{"id":200198,"date":"2025-05-06T11:50:31","date_gmt":"2025-05-06T03:50:31","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200198\/"},"modified":"2025-05-06T11:50:31","modified_gmt":"2025-05-06T03:50:31","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-mysql-%e6%9f%a5%e8%af%a2%e5%ae%9e%e7%8e%b0%e5%88%86%e7%bb%84%e7%bb%93%e6%9e%9c%e5%b9%b6%e8%a1%8c%e5%b1%95%e7%a4%ba%e4%b8%8a%e5%8d%8a%e5%b9%b4%e5%92%8c%e4%b8%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200198\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528 MySQL \u67e5\u8be2\u5b9e\u73b0\u5206\u7ec4\u7ed3\u679c\u5e76\u884c\u5c55\u793a\u4e0a\u534a\u5e74\u548c\u4e0b\u534a\u5e74\u7edf\u8ba1\u503c\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u4f7f\u7528 MySQL \u67e5\u8be2\u5b9e\u73b0\u5206\u7ec4\u7ed3\u679c\u5e76\u884c\u5c55\u793a\u4e0a\u534a\u5e74\u548c\u4e0b\u534a\u5e74\u7edf\u8ba1\u503c\uff1f<\/h1>\n<p>\u5c0f\u4f19\u4f34\u4eec\u6709\u6ca1\u6709\u89c9\u5f97\u5b66\u4e60\u5f88\u6709\u610f\u601d\uff1f\u6709\u610f\u601d\u5c31\u5bf9\u4e86\uff01\u4eca\u5929\u5c31\u7ed9\u5927\u5bb6\u5e26\u6765\uff0c\u4ee5\u4e0b\u5185\u5bb9\u5c06\u4f1a\u6d89\u53ca\u5230\uff0c\u82e5\u662f\u5728\u5b66\u4e60\u4e2d\u5bf9\u5176\u4e2d\u90e8\u5206\u77e5\u8bc6\u70b9\u6709\u7591\u95ee\uff0c\u6216\u8bb8\u770b\u4e86\u672c\u6587\u5c31\u80fd\u5e2e\u5230\u4f60\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241028\/1730076354671edec26e101.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>mysql \u67e5\u8be2\u7ed3\u679c\u5206\u7ec4\u5e76\u884c\u5c55\u793a<\/strong><\/p>\n<p>\u5bf9\u4e8e\u5206\u7ec4\u67e5\u8be2\u5e76\u884c\u5c55\u793a\u7684\u95ee\u9898\uff0c\u53ef\u4ee5\u4f7f\u7528 group by \u548c left join \u8054\u5408\u5b9e\u73b0\u3002<\/p>\n<p>\u672c\u4f8b\u4e2d\uff0c\u6211\u4eec\u9700\u8981\u6839\u636e name \u548c start_date \u5bf9\u67e5\u8be2\u7ed3\u679c\u8fdb\u884c\u5206\u7ec4\uff0c\u5e76\u5c06\u4e0a\u534a\u5e74\u548c\u4e0b\u534a\u5e74\u7684\u7edf\u8ba1 num \u6c42\u548c\u5c55\u793a\u5728\u540c\u4e00\u884c\u3002<\/p>\n<p>\u4ee5\u4e0b sql \u67e5\u8be2\u53ef\u4ee5\u5b9e\u73b0\u4e0a\u8ff0\u9700\u6c42\uff1a<\/p>\n<pre>SELECT\n    t.name,\n    start_date,\n    SUM( t.num ) AS shang_sum,\n    IFNULL(t2.xia_sum,0)\nFROM\n    `task` t\n    LEFT JOIN ( SELECT NAME, SUM( num ) xia_sum FROM task WHERE MONTH ( start_date ) &amp;lt; 7 GROUP BY `name` ) t2 ON t2.NAME = t.NAME \nWHERE\n    MONTH ( start_date ) &amp;gt;= 7 \nGROUP BY\n    `name`<\/pre>\n<p>\u8be5\u67e5\u8be2\u9996\u5148\u4f7f\u7528 group by \u5bf9\u7ed3\u679c\u6309\u7167 name \u8fdb\u884c\u5206\u7ec4\uff0c\u5e76\u8ba1\u7b97\u4e0a\u534a\u5e74\u7684 num \u6c42\u548c\u3002\u7136\u540e\u4f7f\u7528 left join \u5de6\u8fde\u63a5\u53e6\u4e00\u4e2a\u5b50\u67e5\u8be2\uff0c\u8be5\u5b50\u67e5\u8be2\u4ece\u6ee1\u8db3 start_date \u5728\u4e0a\u534a\u5e74\u7684 task \u8868\u4e2d\u8ba1\u7b97\u4e0b\u534a\u5e74\u7684 num \u6c42\u548c\u3002\u6700\u540e\uff0cifnull \u51fd\u6570\u7528\u4e8e\u5904\u7406\u4e0b\u534a\u5e74\u7684\u6c42\u548c\u7ed3\u679c\u4e3a null \u7684\u60c5\u51b5\uff0c\u5c06\u5176\u66ff\u6362\u4e3a 0\u3002<\/p>\n<p>\u6267\u884c\u8be5\u67e5\u8be2\u540e\uff0c\u5c06\u8f93\u51fa\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th>name<\/th>\n<th>start_date<\/th>\n<th>shang_sum<\/th>\n<th>xia_sum<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>ceshi<\/td>\n<td>\u4e0a\u534a\u5e74<\/td>\n<td>3<\/td>\n<td>1<\/td>\n<\/tr>\n<tr>\n<td>sss<\/td>\n<td>\u4e0b\u534a\u5e74<\/td>\n<td>0<\/td>\n<td>2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\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\u4f7f\u7528 MySQL \u67e5\u8be2\u5b9e\u73b0\u5206&#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-200198","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200198","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=200198"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200198\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200198"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200198"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200198"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}