{"id":6768,"date":"2024-11-14T09:55:27","date_gmt":"2024-11-14T01:55:27","guid":{"rendered":"https:\/\/fwq.ai\/blog\/6768\/"},"modified":"2024-11-14T09:55:27","modified_gmt":"2024-11-14T01:55:27","slug":"%e5%a6%82%e4%bd%95%e5%b0%86%e5%90%8c%e4%b8%80%e5%bc%a0%e8%a1%a8%e5%86%85%e7%9a%84count-group-by%e5%92%8cselect%e8%af%ad%e5%8f%a5%e5%90%88%e5%b9%b6%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/6768\/","title":{"rendered":"\u5982\u4f55\u5c06\u540c\u4e00\u5f20\u8868\u5185\u7684COUNT GROUP BY\u548cSELECT\u8bed\u53e5\u5408\u5e76\uff1f"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/001\/246\/273\/172991214331585.jpg\" class=\"aligncenter\" title=\"\u5982\u4f55\u5c06\u540c\u4e00\u5f20\u8868\u5185\u7684COUNT GROUP BY\u548cSELECT\u8bed\u53e5\u5408\u5e76\uff1f\u63d2\u56fe\" alt=\"\u5982\u4f55\u5c06\u540c\u4e00\u5f20\u8868\u5185\u7684COUNT GROUP BY\u548cSELECT\u8bed\u53e5\u5408\u5e76\uff1f\u63d2\u56fe\" \/><\/p>\n<p><strong>\u540c\u4e00\u5f20\u8868\u5185count group by\u548cselect\u8bed\u53e5\u5408\u5e76<\/strong><\/p>\n<p>\u8981\u5408\u5e76count group by\u548cselect\u8bed\u53e5\uff0c\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u5d4c\u5957\u67e5\u8be2\u6216join\u8bed\u53e5\u3002<\/p>\n<p><strong>\u5d4c\u5957\u67e5\u8be2\u65b9\u6cd5<\/strong><\/p>\n<p>\u53ef\u4ee5\u4f7f\u7528\u5d4c\u5957\u67e5\u8be2\u7684\u65b9\u5f0f\uff0c\u5728\u5916\u90e8\u67e5\u8be2\u4e2d\u4f7f\u7528count group by\u5b50\u67e5\u8be2\u7684\u67e5\u8be2\u7ed3\u679c\u3002<\/p>\n<pre>select a,b,count(*)as count from test\nwhere (a,b) in (select a,b from test group by a,b)<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p><strong>join\u8bed\u53e5\u65b9\u6cd5<\/strong><\/p>\n<p>\u4e5f\u53ef\u4ee5\u4f7f\u7528join\u8bed\u53e5\u7684\u65b9\u5f0f\uff0c\u5c06count group by\u7684\u67e5\u8be2\u7ed3\u679c\u4e0e\u539f\u59cb\u8868join\u8d77\u6765\u3002<\/p>\n<pre>select t1.a,t1.b,t2.count\nfrom test as t1\nleft join (select a,b,count(*)as count from test group by a,b) as t2\non t1.a = t2.a and t1.b = t2.b<\/pre>\n<p>  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u5982\u4f55\u5c06\u540c\u4e00\u5f20\u8868\u5185\u7684COUNT GROUP BY\u548cSELECT\u8bed\u53e5\u5408\u5e76\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u540c\u4e00\u5f20\u8868\u5185count group by\u548cselect\u8bed\u53e5\u5408\u5e76 \u8981\u5408\u5e76count group by\u548cselect\u8bed\u53e5\uff0c\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u5d4c\u5957\u67e5\u8be2\u6216join\u8bed\u53e5\u3002 \u5d4c\u5957\u67e5\u8be2\u65b9\u6cd5 \u53ef\u4ee5\u4f7f\u7528\u5d4c\u5957\u67e5\u8be2\u7684\u65b9\u5f0f\uff0c\u5728\u5916\u90e8\u67e5\u8be2\u4e2d\u4f7f\u7528count group by\u5b50\u67e5\u8be2\u7684\u67e5\u8be2\u7ed3\u679c\u3002 select a,b,count(*)as count from test where (a,b) in (select a,b from test group by a,b) \u767b\u5f55\u540e\u590d\u5236 join\u8bed\u53e5\u65b9\u6cd5 \u4e5f\u53ef\u4ee5\u4f7f\u7528join\u8bed\u53e5\u7684\u65b9\u5f0f\uff0c\u5c06count group by\u7684\u67e5\u8be2\u7ed3\u679c\u4e0e\u539f\u59cb\u8868join\u8d77\u6765\u3002 select t1.a,t1.b,t2.count from test as t1 left join (select a,b,count(*)as count from test group by a,b) as t2 on t1.a = t2.a and t1.b = [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-6768","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6768","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=6768"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6768\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=6768"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=6768"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=6768"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}