{"id":173391,"date":"2024-11-07T17:38:20","date_gmt":"2024-11-07T09:38:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/173391\/"},"modified":"2024-11-07T17:38:21","modified_gmt":"2024-11-07T09:38:21","slug":"%e5%a6%82%e4%bd%95%e9%ab%98%e6%95%88%e5%88%aa%e9%99%a4%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%9f-%e5%88%aa%e9%99%a4%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/173391\/","title":{"rendered":"\u5982\u4f55\u9ad8\u6548\u522a\u9664\u6578\u64da\u5eab\u4e2d\u91cd\u8907\u7684\u6578\u64da\uff1f (\u522a\u9664\u6578\u64da\u5eab\u4e2d\u91cd\u8907\u7684\u6578\u64da)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e9%ab%98%e6%95%88%e5%88%aa%e9%99%a4%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%9f-PERzvrOVfd\">\u5982\u4f55\u9ad8\u6548\u522a\u9664\u6578\u64da\u5eab\u4e2d\u91cd\u8907\u7684\u6578\u64da\uff1f<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u91cd\u8907\u6578\u64da\u7684\u5b58\u5728\u4e0d\u50c5\u6703\u4f54\u7528\u5b58\u5132\u7a7a\u9593\uff0c\u9084\u53ef\u80fd\u5c0e\u81f4\u67e5\u8a62\u6548\u7387\u4e0b\u964d\u548c\u6578\u64da\u4e0d\u4e00\u81f4\u6027\u3002\u56e0\u6b64\uff0c\u5b78\u6703\u5982\u4f55\u9ad8\u6548\u5730\u522a\u9664\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\u662f\u6bcf\u4f4d\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u5fc5\u9808\u638c\u63e1\u7684\u6280\u80fd\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u6709\u6548\u7684\u65b9\u6cd5\u4f86\u8b58\u5225\u548c\u522a\u9664\u91cd\u8907\u6578\u64da\u3002<\/p>\n<h2 id=\"%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e8%ad%98%e5%88%a5-PERzvrOVfd\">\u91cd\u8907\u6578\u64da\u7684\u8b58\u5225<\/h2>\n<p>\u5728\u522a\u9664\u91cd\u8907\u6578\u64da\u4e4b\u524d\uff0c\u9996\u5148\u9700\u8981\u8b58\u5225\u54ea\u4e9b\u6578\u64da\u662f\u91cd\u8907\u7684\u3002\u9019\u901a\u5e38\u53ef\u4ee5\u901a\u904e SQL \u67e5\u8a62\u4f86\u5be6\u73fe\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u57fa\u672c\u7684 SQL \u67e5\u8a62\u793a\u4f8b\uff0c\u7528\u65bc\u67e5\u627e\u91cd\u8907\u7684\u8a18\u9304\uff1a<\/p>\n<pre><code>SELECT column_name, COUNT(*)\nFROM table_name\nGROUP BY column_name\nHAVING COUNT(*) &gt; 1;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u60a8\u9700\u8981\u5c07 <code>column_name<\/code> \u66ff\u63db\u70ba\u60a8\u60f3\u8981\u6aa2\u67e5\u7684\u5217\u540d\uff0c<code>table_name<\/code> \u66ff\u63db\u70ba\u60a8\u7684\u6578\u64da\u8868\u540d\u7a31\u3002\u9019\u6a23\u53ef\u4ee5\u627e\u51fa\u6240\u6709\u91cd\u8907\u7684\u8a18\u9304\u53ca\u5176\u51fa\u73fe\u6b21\u6578\u3002<\/p>\n<h2 id=\"%e5%88%aa%e9%99%a4%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e6%96%b9%e6%b3%95-PERzvrOVfd\">\u522a\u9664\u91cd\u8907\u6578\u64da\u7684\u65b9\u6cd5<\/h2>\n<p>\u4e00\u65e6\u8b58\u5225\u51fa\u91cd\u8907\u6578\u64da\uff0c\u63a5\u4e0b\u4f86\u5c31\u662f\u522a\u9664\u5b83\u5011\u3002\u4ee5\u4e0b\u662f\u5e7e\u7a2e\u5e38\u898b\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8-cte%ef%bc%88%e5%85%ac%e7%94%a8%e8%a1%a8%e8%a1%a8%e9%81%94%e5%bc%8f%ef%bc%89-PERzvrOVfd\">1. \u4f7f\u7528 CTE\uff08\u516c\u7528\u8868\u8868\u9054\u5f0f\uff09<\/h3>\n<p>\u4f7f\u7528 CTE \u53ef\u4ee5\u65b9\u4fbf\u5730\u522a\u9664\u91cd\u8907\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff1a<\/p>\n<pre><code>WITH CTE AS (\n    SELECT *,\n           ROW_NUMBER() OVER (PARTITION BY column_name ORDER BY (SELECT NULL)) AS row_num\n    FROM table_name\n)\nDELETE FROM CTE WHERE row_num &gt; 1;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c<code>ROW_NUMBER()<\/code> \u51fd\u6578\u70ba\u6bcf\u4e00\u7d44\u91cd\u8907\u7684\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<h3 id=\"2-%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%a9%a2-PERzvrOVfd\">2. \u4f7f\u7528\u5b50\u67e5\u8a62<\/h3>\n<p>\u53e6\u4e00\u7a2e\u65b9\u6cd5\u662f\u4f7f\u7528\u5b50\u67e5\u8a62\u4f86\u522a\u9664\u91cd\u8907\u6578\u64da\uff1a<\/p>\n<pre><code>DELETE FROM table_name\nWHERE id NOT IN (\n    SELECT MIN(id)\n    FROM table_name\n    GROUP BY column_name\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c<code>id<\/code> \u662f\u6bcf\u689d\u8a18\u9304\u7684\u552f\u4e00\u6a19\u8b58\u7b26\uff0c\u9019\u6a23\u53ef\u4ee5\u4fdd\u7559\u6bcf\u7d44\u91cd\u8907\u8a18\u9304\u4e2d\u7684\u4e00\u689d\u3002<\/p>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8-distinct-%e4%be%86%e5%89%b5%e5%bb%ba%e6%96%b0%e8%a1%a8-PERzvrOVfd\">3. \u4f7f\u7528 DISTINCT \u4f86\u5275\u5efa\u65b0\u8868<\/h3>\n<p>\u5982\u679c\u60a8\u5e0c\u671b\u4fdd\u7559\u539f\u59cb\u6578\u64da\u4e26\u5275\u5efa\u4e00\u500b\u4e0d\u5305\u542b\u91cd\u8907\u6578\u64da\u7684\u65b0\u8868\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>DISTINCT<\/code> \u95dc\u9375\u5b57\uff1a<\/p>\n<pre><code>CREATE TABLE new_table AS\nSELECT DISTINCT *\nFROM table_name;<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u5c07\u4e0d\u91cd\u8907\u7684\u6578\u64da\u8907\u88fd\u5230\u65b0\u8868\u4e2d\uff0c\u7136\u5f8c\u60a8\u53ef\u4ee5\u9078\u64c7\u522a\u9664\u539f\u59cb\u8868\u6216\u4fdd\u7559\u5b83\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-PERzvrOVfd\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u522a\u9664\u91cd\u8907\u6578\u64da\u4e4b\u524d\uff0c\u5efa\u8b70\u60a8\u5148\u5099\u4efd\u6578\u64da\u5eab\uff0c\u4ee5\u9632\u6b62\u610f\u5916\u522a\u9664\u91cd\u8981\u6578\u64da\u3002\u6b64\u5916\uff0c\u78ba\u4fdd\u5728\u522a\u9664\u64cd\u4f5c\u5f8c\u9032\u884c\u6578\u64da\u5b8c\u6574\u6027\u6aa2\u67e5\uff0c\u4ee5\u78ba\u4fdd\u6578\u64da\u7684\u4e00\u81f4\u6027\u548c\u6e96\u78ba\u6027\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-PERzvrOVfd\">\u7e3d\u7d50<\/h2>\n<p>\u522a\u9664\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\u662f\u4e00\u9805\u91cd\u8981\u7684\u6578\u64da\u7ba1\u7406\u4efb\u52d9\uff0c\u80fd\u5920\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u53ef\u9760\u6027\u3002\u901a\u904e\u4f7f\u7528 CTE\u3001\u5b50\u67e5\u8a62\u6216 <code>DISTINCT<\/code> \u7b49\u65b9\u6cd5\uff0c\u60a8\u53ef\u4ee5\u6709\u6548\u5730\u8b58\u5225\u548c\u522a\u9664\u91cd\u8907\u6578\u64da\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u7684\u4f01\u696d\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u81f3\u95dc\u91cd\u8981\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u7684\u7a69\u5b9a\u6027\u548c\u5b89\u5168\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u9ad8\u6548\u522a\u9664\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u8cea\u91cf\uff0c\u512a\u5316\u67e5\u8a62\u6027\u80fd\uff0c\u78ba\u4fdd\u6578\u64da\u5eab\u7684\u6574\u6f54\u8207\u6e96\u78ba\u6027\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-173391","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/173391","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=173391"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/173391\/revisions"}],"predecessor-version":[{"id":173392,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/173391\/revisions\/173392"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=173391"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=173391"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=173391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}