{"id":200624,"date":"2025-05-06T09:55:36","date_gmt":"2025-05-06T01:55:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200624\/"},"modified":"2025-05-06T09:55:36","modified_gmt":"2025-05-06T01:55:36","slug":"%e5%a6%82%e4%bd%95%e7%bc%96%e5%86%99-mysql-%e6%9f%a5%e8%af%a2%e4%bb%a5%e6%9f%a5%e6%89%be%e4%ba%a7%e5%93%81%e6%89%a9%e5%b1%95%e5%88%86%e7%b1%bb%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200624\/","title":{"rendered":"\u5982\u4f55\u7f16\u5199 MySQL \u67e5\u8be2\u4ee5\u67e5\u627e\u4ea7\u54c1\u6269\u5c55\u5206\u7c7b\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u7f16\u5199 MySQL \u67e5\u8be2\u4ee5\u67e5\u627e\u4ea7\u54c1\u6269\u5c55\u5206\u7c7b\uff1f<\/h1>\n<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241110\/1731203314673010f2a2678.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u5982\u4f55\u7f16\u5199 mysql \u67e5\u8be2\u4ee5\u67e5\u627e\u4ea7\u54c1\u6269\u5c55\u5206\u7c7b<\/strong><\/p>\n<p>\u5728\u8ba8\u8bba mysql \u67e5\u8be2\u7684\u7f16\u5199\u65b9\u6cd5\u4e4b\u524d\uff0c\u8ba9\u6211\u4eec\u5148\u56de\u987e\u4e00\u4e0b\u95ee\u9898\u3002\u6211\u4eec\u9700\u8981\u4ece\u4e24\u4e2a\u8868\uff08t_product \u548c t_product_category\uff09\u4e2d\u67e5\u627e\u4ea7\u54c1\uff0c\u8fd9\u4e9b\u8868\u901a\u8fc7 product_id \u548c category_id \u5217\u5173\u8054\u3002<\/p>\n<p><strong>\u89e3\u51b3\u65b9\u6848<\/strong><\/p>\n<p>\u8981\u627e\u5230\u6ee1\u8db3\u6761\u4ef6\u7684\u4ea7\u54c1\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8be2\uff1a<\/p>\n<pre>SELECT p.* \nFROM t_product AS p \nLEFT JOIN t_product_category AS pc ON p.product_id = pc.product_id \nWHERE p.category_id IN (1,2) OR pc.category_id IN (1,2) \nGROUP BY p.product_id \nORDER BY p.seq ASC, p.product_id DESC \nLIMIT 0, 20<\/pre>\n<p>\u8ba9\u6211\u4eec\u62c6\u89e3\u4e00\u4e0b\u67e5\u8be2\uff1a<\/p>\n<ul>\n<li><strong>left join<\/strong> \u6839\u636e product_id \u5217\u5c06 t_product \u548c t_product_category \u8868\u8fde\u63a5\u8d77\u6765\u3002\u8fd9\u5141\u8bb8\u6211\u4eec\u67e5\u8be2\u8fd9\u4e24\u4e2a\u8868\u4e2d\u7684\u6570\u636e\uff0c\u5373\u4f7f t_product \u4e2d\u4e0d\u5b58\u5728 category_id\u3002<\/li>\n<li><strong>where<\/strong> \u5b50\u53e5\u6307\u5b9a\u4e86\u67e5\u8be2\u6761\u4ef6\u3002\u6211\u4eec\u4f7f\u7528 in \u64cd\u4f5c\u7b26\u68c0\u67e5 p.category_id \u6216 pc.category_id \u662f\u5426\u4e0e\u7ed9\u5b9a\u7684 category_id\uff081 \u548c 2\uff09\u5339\u914d\u3002<\/li>\n<li><strong>group by p.product_id<\/strong> \u5c06\u5177\u6709\u76f8\u540c product_id \u7684\u884c\u5206\u7ec4\u5728\u4e00\u8d77\u3002<\/li>\n<li><strong>order by p.seq asc, p.product_id desc<\/strong> \u5bf9\u7ed3\u679c\u6309 seq \u5217\u5347\u5e8f\u6392\u5e8f\uff0c\u7136\u540e\u6309 product_id \u5217\u964d\u5e8f\u6392\u5e8f\u3002<\/li>\n<li><strong>limit 0, 20<\/strong> \u4ece\u7ed3\u679c\u96c6\u4e2d\u8fd4\u56de\u524d 20 \u884c\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662f\u672c\u6587\u7684\u5168\u90e8\u5185\u5bb9\u4e86\uff0c\u662f\u5426\u6709\u987a\u5229\u5e2e\u52a9\u4f60\u89e3\u51b3\u95ee\u9898\uff1f\u82e5\u662f\u80fd\u7ed9\u4f60\u5e26\u6765\u5b66\u4e60\u4e0a\u7684\u5e2e\u52a9\uff0c\u8bf7\u5927\u5bb6\u591a\u591a\u652f\u6301\u4e3b\u673a\u5b9d\u8d1d\uff01\u66f4\u591a\u5173\u4e8e\u6570\u636e\u5e93\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u4e5f\u53ef\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u3002<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u7f16\u5199 MySQL \u67e5\u8be2\u4ee5\u67e5\u627e&#46;&#46;&#46;<\/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-200624","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200624","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=200624"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200624\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200624"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200624"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200624"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}