{"id":200674,"date":"2025-05-06T13:17:40","date_gmt":"2025-05-06T05:17:40","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200674\/"},"modified":"2025-05-06T13:17:40","modified_gmt":"2025-05-06T05:17:40","slug":"%e5%a6%82%e4%bd%95%e6%9f%a5%e8%af%a2%e5%85%b3%e8%81%94%e8%a1%a8%e4%b8%ad%e6%bb%a1%e8%b6%b3%e7%89%b9%e5%ae%9a%e6%9d%a1%e4%bb%b6%e7%9a%84%e4%b8%a4%e7%bb%84%e6%95%b0%e6%8d%ae%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200674\/","title":{"rendered":"\u5982\u4f55\u67e5\u8be2\u5173\u8054\u8868\u4e2d\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u4e24\u7ec4\u6570\u636e\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u67e5\u8be2\u5173\u8054\u8868\u4e2d\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u4e24\u7ec4\u6570\u636e\uff1f<\/h1>\n<p>\u4f60\u5728\u5b66\u4e60\u76f8\u5173\u7684\u77e5\u8bc6\u5417\uff1f\u672c\u6587\uff0c\u4e3b\u8981\u4ecb\u7ecd\u7684\u5185\u5bb9\u5c31\u6d89\u53ca\u5230\uff0c\u5982\u679c\u4f60\u60f3\u63d0\u5347\u81ea\u5df1\u7684\u5f00\u53d1\u80fd\u529b\uff0c\u5c31\u4e0d\u8981\u9519\u8fc7\u8fd9\u7bc7\u6587\u7ae0\uff0c\u5927\u5bb6\u8981\u77e5\u9053\u7f16\u7a0b\u7406\u8bba\u57fa\u7840\u548c\u5b9e\u6218\u64cd\u4f5c\u90fd\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\u54e6\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241111\/173130088867318e1853a4e.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u5982\u4f55\u89e3\u51b3 mysql \u5173\u8054\u8868\u67e5\u8be2\u95ee\u9898\uff1f<\/strong><\/p>\n<p>\u8bbe\u6709\u8868 a \u548c b\uff0c\u8868 a \u7684 outer_id \u5217\u8fde\u63a5\u8868 b \u7684 id \u5217\u3002\u73b0\u5728\u9700\u8981\u67e5\u8be2\u8868 a \u7684\u4e24\u7ec4\u6570\u636e\uff1a<\/p>\n<ul>\n<li>\u4e00\u7ec4\u662f\u8868 a \u7684 outer_id \u5173\u8054\u8868 b \u7684 id\uff0c\u5982\u679c\u5173\u8054\uff0ctype \u5217\u4e0d\u80fd\u4e3a 99\uff1b\u5982\u679c\u672a\u5173\u8054\uff0c\u4e5f\u9700\u8981\u8fd9\u7ec4\u6570\u636e\u3002<\/li>\n<li>\u53e6\u4e00\u7ec4\u662f\u8868 b \u5fc5\u987b\u5b58\u5728\uff0c\u5e76\u4e14 type \u5217\u7b49\u4e8e 99\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0b\u662f\u67e5\u8be2\u8fd9\u4e24\u7ec4\u6570\u636e\u7684 sql \u8bed\u53e5\uff1a<\/p>\n<p><strong>\u67e5\u8be2\u7b2c\u4e00\u7ec4\u6570\u636e<\/strong><\/p>\n<pre>select a.*\nfrom a a\nleft join b b on b.id = a.outer_id\nwhere b.id is null\n   or (b.id is not null and b.type != 99)<\/pre>\n<p><strong>\u67e5\u8be2\u7b2c\u4e8c\u7ec4\u6570\u636e<\/strong><\/p>\n<pre>SELECT a.*\nFROM A a\nINNER JOIN B b ON b.id = a.outer_id AND b.type = 99<\/pre>\n<p>\u4eca\u5929\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u5e0c\u671b\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff1b\u5173\u4e8e\u6570\u636e\u5e93\u7684\u6280\u672f\u77e5\u8bc6\u6211\u4eec\u4f1a\u4e00\u70b9\u70b9\u6df1\u5165\u4ecb\u7ecd\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u4e00\u8d77\u5b66\u4e60\u7f16\u7a0b~<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u67e5\u8be2\u5173\u8054\u8868\u4e2d\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u4e24&#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-200674","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200674","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=200674"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200674\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200674"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200674"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200674"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}