{"id":172969,"date":"2024-11-07T15:35:23","date_gmt":"2024-11-07T07:35:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/172969\/"},"modified":"2024-11-07T15:35:23","modified_gmt":"2024-11-07T07:35:23","slug":"%e5%a6%82%e4%bd%95%e6%9f%a5%e6%89%be%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e7%9a%84%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-%e6%9f%a5%e6%89%be%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e9%87%8d%e8%a4%87%e7%9a%84","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/172969\/","title":{"rendered":"\u5982\u4f55\u67e5\u627e\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da (\u67e5\u627e\u6578\u64da\u5eab\u4e2d\u91cd\u8907\u7684\u6578\u64da)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e6%9f%a5%e6%89%be%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e7%9a%84%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-zrCkpBSKpy\">\u5982\u4f55\u67e5\u627e\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da<\/h1>\n<p>\u5728\u6578\u64da\u7ba1\u7406\u4e2d\uff0c\u91cd\u8907\u6578\u64da\u662f\u4e00\u500b\u5e38\u898b\u7684\u554f\u984c\uff0c\u5c24\u5176\u662f\u5728\u5927\u578b\u6578\u64da\u5eab\u4e2d\u3002\u91cd\u8907\u6578\u64da\u4e0d\u50c5\u6703\u4f54\u7528\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\u67e5\u627e\u548c\u8655\u7406\u91cd\u8907\u6578\u64da\u662f\u6578\u64da\u5eab\u7ba1\u7406\u7684\u91cd\u8981\u4efb\u52d9\u4e4b\u4e00\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u6709\u6548\u5730\u67e5\u627e\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e5%ae%9a%e7%be%a9-zrCkpBSKpy\">\u91cd\u8907\u6578\u64da\u7684\u5b9a\u7fa9<\/h2>\n<p>\u91cd\u8907\u6578\u64da\u662f\u6307\u5728\u6578\u64da\u5eab\u4e2d\u51fa\u73fe\u591a\u6b21\u7684\u76f8\u540c\u6578\u64da\u689d\u76ee\u3002\u9019\u4e9b\u91cd\u8907\u7684\u689d\u76ee\u53ef\u80fd\u662f\u7531\u65bc\u591a\u6b21\u8f38\u5165\u3001\u6578\u64da\u5c0e\u5165\u932f\u8aa4\u6216\u7cfb\u7d71\u6574\u5408\u7b49\u539f\u56e0\u9020\u6210\u7684\u3002\u91cd\u8907\u6578\u64da\u53ef\u80fd\u6703\u5c0e\u81f4\u5831\u544a\u932f\u8aa4\u3001\u5ba2\u6236\u95dc\u4fc2\u7ba1\u7406\u554f\u984c\u4ee5\u53ca\u5176\u4ed6\u696d\u52d9\u904b\u71df\u4e0a\u7684\u6311\u6230\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e6%89%be%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e6%96%b9%e6%b3%95-zrCkpBSKpy\">\u67e5\u627e\u91cd\u8907\u6578\u64da\u7684\u65b9\u6cd5<\/h2>\n<p>\u67e5\u627e\u91cd\u8907\u6578\u64da\u7684\u65b9\u6cd5\u53d6\u6c7a\u65bc\u6240\u4f7f\u7528\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff08DBMS\uff09\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u67e5\u627e\u91cd\u8907\u6578\u64da\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8-sql-%e6%9f%a5%e8%a9%a2-zrCkpBSKpy\">1. \u4f7f\u7528 SQL \u67e5\u8a62<\/h3>\n<p>\u5728\u5927\u591a\u6578\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528 SQL \u67e5\u8a62\u4f86\u67e5\u627e\u91cd\u8907\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>customers<\/code> \u7684\u8868\uff0c\u5176\u4e2d\u5305\u542b <code>email<\/code> \u6b04\u4f4d\uff0c\u6211\u5011\u60f3\u8981\u67e5\u627e\u91cd\u8907\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\uff1a<\/p>\n<pre><code>SELECT email, COUNT(*) as count\nFROM customers\nGROUP BY email\nHAVING COUNT(*) &gt; 1;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u91cd\u8907\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u53ca\u5176\u51fa\u73fe\u7684\u6b21\u6578\u3002<\/p>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8-distinct-%e9%97%9c%e9%8d%b5%e5%ad%97-zrCkpBSKpy\">2. \u4f7f\u7528 DISTINCT \u95dc\u9375\u5b57<\/h3>\n<p>\u5982\u679c\u60a8\u53ea\u60f3\u67e5\u770b\u552f\u4e00\u7684\u6578\u64da\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>DISTINCT<\/code> \u95dc\u9375\u5b57\u3002\u4ee5\u4e0b\u662f\u67e5\u627e\u552f\u4e00\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT DISTINCT email\nFROM customers;<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8%e7%aa%97%e5%8f%a3%e5%87%bd%e6%95%b8-zrCkpBSKpy\">3. \u4f7f\u7528\u7a97\u53e3\u51fd\u6578<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u60a8\u53ef\u80fd\u9700\u8981\u66f4\u8907\u96dc\u7684\u67e5\u8a62\u4f86\u67e5\u627e\u91cd\u8907\u6578\u64da\u3002\u7a97\u53e3\u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u60a8\u66f4\u9748\u6d3b\u5730\u8655\u7406\u6578\u64da\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8a62\u4f7f\u7528\u7a97\u53e3\u51fd\u6578\u4f86\u6a19\u8a18\u91cd\u8907\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\uff1a<\/p>\n<pre><code>SELECT email, \n       COUNT(*) OVER (PARTITION BY email) as count\nFROM customers;<\/code><\/pre>\n<p>\u9019\u5c07\u70ba\u6bcf\u500b\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u63d0\u4f9b\u4e00\u500b\u8a08\u6578\uff0c\u60a8\u53ef\u4ee5\u6839\u64da\u9700\u8981\u9032\u4e00\u6b65\u904e\u6ffe\u3002<\/p>\n<h2 id=\"%e8%99%95%e7%90%86%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-zrCkpBSKpy\">\u8655\u7406\u91cd\u8907\u6578\u64da<\/h2>\n<p>\u67e5\u627e\u91cd\u8907\u6578\u64da\u5f8c\uff0c\u60a8\u53ef\u80fd\u9700\u8981\u8003\u616e\u5982\u4f55\u8655\u7406\u9019\u4e9b\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u8655\u7406\u65b9\u6cd5\uff1a<\/p>\n<ul>\n<li><strong>\u522a\u9664\u91cd\u8907\u689d\u76ee\uff1a<\/strong>\u5982\u679c\u91cd\u8907\u7684\u6578\u64da\u4e0d\u518d\u9700\u8981\uff0c\u53ef\u4ee5\u76f4\u63a5\u522a\u9664\u3002<\/li>\n<li><strong>\u5408\u4f75\u6578\u64da\uff1a<\/strong>\u5982\u679c\u91cd\u8907\u7684\u689d\u76ee\u5305\u542b\u4e0d\u540c\u7684\u4fe1\u606f\uff0c\u60a8\u53ef\u80fd\u9700\u8981\u5408\u4f75\u9019\u4e9b\u6578\u64da\u3002<\/li>\n<li><strong>\u6a19\u8a18\u91cd\u8907\uff1a<\/strong>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u60a8\u53ef\u80fd\u5e0c\u671b\u4fdd\u7559\u91cd\u8907\u7684\u6578\u64da\uff0c\u4f46\u9700\u8981\u6a19\u8a18\u5b83\u5011\u4ee5\u4fbf\u5f8c\u7e8c\u8655\u7406\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-zrCkpBSKpy\">\u7d50\u8ad6<\/h2>\n<p>\u67e5\u627e\u548c\u8655\u7406\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\u662f\u4e00\u9805\u91cd\u8981\u7684\u6578\u64da\u7ba1\u7406\u4efb\u52d9\u3002\u901a\u904e\u4f7f\u7528 SQL \u67e5\u8a62\u3001\u7a97\u53e3\u51fd\u6578\u7b49\u6280\u8853\uff0c\u60a8\u53ef\u4ee5\u6709\u6548\u5730\u8b58\u5225\u548c\u8655\u7406\u91cd\u8907\u6578\u64da\uff0c\u5f9e\u800c\u63d0\u9ad8\u6578\u64da\u7684\u6e96\u78ba\u6027\u548c\u4e00\u81f4\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u6216 <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\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\u6709\u6548\u67e5\u627e\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u8cea\u91cf\uff0c\u512a\u5316\u6578\u64da\u7ba1\u7406\u6d41\u7a0b\uff0c\u78ba\u4fdd\u4fe1\u606f\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-172969","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172969","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=172969"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172969\/revisions"}],"predecessor-version":[{"id":172970,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172969\/revisions\/172970"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=172969"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=172969"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=172969"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}