{"id":200211,"date":"2025-05-06T12:21:04","date_gmt":"2025-05-06T04:21:04","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200211\/"},"modified":"2025-05-06T12:21:04","modified_gmt":"2025-05-06T04:21:04","slug":"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e6%9f%a5%e8%af%a2%e6%af%8f%e4%b8%aa%e4%ba%a7%e5%93%81%e5%9c%a8%e7%89%b9%e5%ae%9a%e6%97%a5%e6%9c%9f%e7%9a%84%e9%94%80%e9%87%8f%e5%b9%b6%e6%8c%89%e6%97%a5%e6%9c%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200211\/","title":{"rendered":"\u5982\u4f55\u7528 SQL \u67e5\u8be2\u6bcf\u4e2a\u4ea7\u54c1\u5728\u7279\u5b9a\u65e5\u671f\u7684\u9500\u91cf\u5e76\u6309\u65e5\u671f\u6c47\u603b\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u7528 SQL \u67e5\u8be2\u6bcf\u4e2a\u4ea7\u54c1\u5728\u7279\u5b9a\u65e5\u671f\u7684\u9500\u91cf\u5e76\u6309\u65e5\u671f\u6c47\u603b\uff1f<\/h1>\n<p>\u5077\u5077\u52aa\u529b\uff0c\u6084\u65e0\u58f0\u606f\u5730\u53d8\u5f3a\uff0c\u7136\u540e\u60ca\u8273\u6240\u6709\u4eba\uff01\u54c8\u54c8\uff0c\u5c0f\u4f19\u4f34\u4eec\u53c8\u6765\u5b66\u4e60\u5566~\u4eca\u5929\u6211\u5c06\u7ed9\u5927\u5bb6\u4ecb\u7ecd\uff0c\u8fd9\u7bc7\u6587\u7ae0\u4e3b\u8981\u4f1a\u8bb2\u5230\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u4e0d\u77e5\u9053\u5927\u5bb6\u5bf9\u5176\u90fd\u6709\u591a\u5c11\u4e86\u89e3\uff0c\u4e0b\u9762\u6211\u4eec\u5c31\u4e00\u8d77\u6765\u770b\u4e00\u5427\uff01\u5f53\u7136\uff0c\u975e\u5e38\u5e0c\u671b\u5927\u5bb6\u80fd\u591a\u591a\u8bc4\u8bba\uff0c\u7ed9\u51fa\u5408\u7406\u7684\u5efa\u8bae\uff0c\u6211\u4eec\u4e00\u8d77\u5b66\u4e60\uff0c\u4e00\u8d77\u8fdb\u6b65\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241028\/1730111432671f67c83f3da.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u5173\u4e8emysql\u4e2d\u6570\u636e\u67e5\u8be2\u57fa\u7840\u95ee\u9898\u7684\u89e3\u7b54<\/strong><\/p>\n<p><strong>\u95ee\u9898\uff1a<\/strong><\/p>\n<p>\u5982\u4f55\u6839\u636e\u7ed9\u5b9a\u8868\u683c\u4e2d\u7684\u6570\u636e\uff0c\u4f7f\u7528sql\u67e5\u8be2\u6bcf\u4e2a\u4ea7\u54c1\u5728\u7279\u5b9a\u65e5\u671f\u7684\u9500\u91cf\uff0c\u5e76\u5c06\u5176\u6309\u65e5\u671f\u6c47\u603b\uff1f<\/p>\n<p><strong>\u793a\u4f8b\u8868\u683c\uff1a<\/strong><\/p>\n<table>\n<thead>\n<tr>\n<th>\u65e5\u671f<\/th>\n<th>\u4ea7\u54c1<\/th>\n<th>\u9500\u91cf<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>2021-1-1<\/td>\n<td>a<\/td>\n<td>3<\/td>\n<\/tr>\n<tr>\n<td>2021-1-1<\/td>\n<td>b<\/td>\n<td>7<\/td>\n<\/tr>\n<tr>\n<td>2021-1-1<\/td>\n<td>a<\/td>\n<td>2<\/td>\n<\/tr>\n<tr>\n<td>2021-1-2<\/td>\n<td>b<\/td>\n<td>1<\/td>\n<\/tr>\n<tr>\n<td>2021-1-2<\/td>\n<td>a<\/td>\n<td>3<\/td>\n<\/tr>\n<tr>\n<td>2021-1-2<\/td>\n<td>b<\/td>\n<td>6<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>\u9884\u671f\u7ed3\u679c\uff1a<\/strong><\/p>\n<table>\n<thead>\n<tr>\n<th>\u4ea7\u54c1<\/th>\n<th>2021-1-1<\/th>\n<th>2021-1-2<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>a<\/td>\n<td>5<\/td>\n<td>3<\/td>\n<\/tr>\n<tr>\n<td>b<\/td>\n<td>3<\/td>\n<td>7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>\u9519\u8bef\u4ee3\u7801\u5206\u6790\uff1a<\/strong><\/p>\n<p>\u63d0\u4f9b\u7684sql\u4ee3\u7801\u9519\u8bef\u5728\u4e8e\u5b83\u4f7f\u7528\u4e86\u4e00\u4e2aleft join\uff0c\u800c\u8fd9\u5728\u6b64\u60c5\u51b5\u4e0b\u5e76\u4e0d\u9002\u7528\u3002left join\u7528\u4e8e\u8fde\u63a5\u4e24\u4e2a\u8868\uff0c\u5176\u4e2d\u4e00\u4e2a\u8868\u53ef\u4ee5\u5305\u542b\u53ef\u80fd\u4e0e\u53e6\u4e00\u4e2a\u8868\u4e2d\u4e0d\u5b58\u5728\u7684\u8bb0\u5f55\u76f8\u5173\u8054\u7684\u8bb0\u5f55\u3002\u5728\u672c\u4f8b\u4e2d\uff0c\u6ca1\u6709\u7406\u7531\u5c06\u4e24\u4e2a\u5b50\u67e5\u8be2\u8fde\u63a5\u8d77\u6765\u3002<\/p>\n<p><strong>\u6b63\u786e\u7684sql\u67e5\u8be2\uff1a<\/strong><\/p>\n<pre>SELECT\n    \u4ea7\u54c1 AS \u4ea7\u54c1\u9500\u91cf,\n    SUM(CASE\n        WHEN \u65e5\u671f = '2021-1-1' THEN \u9500\u91cf\n        ELSE 0\n    END) AS '2021-1-1',\n    SUM(CASE\n        WHEN \u65e5\u671f = '2021-1-2' THEN \u9500\u91cf\n        ELSE 0\n    END) AS '2021-1-2'\nFROM\n    mytable\nGROUP BY\n    \u4ea7\u54c1;<\/pre>\n<p>\u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300a\u5982\u4f55\u7528 SQL \u67e5\u8be2\u6bcf\u4e2a\u4ea7\u54c1\u5728\u7279\u5b9a\u65e5\u671f\u7684\u9500\u91cf\u5e76\u6309\u65e5\u671f\u6c47\u603b\uff1f\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u7528 SQL \u67e5\u8be2\u6bcf\u4e2a\u4ea7\u54c1\u5728\u7279&#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-200211","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200211","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=200211"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200211\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}