{"id":200315,"date":"2025-05-06T08:15:48","date_gmt":"2025-05-06T00:15:48","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200315\/"},"modified":"2025-05-06T08:15:48","modified_gmt":"2025-05-06T00:15:48","slug":"%e4%b8%ba%e4%bb%80%e4%b9%88-mysql-%e8%81%94%e5%90%88%e7%b4%a2%e5%bc%95%e5%bf%85%e9%a1%bb%e6%bb%a1%e8%b6%b3%e6%9c%80%e5%b7%a6%e5%89%8d%e7%bc%80%e5%8e%9f%e5%88%99%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200315\/","title":{"rendered":"\u4e3a\u4ec0\u4e48 MySQL \u8054\u5408\u7d22\u5f15\u5fc5\u987b\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u539f\u5219\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u4e3a\u4ec0\u4e48 MySQL \u8054\u5408\u7d22\u5f15\u5fc5\u987b\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u539f\u5219\uff1f<\/h1>\n<p>\u6570\u636e\u5e93\u5c0f\u767d\u4e00\u679a\uff0c\u6b63\u5728\u4e0d\u65ad\u5b66\u4e60\u79ef\u7d2f\u77e5\u8bc6\uff0c\u73b0\u5c06\u5b66\u4e60\u5230\u7684\u77e5\u8bc6\u8bb0\u5f55\u4e00\u4e0b\uff0c\u4e5f\u662f\u5c06\u6211\u7684\u6240\u5f97\u5206\u4eab\u7ed9\u5927\u5bb6\uff01\u800c\u4eca\u5929\u8fd9\u7bc7\u6587\u7ae0\u300a\u4e3a\u4ec0\u4e48 MySQL \u8054\u5408\u7d22\u5f15\u5fc5\u987b\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u539f\u5219\uff1f\u300b\u5e26\u5927\u5bb6\u6765\u4e86\u89e3\u4e00\u4e0b##content_title##\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u4ece\u800c\u5f25\u8865\u81ea\u5df1\u7684\u4e0d\u8db3\uff0c\u52a9\u529b\u5b9e\u6218\u5f00\u53d1\uff01<\/p>\n<p><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241101\/173044909667248ec89ea19.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>MySQL \u4e2d\u6700\u5de6\u524d\u7f00\u8981\u6c42\u7684\u5fc5\u8981\u6027<\/strong><\/p>\n<p><strong>\u95ee\u9898\uff1a<\/strong><\/p>\n<p>MySQL \u4e2d\u8054\u5408\u7d22\u5f15\u6709\u6700\u5de6\u524d\u7f00\u7684\u8981\u6c42\uff0c\u5373\u9700\u8981\u67e5\u8be2\u6700\u5de6\u8fb9\u7684\u5217\u624d\u80fd\u4f7f\u7528\u7d22\u5f15\u3002\u4f18\u5316\u5668\u4e3a\u4ec0\u4e48\u4e0d\u80fd\u81ea\u52a8\u8c03\u6574\u987a\u5e8f\uff0c\u4f7f\u5f97\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u6761\u4ef6\uff1f<\/p>\n<p><strong>\u56de\u7b54\uff1a<\/strong><\/p>\n<p>\u5bf9\u6700\u5de6\u524d\u7f00\u7684\u7406\u89e3\u6709\u8bef\u3002<\/p>\n<p>\u5982 index(&#8216;user_id&#8217;, &#8216;created_at&#8217;) \u7d22\u5f15\uff0c\u867d\u7136\u67e5\u8be2\u4e2d created_at \u6392\u5728\u6700\u5de6\uff0c\u4f46 user_id \u540c\u6837\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u6761\u4ef6\uff0c\u56e0\u4e3a user_id \u4f4d\u4e8e\u7d22\u5f15\u7684\u6700\u5de6\u8fb9\u3002<\/p>\n<p><strong>\u6700\u5de6\u524d\u7f00\u89c4\u5219\u5982\u4e0b\uff1a<\/strong><\/p>\n<ul>\n<li>\u4f7f\u7528\u7d22\u5f15\u7684\u67e5\u8be2\u6761\u4ef6\u4e2d\uff0c\u9996\u5217\u5fc5\u987b\u51fa\u73b0\u5728\u8054\u5408\u7d22\u5f15\u7684\u6700\u5de6\u8fb9\u3002<\/li>\n<li>\u540e\u7eed\u5217\u53ef\u4ee5\u4efb\u610f\u6392\u5217\uff0c\u53ea\u8981\u6ee1\u8db3\u7b2c\u4e00\u4e2a\u89c4\u5219\u5373\u53ef\u3002<\/li>\n<\/ul>\n<p><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n<p>\u8054\u5408\u7d22\u5f15 (a, b, c) \u7684\u67e5\u8be2\u793a\u4f8b\uff1a<\/p>\n<ul>\n<li>where a, b, c<\/li>\n<li>where a, c<\/li>\n<li>where a, b<\/li>\n<li>where a<\/li>\n<\/ul>\n<p>\u53ea\u6709\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u7684\u67e5\u8be2\u624d\u80fd\u8d70\u7d22\u5f15\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li>where b, c \u4e0d\u80fd\u8d70\u7d22\u5f15\uff08\u56e0\u4e3a a \u672a\u51fa\u73b0\uff09<\/li>\n<\/ul>\n<p><strong>\u6ce8\u610f\uff1a<\/strong><\/p>\n<ul>\n<li>where \u5b50\u53e5\u4e2d\u5217\u7684\u987a\u5e8f\u53ef\u4ee5\u4efb\u610f\u7ec4\u5408\uff0c\u4f46\u987b\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u89c4\u5219\u3002<\/li>\n<li>order \u5b50\u53e5\u4e2d\uff0c\u9996\u5217\u4e5f\u5fc5\u987b\u6ee1\u8db3\u6700\u5de6\u524d\u7f00\u6761\u4ef6\u3002<\/li>\n<\/ul>\n<p>\u4eca\u5929\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u5e0c\u671b\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff1b\u5173\u4e8e\u6570\u636e\u5e93\u7684\u6280\u672f\u77e5\u8bc6\u6211\u4eec\u4f1a\u4e00\u70b9\u70b9\u6df1\u5165\u4ecb\u7ecd\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u4e00\u8d77\u5b66\u4e60\u7f16\u7a0b~<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u4e3a\u4ec0\u4e48 MySQL \u8054\u5408\u7d22\u5f15\u5fc5\u987b&#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-200315","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200315","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=200315"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200315\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200315"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200315"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200315"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}