{"id":201086,"date":"2025-05-06T13:40:38","date_gmt":"2025-05-06T05:40:38","guid":{"rendered":"https:\/\/server.hk\/cnblog\/201086\/"},"modified":"2025-05-06T13:40:38","modified_gmt":"2025-05-06T05:40:38","slug":"mysql-%e5%85%b3%e8%81%94%e6%9f%a5%e8%af%a2%e5%88%86%e7%bb%84%e7%9b%ae%e7%9a%84%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88%e4%bd%bf%e7%94%a8-p2-product_type-p1-product_type-%e8%bf%9b%e8%a1%8c%e5%88%86","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/201086\/","title":{"rendered":"MySQL \u5173\u8054\u67e5\u8be2\u5206\u7ec4\u76ee\u7684\uff1a\u4e3a\u4ec0\u4e48\u4f7f\u7528 `p2.product_type = p1.product_type` \u8fdb\u884c\u5206\u7ec4\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

MySQL \u5173\u8054\u67e5\u8be2\u5206\u7ec4\u76ee\u7684\uff1a\u4e3a\u4ec0\u4e48\u4f7f\u7528 `p2.product_type = p1.product_type` \u8fdb\u884c\u5206\u7ec4\uff1f<\/h1>\n

\u5927\u5bb6\u597d\uff0c\u6211\u4eec\u53c8\u89c1\u9762\u4e86\u554a~\u672c\u6587\u7684\u5185\u5bb9\u4e2d\u5c06\u4f1a\u6d89\u53ca\u5230\u7b49\u7b49\u3002\u5982\u679c\u4f60\u6b63\u5728\u5b66\u4e60\u76f8\u5173\u77e5\u8bc6\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\uff0c\u4ee5\u540e\u4f1a\u7ed9\u5927\u5bb6\u5e26\u6765\u66f4\u591a\u76f8\u5173\u6587\u7ae0\uff0c\u5e0c\u671b\u6211\u4eec\u80fd\u4e00\u8d77\u8fdb\u6b65\uff01\u4e0b\u9762\u5c31\u5f00\u59cb\u672c\u6587\u7684\u6b63\u5f0f\u5185\u5bb9~<\/p>\n

<\/p>\n

MySQL \u5173\u8054\u67e5\u8be2\u4e0d\u89e3\uff1ap2.product_type = p1.product_type \u5206\u7ec4\u76ee\u7684<\/strong><\/p>\n

\u5728 MySQL \u5173\u8054\u67e5\u8be2\u4e2d\uff0c\u4f7f\u7528 FROM \u5b50\u53e5\u540e\u6307\u5b9a\u7684\u8868\u522b\u540d\u662f\u7528\u6765\u533a\u5206\u4e0d\u540c\u8868\u7684\uff0c\u5b83\u4eec\u53ef\u4ee5\u968f\u610f\u6307\u5b9a\u3002\u8fd9\u91cc\uff0cp2 \u662f product \u8868\u7684\u522b\u540d\uff0c\u53ef\u4ee5\u5c06\u5176\u7406\u89e3\u4e3a\u5bf9 product \u8868\u7684\u91cd\u547d\u540d\u3002<\/p>\n

\u81f3\u4e8e p2.product_type = p1.product_type \u6761\u4ef6\uff0c\u8fd9\u662f\u5728\u6267\u884c\u67e5\u8be2\u65f6\u7684\u8fc7\u6ee4\u6761\u4ef6\uff0c\u53ea\u5339\u914d\u6ee1\u8db3\u8be5\u6761\u4ef6\u7684\u884c\u3002\u8be5\u6761\u4ef6\u8981\u6c42 p2 \u8868\u4e2d product_type \u5217\u5fc5\u987b\u4e0e p1 \u8868\u4e2d product_type \u5217\u76f8\u7b49\u3002<\/p>\n

\u8be5\u67e5\u8be2\u8fd8\u5305\u542b GROUP BY \u5b50\u53e5\uff0c\u6309 product_type \u5217\u5bf9\u7ed3\u679c\u884c\u8fdb\u884c\u5206\u7ec4\u3002\u8fd9\u610f\u5473\u7740\u67e5\u8be2\u7ed3\u679c\u5c06\u6309 product_type \u503c\u8fdb\u884c\u6c47\u603b\uff0c\u800c\u4e0d\u662f\u6309\u5355\u4e2a product \u884c\u3002<\/p>\n

\u5206\u7ec4\u7684\u76ee\u7684\u5728\u4e8e\u805a\u5408\u6570\u636e\uff0c\u4ee5\u4fbf\u5bf9\u6bcf\u4e00\u7ec4 product_type \u503c\u8fdb\u884c\u8ba1\u7b97\u3002\u6bd4\u5982\uff0cAVG(price) \u4f1a\u8ba1\u7b97\u51fa\u6bcf\u4e00\u7ec4 product_type \u503c\u7684\u5e73\u5747\u4ef7\u683c\u3002<\/p>\n

\u4e0d\u4f7f\u7528\u5206\u7ec4\u65f6\uff0c\u67e5\u8be2\u7ed3\u679c\u7684\u5e73\u5747\u4ef7\u683c\u662f\u6240\u6709 product \u884c\u7684\u5e73\u5747\u503c\u3002\u800c\u4f7f\u7528\u5206\u7ec4\u540e\uff0c\u7ed3\u679c\u4f1a\u6309 product_type \u503c\u8fdb\u884c\u5206\u7ec4\uff0c\u518d\u5206\u522b\u8ba1\u7b97\u6bcf\u4e00\u7ec4\u7684\u5e73\u5747\u4ef7\u683c\u3002<\/p>\n

\u4ee5\u4e0a\u5c31\u662f\u300aMySQL \u5173\u8054\u67e5\u8be2\u5206\u7ec4\u76ee\u7684\uff1a\u4e3a\u4ec0\u4e48\u4f7f\u7528 `p2.product_type = p1.product_type` \u8fdb\u884c\u5206\u7ec4\uff1f\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8e\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n

\n
\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"

MySQL \u5173\u8054\u67e5\u8be2\u5206\u7ec4\u76ee\u7684\uff1a\u4e3a...<\/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-201086","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201086","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=201086"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201086\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=201086"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=201086"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=201086"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}