{"id":200397,"date":"2025-05-06T12:13:19","date_gmt":"2025-05-06T04:13:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200397\/"},"modified":"2025-05-06T12:13:19","modified_gmt":"2025-05-06T04:13:19","slug":"%e5%a6%82%e4%bd%95%e6%9f%a5%e8%af%a2%e5%b8%a6%e6%9c%89%e7%a9%ba%e5%85%b3%e8%81%94%e6%95%b0%e6%8d%ae%e7%9a%84-mysql-%e6%95%b0%e6%8d%ae%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200397\/","title":{"rendered":"\u5982\u4f55\u67e5\u8be2\u5e26\u6709\u7a7a\u5173\u8054\u6570\u636e\u7684 MySQL \u6570\u636e\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u67e5\u8be2\u5e26\u6709\u7a7a\u5173\u8054\u6570\u636e\u7684 MySQL \u6570\u636e\uff1f<\/h1>\n<p>\u6570\u636e\u5e93\u5c0f\u767d\u4e00\u679a\uff0c\u6b63\u5728\u4e0d\u65ad\u5b66\u4e60\u79ef\u7d2f\u77e5\u8bc6\uff0c\u73b0\u5c06\u5b66\u4e60\u5230\u7684\u77e5\u8bc6\u8bb0\u5f55\u4e00\u4e0b\uff0c\u4e5f\u662f\u5c06\u6211\u7684\u6240\u5f97\u5206\u4eab\u7ed9\u5927\u5bb6\uff01\u800c\u4eca\u5929\u8fd9\u7bc7\u6587\u7ae0\u300a\u5982\u4f55\u67e5\u8be2\u5e26\u6709\u7a7a\u5173\u8054\u6570\u636e\u7684 MySQL \u6570\u636e\uff1f\u300b\u5e26\u5927\u5bb6\u6765\u4e86\u89e3\u4e00\u4e0b##content_title##\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u4ece\u800c\u5f25\u8865\u81ea\u5df1\u7684\u4e0d\u8db3\uff0c\u52a9\u529b\u5b9e\u6218\u5f00\u53d1\uff01<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241104\/17306878096728334177345.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>mysql 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c_id \u4e3a 0 \u65f6\uff0c\u65e0\u6cd5\u67e5\u8be2\u51fa\u5b8c\u6574\u7684\u8bb0\u5f55\u3002<\/p>\n<p><strong>\u89e3\u51b3\u65b9\u6cd5\uff1a\u5916\u8fde\u63a5<\/strong><\/p>\n<p>\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u53ef\u4ee5\u4f7f\u7528\u5916\u8fde\u63a5\u3002\u5916\u8fde\u63a5\u5141\u8bb8\u8868\u4e4b\u95f4\u8fdb\u884c\u8fde\u63a5\uff0c\u5373\u4f7f\u5176\u4e2d\u4e00\u5f20\u8868\u4e2d\u5b58\u5728\u7a7a\u503c\u3002<\/p>\n<p>\u4fee\u6539\u540e\u7684\u67e5\u8be2\u5982\u4e0b\uff1a<\/p>\n<pre>select d.id, a.name as a_name, b.name as b_name, c.name as c_name\nfrom D as d\nleft join A as a on a.id=d.a_id\nleft join B as b on b.id=d.b_id\nleft join C as c on c.id=d.c_id<\/pre>\n<p>\u901a\u8fc7\u4f7f\u7528 left join\uff0c\u5f53 d \u8868\u4e2d\u5b58\u5728\u7a7a\u503c\u65f6\uff0c\u5173\u8054\u8868\u4e2d\u7684\u76f8\u5e94\u6570\u636e\u5c06\u663e\u793a\u4e3a\u7a7a\u3002\u8fd9\u4f7f\u6211\u4eec\u80fd\u591f\u67e5\u8be2\u51fa d \u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u65e0\u8bba\u5176\u5173\u8054\u6570\u636e\u662f\u5426\u5b58\u5728\u3002<\/p>\n<p>\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300a\u5982\u4f55\u67e5\u8be2\u5e26\u6709\u7a7a\u5173\u8054\u6570\u636e\u7684 MySQL \u6570\u636e\uff1f\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6570\u636e\u5e93\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u67e5\u8be2\u5e26\u6709\u7a7a\u5173\u8054\u6570\u636e\u7684 MyS&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200397","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200397","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200397"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200397\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200397"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200397"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200397"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}