{"id":179340,"date":"2024-11-09T01:00:22","date_gmt":"2024-11-08T17:00:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179340\/"},"modified":"2024-11-09T01:00:23","modified_gmt":"2024-11-08T17:00:23","slug":"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e6%89%be%e5%87%ba%e5%85%a9%e5%bc%b5%e8%a1%a8%e7%9a%84%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%ef%bc%9f-sql-%e6%89%be%e5%87%ba%e5%85%a9%e5%bc%b5%e8%a1%a8%e7%9a%84%e9%87%8d","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179340\/","title":{"rendered":"\u5982\u4f55\u7528 SQL \u627e\u51fa\u5169\u5f35\u8868\u7684\u91cd\u8907\u6578\u64da\uff1f (sql \u627e\u51fa\u5169\u5f35\u8868\u7684\u91cd\u8907\u6578\u64da\u5eab)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e6%89%be%e5%87%ba%e5%85%a9%e5%bc%b5%e8%a1%a8%e7%9a%84%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%ef%bc%9f-sNCUaKXmNG\">\u5982\u4f55\u7528 SQL \u627e\u51fa\u5169\u5f35\u8868\u7684\u91cd\u8907\u6578\u64da\uff1f<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u91cd\u8907\u6578\u64da\u7684\u5b58\u5728\u53ef\u80fd\u6703\u5c0e\u81f4\u6578\u64da\u4e0d\u4e00\u81f4\u6027\uff0c\u5f71\u97ff\u67e5\u8a62\u7d50\u679c\u7684\u6e96\u78ba\u6027\u3002\u56e0\u6b64\uff0c\u627e\u51fa\u4e26\u8655\u7406\u91cd\u8907\u6578\u64da\u662f\u6578\u64da\u6e05\u7406\u7684\u91cd\u8981\u6b65\u9a5f\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8a62\u4f86\u627e\u51fa\u5169\u5f35\u8868\u4e2d\u7684\u91cd\u8907\u6578\u64da\uff0c\u4e26\u63d0\u4f9b\u76f8\u95dc\u7684\u7bc4\u4f8b\u548c\u4ee3\u78bc\u3002<\/p>\n<h2 id=\"%e7%90%86%e8%a7%a3%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-sNCUaKXmNG\">\u7406\u89e3\u91cd\u8907\u6578\u64da<\/h2>\n<p>\u91cd\u8907\u6578\u64da\u662f\u6307\u5728\u6578\u64da\u5eab\u4e2d\u51fa\u73fe\u591a\u6b21\u7684\u76f8\u540c\u6578\u64da\u884c\u3002\u9019\u4e9b\u91cd\u8907\u884c\u53ef\u80fd\u662f\u7531\u65bc\u6578\u64da\u8f38\u5165\u932f\u8aa4\u3001\u6578\u64da\u5408\u4f75\u6216\u5176\u4ed6\u539f\u56e0\u9020\u6210\u7684\u3002\u5728\u9032\u884c\u6578\u64da\u5206\u6790\u6216\u5831\u544a\u6642\uff0c\u91cd\u8907\u6578\u64da\u53ef\u80fd\u6703\u5c0e\u81f4\u932f\u8aa4\u7684\u7d50\u8ad6\uff0c\u56e0\u6b64\u9700\u8981\u53ca\u6642\u8b58\u5225\u548c\u8655\u7406\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-sql-%e6%9f%a5%e8%a9%a2%e6%89%be%e5%87%ba%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-sNCUaKXmNG\">\u4f7f\u7528 SQL \u67e5\u8a62\u627e\u51fa\u91cd\u8907\u6578\u64da<\/h2>\n<p>\u8981\u627e\u51fa\u5169\u5f35\u8868\u4e2d\u7684\u91cd\u8907\u6578\u64da\uff0c\u901a\u5e38\u53ef\u4ee5\u4f7f\u7528 SQL \u7684 JOIN \u8a9e\u53e5\u4f86\u9032\u884c\u6bd4\u8f03\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"%e6%96%b9%e6%b3%95%e4%b8%80%ef%bc%9a%e4%bd%bf%e7%94%a8-inner-join-sNCUaKXmNG\">\u65b9\u6cd5\u4e00\uff1a\u4f7f\u7528 INNER JOIN<\/h3>\n<p>INNER JOIN \u53ef\u4ee5\u7528\u4f86\u627e\u51fa\u5169\u5f35\u8868\u4e2d\u76f8\u540c\u7684\u6578\u64da\u3002\u5047\u8a2d\u6211\u5011\u6709\u5169\u5f35\u8868\uff0c\u5206\u5225\u70ba <code>table1<\/code> \u548c <code>table2<\/code>\uff0c\u4e26\u4e14\u6211\u5011\u8981\u627e\u51fa\u9019\u5169\u5f35\u8868\u4e2d\u5728 <code>id<\/code> \u6b04\u4f4d\u4e0a\u91cd\u8907\u7684\u6578\u64da\u3002<\/p>\n<pre><code>SELECT a.*\nFROM table1 a\nINNER JOIN table2 b ON a.id = b.id;<\/code><\/pre>\n<p>\u9019\u6bb5 SQL \u67e5\u8a62\u6703\u8fd4\u56de <code>table1<\/code> \u4e2d\u6240\u6709\u8207 <code>table2<\/code> \u4e2d\u7684 <code>id<\/code> \u6b04\u4f4d\u76f8\u540c\u7684\u884c\u3002<\/p>\n<h3 id=\"%e6%96%b9%e6%b3%95%e4%ba%8c%ef%bc%9a%e4%bd%bf%e7%94%a8-exists-sNCUaKXmNG\">\u65b9\u6cd5\u4e8c\uff1a\u4f7f\u7528 EXISTS<\/h3>\n<p>\u53e6\u4e00\u7a2e\u65b9\u6cd5\u662f\u4f7f\u7528 EXISTS \u5b50\u53e5\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u7528\u4f86\u6aa2\u67e5\u67d0\u500b\u689d\u4ef6\u662f\u5426\u5b58\u5728\u65bc\u53e6\u4e00\u5f35\u8868\u4e2d\u3002<\/p>\n<pre><code>SELECT *\nFROM table1 a\nWHERE EXISTS (\n    SELECT 1\n    FROM table2 b\n    WHERE a.id = b.id\n);<\/code><\/pre>\n<p>\u9019\u6bb5\u67e5\u8a62\u6703\u8fd4\u56de\u6240\u6709\u5728 <code>table1<\/code> \u4e2d\u7684\u884c\uff0c\u524d\u63d0\u662f\u9019\u4e9b\u884c\u7684 <code>id<\/code> \u5728 <code>table2<\/code> \u4e2d\u4e5f\u5b58\u5728\u3002<\/p>\n<h3 id=\"%e6%96%b9%e6%b3%95%e4%b8%89%ef%bc%9a%e4%bd%bf%e7%94%a8-union-%e5%92%8c-group-by-sNCUaKXmNG\">\u65b9\u6cd5\u4e09\uff1a\u4f7f\u7528 UNION \u548c GROUP BY<\/h3>\n<p>\u5982\u679c\u6211\u5011\u60f3\u8981\u627e\u51fa\u6240\u6709\u91cd\u8907\u7684 <code>id<\/code>\uff0c\u53ef\u4ee5\u4f7f\u7528 UNION \u5c07\u5169\u5f35\u8868\u7684 <code>id<\/code> \u5408\u4f75\uff0c\u7136\u5f8c\u4f7f\u7528 GROUP BY \u548c HAVING \u4f86\u904e\u6ffe\u51fa\u91cd\u8907\u7684\u9805\u76ee\u3002<\/p>\n<pre><code>SELECT id\nFROM (\n    SELECT id FROM table1\n    UNION ALL\n    SELECT id FROM table2\n) AS combined\nGROUP BY id\nHAVING COUNT(*) &gt; 1;<\/code><\/pre>\n<p>\u9019\u6bb5\u67e5\u8a62\u6703\u8fd4\u56de\u6240\u6709\u5728\u5169\u5f35\u8868\u4e2d\u51fa\u73fe\u8d85\u904e\u4e00\u6b21\u7684 <code>id<\/code>\u3002<\/p>\n<h2 id=\"%e8%99%95%e7%90%86%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a-sNCUaKXmNG\">\u8655\u7406\u91cd\u8907\u6578\u64da<\/h2>\n<p>\u627e\u51fa\u91cd\u8907\u6578\u64da\u5f8c\uff0c\u63a5\u4e0b\u4f86\u7684\u6b65\u9a5f\u662f\u5982\u4f55\u8655\u7406\u9019\u4e9b\u6578\u64da\u3002\u5e38\u898b\u7684\u8655\u7406\u65b9\u6cd5\u5305\u62ec\uff1a<\/p>\n<ul>\n<li>\u522a\u9664\u91cd\u8907\u884c\uff1a\u53ef\u4ee5\u4f7f\u7528 DELETE \u8a9e\u53e5\u522a\u9664\u91cd\u8907\u7684\u6578\u64da\u3002<\/li>\n<li>\u5408\u4f75\u6578\u64da\uff1a\u5982\u679c\u91cd\u8907\u7684\u6578\u64da\u6709\u4e0d\u540c\u7684\u6b04\u4f4d\u503c\uff0c\u53ef\u4ee5\u8003\u616e\u5408\u4f75\u9019\u4e9b\u6578\u64da\u3002<\/li>\n<li>\u6a19\u8a18\u91cd\u8907\uff1a\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u53ef\u80fd\u9700\u8981\u4fdd\u7559\u91cd\u8907\u6578\u64da\uff0c\u4f46\u9700\u8981\u6a19\u8a18\u4ee5\u4fbf\u5f8c\u7e8c\u8655\u7406\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-sNCUaKXmNG\">\u7e3d\u7d50<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u627e\u51fa\u91cd\u8907\u6578\u64da\u662f\u4e00\u500b\u91cd\u8981\u7684\u4efb\u52d9\u3002\u901a\u904e\u4f7f\u7528 SQL \u7684 JOIN\u3001EXISTS \u548c GROUP BY \u7b49\u8a9e\u53e5\uff0c\u6211\u5011\u53ef\u4ee5\u6709\u6548\u5730\u8b58\u5225\u548c\u8655\u7406\u91cd\u8907\u6578\u64da\u3002\u9019\u4e0d\u50c5\u6709\u52a9\u65bc\u63d0\u9ad8\u6578\u64da\u7684\u6e96\u78ba\u6027\uff0c\u9084\u80fd\u589e\u5f37\u6578\u64da\u5206\u6790\u7684\u53ef\u9760\u6027\u3002<\/p>\n<p>\u5982\u679c\u60a8\u9700\u8981\u9032\u4e00\u6b65\u7684\u6578\u64da\u5eab\u7ba1\u7406\u89e3\u6c7a\u65b9\u6848\uff0c\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">VPS<\/a> \u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8a62\u627e\u51fa\u5169\u5f35\u8868\u4e2d\u7684\u91cd\u8907\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u6548\u7387\uff0c\u78ba\u4fdd\u6578\u64da\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-179340","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179340","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=179340"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179340\/revisions"}],"predecessor-version":[{"id":179341,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179340\/revisions\/179341"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179340"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179340"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179340"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}