{"id":165601,"date":"2024-11-05T12:50:23","date_gmt":"2024-11-05T04:50:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/165601\/"},"modified":"2024-11-05T12:50:24","modified_gmt":"2024-11-05T04:50:24","slug":"%e5%bf%ab%e6%8d%b7%e6%9f%a5%e8%a9%a2%ef%bc%9a%e7%8d%b2%e5%8f%96%e4%b8%8d%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e5%85%a9%e5%80%8b%e8%a1%a8-%e6%9f%a5%e8%a9%a2%e5%85%a9%e5%80%8b%e8%a1%a8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/165601\/","title":{"rendered":"\u5feb\u6377\u67e5\u8a62\uff1a\u7372\u53d6\u4e0d\u91cd\u8907\u6578\u64da\u5eab\u7684\u5169\u500b\u8868 (\u67e5\u8a62\u5169\u500b\u8868\u4e0d\u91cd\u8907\u7684\u6578\u64da\u5eab)"},"content":{"rendered":"<h1 id=\"%e5%bf%ab%e6%8d%b7%e6%9f%a5%e8%a9%a2%ef%bc%9a%e7%8d%b2%e5%8f%96%e4%b8%8d%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e5%85%a9%e5%80%8b%e8%a1%a8-%e6%9f%a5%e8%a9%a2%e5%85%a9%e5%80%8b%e8%a1%a8-HoCqhgDdmJ\">\u5feb\u6377\u67e5\u8a62\uff1a\u7372\u53d6\u4e0d\u91cd\u8907\u6578\u64da\u5eab\u7684\u5169\u500b\u8868 (\u67e5\u8a62\u5169\u500b\u8868\u4e0d\u91cd\u8907\u7684\u6578\u64da\u5eab)<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u67e5\u8a62\u4e0d\u91cd\u8907\u7684\u6578\u64da\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002\u7576\u6211\u5011\u9700\u8981\u5f9e\u5169\u500b\u8868\u4e2d\u7372\u53d6\u4e0d\u91cd\u8907\u7684\u6578\u64da\u6642\uff0cSQL \u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u5be6\u73fe\u9019\u4e00\u76ee\u6a19\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8a62\u4f86\u7372\u53d6\u5169\u500b\u8868\u4e2d\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"%e7%90%86%e8%a7%a3%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a1%a8%e7%9a%84%e7%b5%90%e6%a7%8b-HoCqhgDdmJ\">\u7406\u89e3\u6578\u64da\u5eab\u8868\u7684\u7d50\u69cb<\/h2>\n<p>\u5728\u958b\u59cb\u67e5\u8a62\u4e4b\u524d\uff0c\u6211\u5011\u9700\u8981\u4e86\u89e3\u5169\u500b\u8868\u7684\u7d50\u69cb\u3002\u5047\u8a2d\u6211\u5011\u6709\u5169\u500b\u8868\uff1a<code>table_a<\/code> \u548c <code>table_b<\/code>\u3002\u9019\u5169\u500b\u8868\u7684\u7d50\u69cb\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li><code>table_a<\/code>\uff1a\u5305\u542b\u5b57\u6bb5 <code>id<\/code> \u548c <code>name<\/code><\/li>\n<li><code>table_b<\/code>\uff1a\u5305\u542b\u5b57\u6bb5 <code>id<\/code> \u548c <code>name<\/code><\/li>\n<\/ul>\n<p>\u6211\u5011\u7684\u76ee\u6a19\u662f\u5f9e\u9019\u5169\u500b\u8868\u4e2d\u7372\u53d6\u6240\u6709\u4e0d\u91cd\u8907\u7684 <code>name<\/code> \u503c\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-union-%e4%be%86%e6%9f%a5%e8%a9%a2%e4%b8%8d%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a-HoCqhgDdmJ\">\u4f7f\u7528 UNION \u4f86\u67e5\u8a62\u4e0d\u91cd\u8907\u7684\u6578\u64da<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c<code>UNION<\/code> \u64cd\u4f5c\u7b26\u53ef\u4ee5\u7528\u4f86\u5408\u4f75\u5169\u500b\u6216\u591a\u500b SELECT \u8a9e\u53e5\u7684\u7d50\u679c\u96c6\uff0c\u4e26\u81ea\u52d5\u53bb\u9664\u91cd\u8907\u7684\u884c\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528 <code>UNION<\/code> \u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nSELECT name FROM table_a\nUNION\nSELECT name FROM table_b;\n<\/code><\/pre>\n<p>\u9019\u6bb5\u4ee3\u78bc\u5c07\u5f9e <code>table_a<\/code> \u548c <code>table_b<\/code> \u4e2d\u9078\u64c7\u6240\u6709\u7684 <code>name<\/code>\uff0c\u4e26\u8fd4\u56de\u4e0d\u91cd\u8907\u7684\u7d50\u679c\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-left-join-%e5%92%8c-is-null-%e4%be%86%e6%9f%a5%e8%a9%a2%e4%b8%8d%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a-HoCqhgDdmJ\">\u4f7f\u7528 LEFT JOIN \u548c IS NULL \u4f86\u67e5\u8a62\u4e0d\u91cd\u8907\u7684\u6578\u64da<\/h2>\n<p>\u9664\u4e86\u4f7f\u7528 <code>UNION<\/code>\uff0c\u6211\u5011\u9084\u53ef\u4ee5\u4f7f\u7528 <code>LEFT JOIN<\/code> \u4f86\u67e5\u8a62\u4e0d\u91cd\u8907\u7684\u6578\u64da\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u8b93\u6211\u5011\u66f4\u9748\u6d3b\u5730\u63a7\u5236\u67e5\u8a62\u7684\u689d\u4ef6\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528 <code>LEFT JOIN<\/code> \u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nSELECT a.name\nFROM table_a a\nLEFT JOIN table_b b ON a.name = b.name\nWHERE b.name IS NULL;\n<\/code><\/pre>\n<p>\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u5728 <code>table_a<\/code> \u4e2d\u5b58\u5728\u4f46\u5728 <code>table_b<\/code> \u4e2d\u4e0d\u5b58\u5728\u7684\u6240\u6709 <code>name<\/code>\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e8%a9%a2%e5%85%a9%e5%80%8b%e8%a1%a8%e4%b8%ad%e4%b8%8d%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a-HoCqhgDdmJ\">\u67e5\u8a62\u5169\u500b\u8868\u4e2d\u4e0d\u91cd\u8907\u7684\u6578\u64da<\/h2>\n<p>\u5982\u679c\u6211\u5011\u60f3\u8981\u7372\u53d6\u5169\u500b\u8868\u4e2d\u6240\u6709\u4e0d\u91cd\u8907\u7684 <code>name<\/code>\uff0c\u53ef\u4ee5\u7d50\u5408\u4f7f\u7528 <code>UNION<\/code> \u548c <code>LEFT JOIN<\/code>\u3002\u4ee5\u4e0b\u662f\u5b8c\u6574\u7684\u67e5\u8a62\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nSELECT name FROM table_a\nUNION\nSELECT name FROM table_b\nWHERE name NOT IN (SELECT name FROM table_a);\n<\/code><\/pre>\n<p>\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u5728 <code>table_a<\/code> \u548c <code>table_b<\/code> \u4e2d\u7684\u6240\u6709\u4e0d\u91cd\u8907\u7684 <code>name<\/code>\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-HoCqhgDdmJ\">\u7e3d\u7d50<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u67e5\u8a62\u4e2d\uff0c\u7372\u53d6\u4e0d\u91cd\u8907\u7684\u6578\u64da\u662f\u4e00\u500b\u91cd\u8981\u7684\u64cd\u4f5c\u3002\u901a\u904e\u4f7f\u7528 <code>UNION<\/code> \u548c <code>LEFT JOIN<\/code>\uff0c\u6211\u5011\u53ef\u4ee5\u6709\u6548\u5730\u5f9e\u5169\u500b\u8868\u4e2d\u63d0\u53d6\u4e0d\u91cd\u8907\u7684\u6578\u64da\u3002\u9019\u4e9b\u6280\u8853\u4e0d\u50c5\u63d0\u9ad8\u4e86\u67e5\u8a62\u7684\u6548\u7387\uff0c\u9084\u80fd\u5e6b\u52a9\u6211\u5011\u66f4\u597d\u5730\u7ba1\u7406\u6578\u64da\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u4f86\u652f\u6301\u60a8\u7684\u61c9\u7528\u7a0b\u5e8f\u548c\u6578\u64da\u7ba1\u7406\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u670d\u52a1\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u63d0\u4f9b\u7a69\u5b9a\u548c\u53ef\u9760\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5feb\u901f\u67e5\u8a62\u5169\u500b\u8868\u4e2d\u7684\u4e0d\u91cd\u8907\u6578\u64da\uff0c\u8f15\u9b06\u7372\u53d6\u6578\u64da\u5eab\u4e2d\u7368\u7279\u7684\u8cc7\u8a0a\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u6548\u7387\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-165601","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/165601","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=165601"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/165601\/revisions"}],"predecessor-version":[{"id":165602,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/165601\/revisions\/165602"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=165601"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=165601"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=165601"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}