{"id":6663,"date":"2024-11-14T15:27:23","date_gmt":"2024-11-14T07:27:23","guid":{"rendered":"https:\/\/fwq.ai\/blog\/6663\/"},"modified":"2024-11-14T15:27:23","modified_gmt":"2024-11-14T07:27:23","slug":"group-by-%e5%90%8e%e9%9d%a2%e7%9a%84%e5%ad%97%e6%ae%b5select%e5%90%8e%e9%9d%a2%e5%bf%85%e9%a1%bb%e8%a6%81%e6%9c%89%e5%90%97","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/6663\/","title":{"rendered":"group by \u540e\u9762\u7684\u5b57\u6bb5select\u540e\u9762\u5fc5\u987b\u8981\u6709\u5417"},"content":{"rendered":"<blockquote><p>\n  \u662f\u7684\uff0cgroup by \u540e\u9762\u5b57\u6bb5 select \u540e\u9762\u5fc5\u987b\u6709\u3002\u56e0\u4e3a group by \u7528\u4e8e\u5206\u7ec4\uff0cselect \u7528\u4e8e\u9009\u62e9\u8981\u8fd4\u56de\u7684\u5217\uff0cgroup by \u67e5\u8be2\u5fc5\u987b\u5305\u542b\u805a\u5408\u51fd\u6570\u548c\u5206\u7ec4\u5217\u3002\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202409\/26\/2024092605304429661.jpg\" class=\"aligncenter\" title=\"group by \u540e\u9762\u7684\u5b57\u6bb5select\u540e\u9762\u5fc5\u987b\u8981\u6709\u5417\u63d2\u56fe\" alt=\"group by \u540e\u9762\u7684\u5b57\u6bb5select\u540e\u9762\u5fc5\u987b\u8981\u6709\u5417\u63d2\u56fe\" \/><\/p>\n<p><strong>Group By \u540e\u9762\u5b57\u6bb5 Select \u540e\u9762\u662f\u5426\u5fc5\u987b\u6709\uff1f<\/strong><\/p>\n<p><strong>\u56de\u7b54\uff1a\u662f\u7684\uff0c\u5fc5\u987b\u6709\u3002<\/strong><\/p>\n<p><strong>\u5c55\u5f00\u56de\u7b54\uff1a<\/strong><\/p>\n<p>GROUP BY \u5b50\u53e5\u7528\u4e8e\u5bf9\u6570\u636e\u96c6\u4e2d\u7684\u8bb0\u5f55\u8fdb\u884c\u5206\u7ec4\uff0c\u5c06\u5176\u6309\u67d0\u4e9b\u5217\u7684\u503c\u805a\u5408\u5728\u4e00\u8d77\u3002\u5728 GROUP BY \u5b50\u53e5\u4e2d\u6307\u5b9a\u7684\u5217\u88ab\u79f0\u4e3a\u5206\u7ec4\u5217\u3002<\/p>\n<p>SELECT \u5b50\u53e5\u7528\u4e8e\u4ece\u8868\u4e2d\u9009\u62e9\u8981\u8fd4\u56de\u7684\u5217\u3002\u5728 GROUP BY \u67e5\u8be2\u4e2d\uff0cSELECT \u5b50\u53e5\u5fc5\u987b\u5305\u542b\u4ee5\u4e0b\u5185\u5bb9\uff1a<\/p>\n<ul>\n<li> <strong>\uff1a<\/strong>\u7528\u4e8e\u5bf9\u5206\u7ec4\u5217\u7684\u503c\u8fdb\u884c\u805a\u5408\u64cd\u4f5c\uff0c\u4f8b\u5982 SUM\u3001COUNT \u6216 AVG\u3002<\/li>\n<li> <strong>\u5206\u7ec4\u5217\uff1a<\/strong>\u6307\u5b9a\u8981\u5bf9\u6570\u636e\u96c6\u8fdb\u884c\u5206\u7ec4\u7684\u5217\u3002<\/li>\n<\/ul>\n<p>\u5982\u679c SELECT \u5b50\u53e5\u4e0d\u5305\u542b\u805a\u5408\u51fd\u6570\u6216\u5206\u7ec4\u5217\uff0c\u5219\u67e5\u8be2\u5c06\u65e0\u6548\u3002<\/p>\n<p><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n<p>\u4ee5\u4e0b\u67e5\u8be2\u5bf9\u5458\u5de5\u8868\u4e2d\u7684\u90e8\u95e8\u8fdb\u884c\u5206\u7ec4\uff0c\u5e76\u8ba1\u7b97\u6bcf\u4e2a\u90e8\u95e8\u7684\u5458\u5de5\u6570\u91cf\uff1a<\/p>\n<pre>SELECT department, COUNT(*) AS employee_count\nFROM employees\nGROUP BY department;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u5728\u8fd9\u4e2a\u67e5\u8be2\u4e2d\uff1a<\/p>\n<ul>\n<li>department \u662f\u5206\u7ec4\u5217<\/li>\n<li>COUNT(*) \u662f\u805a\u5408\u51fd\u6570\uff0c\u7528\u4e8e\u8ba1\u7b97\u6bcf\u4e2a\u90e8\u95e8\u7684\u5458\u5de5\u6570\u91cf<\/li>\n<\/ul>\n<p>\u5982\u679c\u6ca1\u6709 COUNT(*) \u805a\u5408\u51fd\u6570\u6216 department \u5206\u7ec4\u5217\uff0c\u67e5\u8be2\u5c06\u65e0\u6548\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662fgroup by \u540e\u9762\u7684\u5b57\u6bb5select\u540e\u9762\u5fc5\u987b\u8981\u6709\u5417\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>\u662f\u7684\uff0cgroup by \u540e\u9762\u5b57\u6bb5 select \u540e\u9762\u5fc5\u987b\u6709\u3002\u56e0\u4e3a group by \u7528\u4e8e\u5206\u7ec4\uff0cselect \u7528\u4e8e\u9009\u62e9\u8981\u8fd4\u56de\u7684\u5217\uff0cgroup by \u67e5\u8be2\u5fc5\u987b\u5305\u542b\u805a\u5408\u51fd\u6570\u548c\u5206\u7ec4\u5217\u3002 Group By \u540e\u9762\u5b57\u6bb5 Select \u540e\u9762\u662f\u5426\u5fc5\u987b\u6709\uff1f \u56de\u7b54\uff1a\u662f\u7684\uff0c\u5fc5\u987b\u6709\u3002 \u5c55\u5f00\u56de\u7b54\uff1a GROUP BY \u5b50\u53e5\u7528\u4e8e\u5bf9\u6570\u636e\u96c6\u4e2d\u7684\u8bb0\u5f55\u8fdb\u884c\u5206\u7ec4\uff0c\u5c06\u5176\u6309\u67d0\u4e9b\u5217\u7684\u503c\u805a\u5408\u5728\u4e00\u8d77\u3002\u5728 GROUP BY \u5b50\u53e5\u4e2d\u6307\u5b9a\u7684\u5217\u88ab\u79f0\u4e3a\u5206\u7ec4\u5217\u3002 SELECT \u5b50\u53e5\u7528\u4e8e\u4ece\u8868\u4e2d\u9009\u62e9\u8981\u8fd4\u56de\u7684\u5217\u3002\u5728 GROUP BY \u67e5\u8be2\u4e2d\uff0cSELECT \u5b50\u53e5\u5fc5\u987b\u5305\u542b\u4ee5\u4e0b\u5185\u5bb9\uff1a \uff1a\u7528\u4e8e\u5bf9\u5206\u7ec4\u5217\u7684\u503c\u8fdb\u884c\u805a\u5408\u64cd\u4f5c\uff0c\u4f8b\u5982 SUM\u3001COUNT \u6216 AVG\u3002 \u5206\u7ec4\u5217\uff1a\u6307\u5b9a\u8981\u5bf9\u6570\u636e\u96c6\u8fdb\u884c\u5206\u7ec4\u7684\u5217\u3002 \u5982\u679c SELECT \u5b50\u53e5\u4e0d\u5305\u542b\u805a\u5408\u51fd\u6570\u6216\u5206\u7ec4\u5217\uff0c\u5219\u67e5\u8be2\u5c06\u65e0\u6548\u3002 \u793a\u4f8b\uff1a \u4ee5\u4e0b\u67e5\u8be2\u5bf9\u5458\u5de5\u8868\u4e2d\u7684\u90e8\u95e8\u8fdb\u884c\u5206\u7ec4\uff0c\u5e76\u8ba1\u7b97\u6bcf\u4e2a\u90e8\u95e8\u7684\u5458\u5de5\u6570\u91cf\uff1a SELECT department, COUNT(*) AS employee_count FROM employees GROUP BY department; \u767b\u5f55\u540e\u590d\u5236 \u5728\u8fd9\u4e2a\u67e5\u8be2\u4e2d\uff1a department \u662f\u5206\u7ec4\u5217 COUNT(*) [&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-6663","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6663","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=6663"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6663\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=6663"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=6663"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=6663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}