{"id":163713,"date":"2024-11-05T01:48:22","date_gmt":"2024-11-04T17:48:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/163713\/"},"modified":"2024-11-05T01:48:23","modified_gmt":"2024-11-04T17:48:23","slug":"%e8%a7%a3%e6%b1%basql%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e6%95%b8%e6%93%9a%e9%87%8d%e8%a4%87%e5%95%8f%e9%a1%8c%e7%9a%84%e6%96%b9%e6%b3%95-sql%e6%95%b8%e6%93%9a%e5%ba%ab%e6%95%b8%e6%93%9a%e9%87%8d","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/163713\/","title":{"rendered":"\u89e3\u6c7aSQL\u6578\u64da\u5eab\u4e2d\u6578\u64da\u91cd\u8907\u554f\u984c\u7684\u65b9\u6cd5 (sql\u6578\u64da\u5eab\u6578\u64da\u91cd\u8907\u7684\u6578\u64da)"},"content":{"rendered":"<h1 id=\"%e8%a7%a3%e6%b1%basql%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e6%95%b8%e6%93%9a%e9%87%8d%e8%a4%87%e5%95%8f%e9%a1%8c%e7%9a%84%e6%96%b9%e6%b3%95-wVxnrwlTkG\">\u89e3\u6c7aSQL\u6578\u64da\u5eab\u4e2d\u6578\u64da\u91cd\u8907\u554f\u984c\u7684\u65b9\u6cd5<\/h1>\n<p>\u5728\u73fe\u4ee3\u6578\u64da\u7ba1\u7406\u4e2d\uff0c\u6578\u64da\u91cd\u8907\u662f\u4e00\u500b\u5e38\u898b\u7684\u554f\u984c\uff0c\u5c24\u5176\u662f\u5728SQL\u6578\u64da\u5eab\u4e2d\u3002\u6578\u64da\u91cd\u8907\u4e0d\u50c5\u6703\u6d6a\u8cbb\u5b58\u5132\u7a7a\u9593\uff0c\u9084\u53ef\u80fd\u5c0e\u81f4\u6578\u64da\u4e0d\u4e00\u81f4\u6027\uff0c\u5f71\u97ff\u6578\u64da\u5206\u6790\u7684\u6e96\u78ba\u6027\u3002\u56e0\u6b64\uff0c\u4e86\u89e3\u5982\u4f55\u6709\u6548\u5730\u8b58\u5225\u548c\u89e3\u6c7a\u6578\u64da\u91cd\u8907\u554f\u984c\u662f\u6bcf\u4f4d\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u7684\u91cd\u8981\u4efb\u52d9\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e9%87%8d%e8%a4%87%e7%9a%84%e5%8e%9f%e5%9b%a0-wVxnrwlTkG\">\u6578\u64da\u91cd\u8907\u7684\u539f\u56e0<\/h2>\n<p>\u6578\u64da\u91cd\u8907\u7684\u539f\u56e0\u591a\u7a2e\u591a\u6a23\uff0c\u4e3b\u8981\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong>\u7528\u6236\u8f38\u5165\u932f\u8aa4\uff1a<\/strong>\u7528\u6236\u5728\u8f38\u5165\u6578\u64da\u6642\u53ef\u80fd\u6703\u4e0d\u5c0f\u5fc3\u91cd\u8907\u63d0\u4ea4\u76f8\u540c\u7684\u4fe1\u606f\u3002<\/li>\n<li><strong>\u6578\u64da\u6574\u5408\uff1a<\/strong>\u5728\u5c07\u4f86\u81ea\u4e0d\u540c\u4f86\u6e90\u7684\u6578\u64da\u5408\u4f75\u6642\uff0c\u53ef\u80fd\u6703\u51fa\u73fe\u91cd\u8907\u7684\u8a18\u9304\u3002<\/li>\n<li><strong>\u7f3a\u4e4f\u7d04\u675f\u689d\u4ef6\uff1a<\/strong>\u5982\u679c\u6578\u64da\u8868\u4e2d\u7f3a\u4e4f\u9069\u7576\u7684\u552f\u4e00\u6027\u7d04\u675f\uff0c\u5247\u53ef\u80fd\u6703\u5141\u8a31\u91cd\u8907\u6578\u64da\u7684\u63d2\u5165\u3002<\/li>\n<\/ul>\n<h2 id=\"%e8%ad%98%e5%88%a5%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-wVxnrwlTkG\">\u8b58\u5225\u91cd\u8907\u6578\u64da<\/h2>\n<p>\u5728\u89e3\u6c7a\u6578\u64da\u91cd\u8907\u554f\u984c\u4e4b\u524d\uff0c\u9996\u5148\u9700\u8981\u8b58\u5225\u51fa\u91cd\u8907\u7684\u6578\u64da\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0bSQL\u67e5\u8a62\u4f86\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\u6bb5\u4ee3\u78bc\u4e2d\uff0c\u5c07 <code>column_name<\/code> \u66ff\u63db\u70ba\u9700\u8981\u6aa2\u67e5\u7684\u5217\u540d\uff0c<code>table_name<\/code> \u66ff\u63db\u70ba\u76f8\u61c9\u7684\u8868\u540d\u3002\u9019\u6a23\u53ef\u4ee5\u5217\u51fa\u6240\u6709\u91cd\u8907\u7684\u8a18\u9304\u53ca\u5176\u51fa\u73fe\u7684\u6b21\u6578\u3002<\/p>\n<h2 id=\"%e8%a7%a3%e6%b1%ba%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e6%96%b9%e6%b3%95-wVxnrwlTkG\">\u89e3\u6c7a\u91cd\u8907\u6578\u64da\u7684\u65b9\u6cd5<\/h2>\n<p>\u4e00\u65e6\u8b58\u5225\u51fa\u91cd\u8907\u7684\u6578\u64da\uff0c\u63a5\u4e0b\u4f86\u5c31\u9700\u8981\u63a1\u53d6\u63aa\u65bd\u4f86\u89e3\u6c7a\u9019\u4e9b\u554f\u984c\u3002\u4ee5\u4e0b\u662f\u5e7e\u7a2e\u5e38\u898b\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e5%88%aa%e9%99%a4%e9%87%8d%e8%a4%87%e8%a8%98%e9%8c%84-wVxnrwlTkG\">1. \u522a\u9664\u91cd\u8907\u8a18\u9304<\/h3>\n<p>\u5982\u679c\u78ba\u5b9a\u67d0\u4e9b\u8a18\u9304\u662f\u5b8c\u5168\u91cd\u8907\u7684\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0bSQL\u8a9e\u53e5\u522a\u9664\u91cd\u8907\u7684\u8a18\u9304\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>\u9019\u6bb5\u4ee3\u78bc\u5c07\u4fdd\u7559\u6bcf\u7d44\u91cd\u8907\u8a18\u9304\u4e2d\u7684\u4e00\u500b\uff0c\u4e26\u522a\u9664\u5176\u9918\u7684\u91cd\u8907\u9805\u3002<\/p>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8%e5%94%af%e4%b8%80%e7%b4%84%e6%9d%9f-wVxnrwlTkG\">2. \u4f7f\u7528\u552f\u4e00\u7d04\u675f<\/h3>\n<p>\u70ba\u4e86\u9632\u6b62\u672a\u4f86\u51fa\u73fe\u91cd\u8907\u6578\u64da\uff0c\u53ef\u4ee5\u5728\u6578\u64da\u8868\u4e2d\u6dfb\u52a0\u552f\u4e00\u7d04\u675f\u3002\u9019\u6a23\uff0c\u6578\u64da\u5eab\u5c07\u81ea\u52d5\u963b\u6b62\u91cd\u8907\u6578\u64da\u7684\u63d2\u5165\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0bSQL\u8a9e\u53e5\u4f86\u6dfb\u52a0\u552f\u4e00\u7d04\u675f\uff1a<\/p>\n<pre><code>ALTER TABLE table_name\nADD CONSTRAINT constraint_name UNIQUE (column_name);<\/code><\/pre>\n<h3 id=\"3-%e6%95%b8%e6%93%9a%e6%b8%85%e7%90%86-wVxnrwlTkG\">3. \u6578\u64da\u6e05\u7406<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u91cd\u8907\u7684\u6578\u64da\u53ef\u80fd\u5305\u542b\u6709\u7528\u7684\u4fe1\u606f\u3002\u9019\u6642\uff0c\u53ef\u4ee5\u8003\u616e\u9032\u884c\u6578\u64da\u6e05\u7406\uff0c\u5c07\u91cd\u8907\u7684\u8a18\u9304\u5408\u4f75\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u5c07\u91cd\u8907\u8a18\u9304\u4e2d\u7684\u6578\u64da\u9032\u884c\u532f\u7e3d\u6216\u66f4\u65b0\uff0c\u4ee5\u4fdd\u7559\u6700\u6709\u50f9\u503c\u7684\u4fe1\u606f\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-wVxnrwlTkG\">\u7d50\u8ad6<\/h2>\n<p>\u6578\u64da\u91cd\u8907\u554f\u984c\u5728SQL\u6578\u64da\u5eab\u4e2d\u662f\u4e0d\u53ef\u5ffd\u8996\u7684\uff0c\u53ca\u6642\u8b58\u5225\u548c\u89e3\u6c7a\u9019\u4e9b\u554f\u984c\u5c0d\u65bc\u4fdd\u6301\u6578\u64da\u7684\u6e96\u78ba\u6027\u548c\u4e00\u81f4\u6027\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u4f7f\u7528\u9069\u7576\u7684SQL\u67e5\u8a62\u4f86\u8b58\u5225\u91cd\u8907\u6578\u64da\uff0c\u4e26\u63a1\u53d6\u76f8\u61c9\u7684\u63aa\u65bd\u4f86\u522a\u9664\u6216\u9632\u6b62\u91cd\u8907\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\u8cea\u91cf\u3002<\/p>\n<p>\u5982\u679c\u60a8\u9700\u8981\u9032\u4e00\u6b65\u7684\u652f\u6301\u6216\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u670d\u52d9\u4f86\u63d0\u5347\u60a8\u7684\u6578\u64da\u7ba1\u7406\u80fd\u529b\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7684\u6027\u80fd\u9084\u662f\u5b89\u5168\u6027\uff0c\u9078\u64c7\u5408\u9069\u7684<a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a>\u90fd\u80fd\u70ba\u60a8\u7684\u696d\u52d9\u63d0\u4f9b\u5f37\u6709\u529b\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22\u6709\u6548\u89e3\u6c7aSQL\u6578\u64da\u5eab\u4e2d\u6578\u64da\u91cd\u8907\u554f\u984c\u7684\u65b9\u6cd5\uff0c\u63d0\u5347\u6578\u64da\u8cea\u91cf\u8207\u67e5\u8a62\u6548\u7387\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u6e96\u78ba\u6027\u8207\u4e00\u81f4\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-163713","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/163713","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=163713"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/163713\/revisions"}],"predecessor-version":[{"id":163714,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/163713\/revisions\/163714"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=163713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=163713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=163713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}