{"id":5180,"date":"2024-11-14T10:36:43","date_gmt":"2024-11-14T02:36:43","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5180\/"},"modified":"2024-11-14T10:36:43","modified_gmt":"2024-11-14T02:36:43","slug":"sql%e4%b8%adgroup-by%e7%94%a8%e6%b3%95","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5180\/","title":{"rendered":"sql\u4e2dgroup by\u7528\u6cd5"},"content":{"rendered":"

\n group by \u6839\u636e\u5217\u503c\u5206\u7ec4\u6570\u636e\uff0c\u5e76\u5bf9\u6bcf\u7ec4\u5e94\u7528\u805a\u5408\u51fd\u6570\uff08\u5982 sum\u3001count\u3001avg\uff09\u3002\u5b83\u5e38\u7528\u4e8e\u6c47\u603b\u6570\u636e\u3001\u67e5\u627e\u6a21\u5f0f\u548c\u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7c7b\u3002\u5177\u4f53\u6b65\u9aa4\u5305\u62ec\uff1a1. \u6307\u5b9a\u8981\u5206\u7ec4\u7684\u5217\uff1b2. \u9009\u62e9\u8981\u6267\u884c\u7684\u805a\u5408\u51fd\u6570\uff1b3. \u5e94\u7528 group by \u5b50\u53e5\u5206\u7ec4\u6570\u636e\u3002\n<\/p><\/blockquote>\n

\"sql\u4e2dgroup<\/p>\n

SQL \u4e2d GROUP BY \u7528\u6cd5<\/strong><\/p>\n

\u4ec0\u4e48\u662f GROUP BY\uff1f<\/strong><\/p>\n

GROUP BY \u662f SQL \u4e2d\u7528\u4e8e\u6839\u636e\u4e00\u4e2a\u6216\u591a\u4e2a\u5217\u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7ec4\u7684\u547d\u4ee4\u3002\u5b83\u5c06\u5177\u6709\u76f8\u540c\u503c\u7684\u884c\u5206\u7ec4\u5230\u4e00\u8d77\uff0c\u5e76\u5bf9\u6bcf\u7ec4\u6570\u636e\u8ba1\u7b97\uff08\u5982 SUM\u3001COUNT\u3001AVG\uff09\u3002<\/p>\n

\u8bed\u6cd5<\/strong><\/p>\n

SELECT \u5217, \u805a\u5408\u51fd\u6570(\u5217)\nFROM \u8868\nGROUP BY \u5217<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
    \n
  •  \u5217\uff1a<\/strong>\u8981\u5206\u7ec4\u7684\u5217\u6216\u5217\u5217\u8868\u3002<\/li>\n
  •  \u805a\u5408\u51fd\u6570\uff1a<\/strong>\u5bf9\u5206\u7ec4\u6570\u636e\u6267\u884c\u7684\u51fd\u6570\uff0c\u5982 SUM\u3001COUNT\u3001AVG\u3002<\/li>\n<\/ul>\n
    \u4f7f\u7528\u573a\u666f<\/strong><\/p>\n
    GROUP BY \u5e38\u7528\u4e8e\u4ee5\u4e0b\u573a\u666f\uff1a<\/p>\n
      \n
    • \u6c47\u603b\u6570\u636e\uff08\u5982\u8ba1\u7b97\u603b\u548c\u3001\u8ba1\u6570\u3001\u5e73\u5747\u503c\uff09<\/li>\n
    • \u67e5\u627e\u6a21\u5f0f\u548c\u8d8b\u52bf<\/li>\n
    • \u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7c7b\u548c\u7ec6\u5206<\/li>\n<\/ul>\n
      \u8be6\u7ec6\u89e3\u91ca<\/strong><\/p>\n
        \n
      •  \u5206\u7ec4\uff1a<\/strong>GROUP BY \u5c06\u5177\u6709\u76f8\u540c\u503c\u7684\u884c\u5206\u7ec4\u5230\u4e00\u8d77\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8be2\u5c06\u5458\u5de5\u6570\u636e\u6309\u90e8\u95e8\u5206\u7ec4\uff1a<\/li>\n<\/ul>\n
        SELECT \u90e8\u95e8, SUM(\u5de5\u8d44)\nFROM \u5458\u5de5\nGROUP BY \u90e8\u95e8<\/pre>\n
         \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
          \n
        •  \u805a\u5408\uff1a<\/strong>GROUP BY \u5141\u8bb8\u5bf9\u6bcf\u7ec4\u6570\u636e\u6267\u884c\u805a\u5408\u51fd\u6570\u3002\u4f8b\u5982\uff0c\u4e0a\u4e00\u4e2a\u67e5\u8be2\u8ba1\u7b97\u4e86\u6bcf\u4e2a\u90e8\u95e8\u7684\u5de5\u8d44\u603b\u989d\u3002<\/li>\n
        •  \u591a\u4e2a\u5206\u7ec4\u5217\uff1a<\/strong>GROUP BY \u53ef\u4ee5\u4f7f\u7528\u591a\u4e2a\u5217\u8fdb\u884c\u5206\u7ec4\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8be2\u6309\u90e8\u95e8\u548c\u804c\u4f4d\u5206\u7ec4\uff1a<\/li>\n<\/ul>\n
          SELECT \u90e8\u95e8, \u804c\u4f4d, SUM(\u5de5\u8d44)\nFROM \u5458\u5de5\nGROUP BY \u90e8\u95e8, \u804c\u4f4d<\/pre>\n
           \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
            \n
          •  \u5d4c\u5957\u7684 GROUP BY\uff1a<\/strong>GROUP BY \u53ef\u4ee5\u5d4c\u5957\u4f7f\u7528\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8be2\u6309\u90e8\u95e8\u5206\u7ec4\uff0c\u518d\u6309\u804c\u4f4d\u5206\u7ec4\uff1a<\/li>\n<\/ul>\n
            SELECT \u90e8\u95e8, \u804c\u4f4d, SUM(\u5de5\u8d44)\nFROM \u5458\u5de5\nGROUP BY \u90e8\u95e8\nGROUP BY \u804c\u4f4d<\/pre>\n
             \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
            \u6ce8\u610f\uff1a<\/strong><\/p>\n
              \n
            • \u5728\u4f7f\u7528 GROUP BY \u65f6\uff0c\u5fc5\u987b\u5728 SELECT \u8bed\u53e5\u4e2d\u5305\u542b\u5206\u7ec4\u5217\u3002<\/li>\n
            • \u805a\u5408\u51fd\u6570\u53ea\u80fd\u5e94\u7528\u4e8e\u5206\u7ec4\u5217\u6216\u805a\u5408\u51fd\u6570\u7684\u7ed3\u679c\u3002<\/li>\n<\/ul>\n
              \u4ee5\u4e0a\u5c31\u662fsql\u4e2dgroup by\u7528\u6cd5\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":"
              group by \u6839\u636e\u5217\u503c\u5206\u7ec4\u6570\u636e\uff0c\u5e76\u5bf9\u6bcf\u7ec4\u5e94\u7528\u805a\u5408\u51fd\u6570\uff08\u5982 sum\u3001count\u3001avg\uff09\u3002\u5b83\u5e38\u7528\u4e8e\u6c47\u603b\u6570\u636e\u3001\u67e5\u627e\u6a21\u5f0f\u548c\u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7c7b\u3002\u5177\u4f53\u6b65\u9aa4\u5305\u62ec\uff1a1. \u6307\u5b9a\u8981\u5206\u7ec4\u7684\u5217\uff1b2. \u9009\u62e9\u8981\u6267\u884c\u7684\u805a\u5408\u51fd\u6570\uff1b3. \u5e94\u7528 group by \u5b50\u53e5\u5206\u7ec4\u6570\u636e\u3002 SQL \u4e2d GROUP BY \u7528\u6cd5 \u4ec0\u4e48\u662f GROUP BY\uff1f GROUP BY \u662f SQL \u4e2d\u7528\u4e8e\u6839\u636e\u4e00\u4e2a\u6216\u591a\u4e2a\u5217\u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7ec4\u7684\u547d\u4ee4\u3002\u5b83\u5c06\u5177\u6709\u76f8\u540c\u503c\u7684\u884c\u5206\u7ec4\u5230\u4e00\u8d77\uff0c\u5e76\u5bf9\u6bcf\u7ec4\u6570\u636e\u8ba1\u7b97\uff08\u5982 SUM\u3001COUNT\u3001AVG\uff09\u3002 \u8bed\u6cd5 SELECT \u5217, \u805a\u5408\u51fd\u6570(\u5217) FROM \u8868 GROUP BY \u5217 \u767b\u5f55\u540e\u590d\u5236 \u5217\uff1a\u8981\u5206\u7ec4\u7684\u5217\u6216\u5217\u5217\u8868\u3002 \u805a\u5408\u51fd\u6570\uff1a\u5bf9\u5206\u7ec4\u6570\u636e\u6267\u884c\u7684\u51fd\u6570\uff0c\u5982 SUM\u3001COUNT\u3001AVG\u3002 \u4f7f\u7528\u573a\u666f GROUP BY \u5e38\u7528\u4e8e\u4ee5\u4e0b\u573a\u666f\uff1a \u6c47\u603b\u6570\u636e\uff08\u5982\u8ba1\u7b97\u603b\u548c\u3001\u8ba1\u6570\u3001\u5e73\u5747\u503c\uff09 \u67e5\u627e\u6a21\u5f0f\u548c\u8d8b\u52bf \u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7c7b\u548c\u7ec6\u5206 \u8be6\u7ec6\u89e3\u91ca \u5206\u7ec4\uff1aGROUP BY \u5c06\u5177\u6709\u76f8\u540c\u503c\u7684\u884c\u5206\u7ec4\u5230\u4e00\u8d77\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8be2\u5c06\u5458\u5de5\u6570\u636e\u6309\u90e8\u95e8\u5206\u7ec4\uff1a SELECT \u90e8\u95e8, SUM(\u5de5\u8d44) FROM \u5458\u5de5 GROUP BY […]<\/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-5180","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5180","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=5180"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5180\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5180"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5180"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}