\u522a\u9664\u91cd\u8907\u8a18\u9304\u7684\u65b9\u6cd5\u3002\u9019\u7a2e\u65b9\u6cd5\u901a\u904e\u70ba\u6bcf\u4e00\u7d44\u91cd\u8907\u8a18\u9304\u5206\u914d\u4e00\u500b\u552f\u4e00\u7684\u884c\u865f\uff0c\u7136\u5f8c\u522a\u9664\u884c\u865f\u5927\u65bc 1 \u7684\u8a18\u9304\u3002<\/p>\n<pre><code>WITH CTE AS (\n    SELECT *,\n           ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY (SELECT NULL)) AS rn\n    FROM your_table\n)\nDELETE FROM CTE WHERE rn &gt; 1;<\/code><\/pre>\n<p>\u5728\u9019\u6bb5\u4ee3\u78bc\u4e2d\uff0c\u60a8\u9700\u8981\u5c07 <code>column1<\/code> \u548c <code>column2<\/code> \u66ff\u63db\u70ba\u60a8\u8981\u6aa2\u67e5\u91cd\u8907\u7684\u5217\u540d\uff0c<code>your_table<\/code> \u66ff\u63db\u70ba\u60a8\u7684\u8868\u540d\u3002<\/p>\n<h2 id=\"%e6%96%b9%e6%b3%95%e4%ba%8c%ef%bc%9a%e4%bd%bf%e7%94%a8-group-by-%e5%92%8c-having-cDZsFOLWUU\">\u65b9\u6cd5\u4e8c\uff1a\u4f7f\u7528 GROUP BY \u548c HAVING<\/h2>\n<p>\u53e6\u4e00\u7a2e\u65b9\u6cd5\u662f\u4f7f\u7528 <code>GROUP BY<\/code> \u548c <code>HAVING<\/code> \u5b50\u53e5\u4f86\u8b58\u5225\u91cd\u8907\u8a18\u9304\uff0c\u7136\u5f8c\u522a\u9664\u5b83\u5011\u3002\u9019\u7a2e\u65b9\u6cd5\u901a\u5e38\u9069\u7528\u65bc\u9700\u8981\u4fdd\u7559\u67d0\u4e00\u7d44\u8a18\u9304\u7684\u60c5\u6cc1\u3002<\/p>\n<pre><code>DELETE FROM your_table\nWHERE id NOT IN (\n    SELECT MIN(id)\n    FROM your_table\n    GROUP BY column1, column2\n);<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>id<\/code> \u662f\u8868\u4e2d\u7684\u4e3b\u9375\uff0c\u60a8\u9700\u8981\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u8abf\u6574 <code>column1<\/code> \u548c <code>column2<\/code>\u3002<\/p>\n<h2 id=\"%e6%96%b9%e6%b3%95%e4%b8%89%ef%bc%9a%e4%bd%bf%e7%94%a8-distinct-%e5%92%8c-insert-into-cDZsFOLWUU\">\u65b9\u6cd5\u4e09\uff1a\u4f7f\u7528 DISTINCT \u548c INSERT INTO<\/h2>\n<p>\u5982\u679c\u60a8\u5e0c\u671b\u4fdd\u7559\u539f\u59cb\u8868\u7684\u6578\u64da\u4e26\u5275\u5efa\u4e00\u500b\u65b0\u8868\u4f86\u5b58\u5132\u552f\u4e00\u8a18\u9304\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>DISTINCT<\/code> \u95dc\u9375\u5b57\u548c <code>INSERT INTO<\/code> \u8a9e\u53e5\u3002<\/p>\n<pre><code>CREATE TABLE new_table AS\nSELECT DISTINCT *\nFROM your_table;<\/code><\/pre>\n<p>\u9019\u6a23\u6703\u5275\u5efa\u4e00\u500b\u540d\u70ba <code>new_table<\/code> \u7684\u65b0\u8868\uff0c\u4e26\u5c07\u6240\u6709\u552f\u4e00\u7684\u8a18\u9304\u63d2\u5165\u5176\u4e2d\u3002\u7136\u5f8c\uff0c\u60a8\u53ef\u4ee5\u9078\u64c7\u522a\u9664\u539f\u59cb\u8868\u6216\u4fdd\u7559\u5b83\u3002<\/p>\n<h2 id=\"%e6%96%b9%e6%b3%95%e5%9b%9b%ef%bc%9a%e4%bd%bf%e7%94%a8%e8%87%aa%e9%80%a3%e6%8e%a5-cDZsFOLWUU\">\u65b9\u6cd5\u56db\uff1a\u4f7f\u7528\u81ea\u9023\u63a5<\/h2>\n<p>\u81ea\u9023\u63a5\u662f\u4e00\u7a2e\u901a\u904e\u5c07\u8868\u8207\u81ea\u8eab\u9032\u884c\u6bd4\u8f03\u4f86\u522a\u9664\u91cd\u8907\u8a18\u9304\u7684\u65b9\u6cd5\u3002\u9019\u7a2e\u65b9\u6cd5\u9069\u5408\u65bc\u9700\u8981\u66f4\u8907\u96dc\u689d\u4ef6\u7684\u60c5\u6cc1\u3002<\/p>\n<pre><code>DELETE a\nFROM your_table a\nINNER JOIN your_table b\nON a.column1 = b.column1 AND a.column2 = b.column2\nWHERE a.id &gt; b.id;<\/code><\/pre>\n<p>\u5728\u9019\u6bb5\u4ee3\u78bc\u4e2d\uff0c\u60a8\u9700\u8981\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u66ff\u63db <code>column1<\/code> \u548c <code>column2<\/code>\uff0c\u4e26\u78ba\u4fdd <code>id<\/code> \u662f\u552f\u4e00\u6a19\u8b58\u7b26\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-cDZsFOLWUU\">\u7e3d\u7d50<\/h2>\n<p>\u5728 SQL \u4e2d\u522a\u9664\u91cd\u8907\u8a18\u9304\u7684\u65b9\u6cd5\u6709\u5f88\u591a\uff0c\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\u53d6\u6c7a\u65bc\u5177\u9ad4\u7684\u9700\u6c42\u548c\u6578\u64da\u7d50\u69cb\u3002\u7121\u8ad6\u662f\u4f7f\u7528 CTE\u3001GROUP BY\u3001DISTINCT \u9084\u662f\u81ea\u9023\u63a5\uff0c\u4e86\u89e3\u9019\u4e9b\u6280\u8853\u90fd\u80fd\u5e6b\u52a9\u60a8\u66f4\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u4f01\u696d\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u900f\u904e <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u63d0\u4f9b\u7684\u7a69\u5b9a\u6027\u548c\u9748\u6d3b\u6027\uff0c\u60a8\u53ef\u4ee5\u66f4\u597d\u5730\u61c9\u5c0d\u6578\u64da\u7ba1\u7406\u7684\u6311\u6230\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22\u56db\u7a2e\u6709\u6548\u7684 SQL \u65b9\u6cd5\u4f86\u522a\u9664\u91cd\u8907\u8a18\u9304\uff0c\u63d0\u5347\u6578\u64da\u5eab\u7684\u6574\u6f54\u6027\u548c\u6027\u80fd\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-143897","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143897","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=143897"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143897\/revisions"}],"predecessor-version":[{"id":143898,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143897\/revisions\/143898"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=143897"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=143897"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=143897"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}