{"id":27928,"date":"2024-11-24T09:40:29","date_gmt":"2024-11-24T01:40:29","guid":{"rendered":"https:\/\/fwq.ai\/blog\/27928\/"},"modified":"2024-11-24T09:40:29","modified_gmt":"2024-11-24T01:40:29","slug":"mysql-%e5%85%b3%e8%81%94%e6%9f%a5%e8%af%a2%e4%b8%ad%ef%bc%8c%e5%88%86%e7%bb%84%e5%92%8c%e5%88%ab%e5%90%8d%e5%a6%82%e4%bd%95%e5%b8%ae%e5%8a%a9%e6%88%91%e4%bb%ac%e6%9b%b4%e6%b7%b1%e5%85%a5%e5%9c%b0-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/27928\/","title":{"rendered":"MySQL \u5173\u8054\u67e5\u8be2\u4e2d\uff0c\u5206\u7ec4\u548c\u522b\u540d\u5982\u4f55\u5e2e\u52a9\u6211\u4eec\u66f4\u6df1\u5165\u5730\u5206\u6790\u6570\u636e\uff1f"},"content":{"rendered":"

\"MySQL<\/p>\n

MySQL \u5173\u8054\u67e5\u8be2\u4e2d\u7684\u5206\u7ec4\u548c\u522b\u540d<\/strong><\/p>\n

\u5728 MySQL \u5173\u8054\u67e5\u8be2\u4e2d\uff0c\u7ecf\u5e38\u4f1a\u9047\u5230 FROM \u5173\u952e\u5b57\u540e\u4f7f\u7528\u8868\u522b\u540d\u7684\u60c5\u51b5\uff0c\u4f8b\u5982 FROM product AS p2 \u4e2d\u7684 p2 \u5373\u4e3a\u8868\u522b\u540d\u3002\u522b\u540d\u5141\u8bb8\u6211\u4eec\u5c06\u8868\u7684\u540d\u5b57\u7b80\u79f0\u4e3a\u4e00\u4e2a\u66f4\u6613\u4e8e\u5904\u7406\u7684\u540d\u79f0\uff0c\u5728\u5173\u8054\u67e5\u8be2\u4e2d\u5c24\u5176\u6709\u7528\u3002<\/p>\n

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\u9664\u6b64\u4e4b\u5916\uff0c\u67e5\u8be2\u8fd8\u4f7f\u7528\u4e86 GROUP BY \u5b50\u53e5\uff0c\u8be5\u5b50\u53e5\u6309\u7167 product_type \u5206\u7ec4\u3002\u8fd9\u610f\u5473\u7740\u67e5\u8be2\u5c06\u8fd4\u56de\u6bcf\u4e2a\u552f\u4e00 product_type \u7684\u805a\u5408\u7ed3\u679c\uff08\u4f8b\u5982\uff0c\u6bcf\u4e2a product_type \u7684\u5e73\u5747 quantity\uff09\u3002<\/p>\n

\u4e0d\u4f7f\u7528 GROUP BY\uff0c\u67e5\u8be2\u5c06\u8ba1\u7b97\u6240\u6709\u884c\u7684\u5e73\u5747 quantity\u3002\u901a\u8fc7\u5206\u7ec4\uff0c\u6211\u4eec\u53ef\u4ee5\u8ba1\u7b97\u51fa\u6309 product_type \u7ec6\u5206\u7684\u5e73\u5747 quantity\uff0c\u4ece\u800c\u83b7\u5f97\u66f4\u8be6\u7ec6\u548c\u6709\u610f\u4e49\u7684\u7ed3\u679c\u3002<\/p>\n

\u4ee5\u4e0a\u5c31\u662fMySQL \u5173\u8054\u67e5\u8be2\u4e2d\uff0c\u5206\u7ec4\u548c\u522b\u540d\u5982\u4f55\u5e2e\u52a9\u6211\u4eec\u66f4\u6df1\u5165\u5730\u5206\u6790\u6570\u636e\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"

MySQL \u5173\u8054\u67e5\u8be2\u4e2d\u7684\u5206\u7ec4\u548c\u522b\u540d \u5728 MySQL \u5173\u8054\u67e5\u8be2\u4e2d\uff0c\u7ecf\u5e38\u4f1a\u9047\u5230 FROM \u5173\u952e\u5b57\u540e\u4f7f\u7528\u8868\u522b\u540d\u7684\u60c5\u51b5\uff0c\u4f8b\u5982 FROM product AS p2 \u4e2d\u7684 p2 \u5373\u4e3a\u8868\u522b\u540d\u3002\u522b\u540d\u5141\u8bb8\u6211\u4eec\u5c06\u8868\u7684\u540d\u5b57\u7b80\u79f0\u4e3a\u4e00\u4e2a\u66f4\u6613\u4e8e\u5904\u7406\u7684\u540d\u79f0\uff0c\u5728\u5173\u8054\u67e5\u8be2\u4e2d\u5c24\u5176\u6709\u7528\u3002 \u672c\u4f8b\u4e2d\uff0cp2.product_type = p1.product_type \u662f\u5173\u8054\u6761\u4ef6\uff0c\u7528\u4e8e\u8fde\u63a5 product \u8868\uff08\u4f7f\u7528\u522b\u540d p1\uff09\u548c product \u8868\u7684\u53e6\u4e00\u4e2a\u5b9e\u4f8b\uff08\u4f7f\u7528\u522b\u540d p2\uff09\u3002\u8fd9\u4e2a\u6761\u4ef6\u786e\u4fdd\u53ea\u6709\u5f53\u4e24\u4e2a\u8868\u4e2d\u7684 product_type \u503c\u76f8\u540c\u65f6\uff0c\u624d\u4f1a\u4ea7\u751f\u5339\u914d\u3002 \u9664\u6b64\u4e4b\u5916\uff0c\u67e5\u8be2\u8fd8\u4f7f\u7528\u4e86 GROUP BY \u5b50\u53e5\uff0c\u8be5\u5b50\u53e5\u6309\u7167 product_type \u5206\u7ec4\u3002\u8fd9\u610f\u5473\u7740\u67e5\u8be2\u5c06\u8fd4\u56de\u6bcf\u4e2a\u552f\u4e00 product_type \u7684\u805a\u5408\u7ed3\u679c\uff08\u4f8b\u5982\uff0c\u6bcf\u4e2a product_type \u7684\u5e73\u5747 quantity\uff09\u3002 \u4e0d\u4f7f\u7528 GROUP BY\uff0c\u67e5\u8be2\u5c06\u8ba1\u7b97\u6240\u6709\u884c\u7684\u5e73\u5747 quantity\u3002\u901a\u8fc7\u5206\u7ec4\uff0c\u6211\u4eec\u53ef\u4ee5\u8ba1\u7b97\u51fa\u6309 product_type \u7ec6\u5206\u7684\u5e73\u5747 quantity\uff0c\u4ece\u800c\u83b7\u5f97\u66f4\u8be6\u7ec6\u548c\u6709\u610f\u4e49\u7684\u7ed3\u679c\u3002 \u4ee5\u4e0a\u5c31\u662fMySQL \u5173\u8054\u67e5\u8be2\u4e2d\uff0c\u5206\u7ec4\u548c\u522b\u540d\u5982\u4f55\u5e2e\u52a9\u6211\u4eec\u66f4\u6df1\u5165\u5730\u5206\u6790\u6570\u636e\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/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-27928","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/27928","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=27928"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/27928\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=27928"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=27928"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=27928"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}