{"id":158779,"date":"2024-11-03T04:45:37","date_gmt":"2024-11-02T20:45:37","guid":{"rendered":"https:\/\/server.hk\/cnblog\/158779\/"},"modified":"2024-11-03T04:45:38","modified_gmt":"2024-11-02T20:45:38","slug":"%e9%97%9c%e6%96%bcmysql%e7%9a%84sql%e5%84%aa%e5%8c%96%e4%b9%8b%e8%a6%86%e8%93%8b%e7%b4%a2%e5%bc%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/158779\/","title":{"rendered":"\u95dc\u65bcMySQL\u7684SQL\u512a\u5316\u4e4b\u8986\u84cb\u7d22\u5f15"},"content":{"rendered":"<h1 id=\"%e9%97%9c%e6%96%bcmysql%e7%9a%84sql%e5%84%aa%e5%8c%96%e4%b9%8b%e8%a6%86%e8%93%8b%e7%b4%a2%e5%bc%95-DhmmIUNXMw\">\u95dc\u65bcMySQL\u7684SQL\u512a\u5316\u4e4b\u8986\u84cb\u7d22\u5f15<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u6027\u80fd\u512a\u5316\u662f\u78ba\u4fdd\u61c9\u7528\u7a0b\u5e8f\u9ad8\u6548\u904b\u884c\u7684\u95dc\u9375\u56e0\u7d20\u4e4b\u4e00\u3002MySQL\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u958b\u6e90\u6578\u64da\u5eab\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u512a\u5316\u6280\u8853\uff0c\u5176\u4e2d\u8986\u84cb\u7d22\u5f15\uff08Covering Index\uff09\u662f\u4e00\u7a2e\u6709\u6548\u7684\u67e5\u8a62\u512a\u5316\u624b\u6bb5\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u8986\u84cb\u7d22\u5f15\u7684\u6982\u5ff5\u3001\u512a\u52e2\u53ca\u5176\u5728MySQL\u4e2d\u7684\u61c9\u7528\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e8%a6%86%e8%93%8b%e7%b4%a2%e5%bc%95%ef%bc%9f-DhmmIUNXMw\">\u4ec0\u9ebc\u662f\u8986\u84cb\u7d22\u5f15\uff1f<\/h2>\n<p>\u8986\u84cb\u7d22\u5f15\u662f\u6307\u4e00\u500b\u7d22\u5f15\u5305\u542b\u4e86\u67e5\u8a62\u6240\u9700\u7684\u6240\u6709\u5217\uff0c\u9019\u6a23\u5728\u57f7\u884c\u67e5\u8a62\u6642\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u76f4\u63a5\u5f9e\u7d22\u5f15\u4e2d\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\uff0c\u800c\u7121\u9700\u56de\u8868\u67e5\u8a62\u539f\u59cb\u6578\u64da\u884c\u3002\u9019\u7a2e\u65b9\u5f0f\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002<\/p>\n<h2 id=\"%e8%a6%86%e8%93%8b%e7%b4%a2%e5%bc%95%e7%9a%84%e5%84%aa%e5%8b%a2-DhmmIUNXMw\">\u8986\u84cb\u7d22\u5f15\u7684\u512a\u52e2<\/h2>\n<ul>\n<li><strong>\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\uff1a<\/strong>\u7531\u65bc\u8986\u84cb\u7d22\u5f15\u53ef\u4ee5\u907f\u514d\u56de\u8868\u67e5\u8a62\uff0c\u67e5\u8a62\u901f\u5ea6\u901a\u5e38\u6703\u986f\u8457\u63d0\u9ad8\u3002<\/li>\n<li><strong>\u6e1b\u5c11I\/O\u64cd\u4f5c\uff1a<\/strong>\u8986\u84cb\u7d22\u5f15\u6e1b\u5c11\u4e86\u5c0d\u78c1\u789f\u7684\u8b80\u53d6\u6b21\u6578\uff0c\u5f9e\u800c\u964d\u4f4e\u4e86I\/O\u64cd\u4f5c\u7684\u6210\u672c\u3002<\/li>\n<li><strong>\u512a\u5316\u8907\u96dc\u67e5\u8a62\uff1a<\/strong>\u5728\u8655\u7406\u591a\u500b\u5217\u7684\u67e5\u8a62\u6642\uff0c\u8986\u84cb\u7d22\u5f15\u53ef\u4ee5\u7c21\u5316\u67e5\u8a62\u904e\u7a0b\uff0c\u63d0\u5347\u6548\u7387\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e5%89%b5%e5%bb%ba%e8%a6%86%e8%93%8b%e7%b4%a2%e5%bc%95-DhmmIUNXMw\">\u5982\u4f55\u5275\u5efa\u8986\u84cb\u7d22\u5f15<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u5275\u5efa\u8986\u84cb\u7d22\u5f15\u7684\u904e\u7a0b\u8207\u5275\u5efa\u666e\u901a\u7d22\u5f15\u76f8\u4f3c\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u70ba\u4e00\u500b\u8868\u5275\u5efa\u8986\u84cb\u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE TABLE users (\n    id INT AUTO_INCREMENT PRIMARY KEY,\n    name VARCHAR(100),\n    email VARCHAR(100),\n    age INT\n);\n\nCREATE INDEX idx_name_email ON users (name, email);\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u70ba`users`\u8868\u5275\u5efa\u4e86\u4e00\u500b\u8986\u84cb\u7d22\u5f15`idx_name_email`\uff0c\u5b83\u5305\u542b\u4e86`name`\u548c`email`\u5169\u500b\u5217\u3002\u9019\u6a23\uff0c\u7576\u6211\u5011\u57f7\u884c\u4ee5\u4e0b\u67e5\u8a62\u6642\uff0cMySQL\u53ef\u4ee5\u76f4\u63a5\u5f9e\u7d22\u5f15\u4e2d\u7372\u53d6\u7d50\u679c\uff1a<\/p>\n<pre><code>SELECT name, email FROM users WHERE name = 'John Doe';\n<\/code><\/pre>\n<h2 id=\"%e8%a6%86%e8%93%8b%e7%b4%a2%e5%bc%95%e7%9a%84%e4%bd%bf%e7%94%a8%e5%a0%b4%e6%99%af-DhmmIUNXMw\">\u8986\u84cb\u7d22\u5f15\u7684\u4f7f\u7528\u5834\u666f<\/h2>\n<p>\u8986\u84cb\u7d22\u5f15\u7279\u5225\u9069\u5408\u4ee5\u4e0b\u5e7e\u7a2e\u60c5\u6cc1\uff1a<\/p>\n<ul>\n<li><strong>\u983b\u7e41\u67e5\u8a62\u7684\u5217\uff1a<\/strong>\u5982\u679c\u67d0\u4e9b\u5217\u7d93\u5e38\u51fa\u73fe\u5728\u67e5\u8a62\u4e2d\uff0c\u5247\u53ef\u4ee5\u8003\u616e\u70ba\u9019\u4e9b\u5217\u5275\u5efa\u8986\u84cb\u7d22\u5f15\u3002<\/li>\n<li><strong>\u7be9\u9078\u548c\u6392\u5e8f\u64cd\u4f5c\uff1a<\/strong>\u7576\u67e5\u8a62\u9700\u8981\u5c0d\u67d0\u4e9b\u5217\u9032\u884c\u7be9\u9078\u6216\u6392\u5e8f\u6642\uff0c\u8986\u84cb\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6027\u80fd\u3002<\/li>\n<li><strong>\u805a\u5408\u67e5\u8a62\uff1a<\/strong>\u5728\u9032\u884c\u805a\u5408\u64cd\u4f5c\u6642\uff0c\u8986\u84cb\u7d22\u5f15\u53ef\u4ee5\u5e6b\u52a9\u5feb\u901f\u7372\u53d6\u6240\u9700\u6578\u64da\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-DhmmIUNXMw\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u96d6\u7136\u8986\u84cb\u7d22\u5f15\u6709\u8a31\u591a\u512a\u52e2\uff0c\u4f46\u5728\u4f7f\u7528\u6642\u4e5f\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li><strong>\u7d22\u5f15\u5927\u5c0f\uff1a<\/strong>\u8986\u84cb\u7d22\u5f15\u6703\u589e\u52a0\u7d22\u5f15\u7684\u5927\u5c0f\uff0c\u904e\u591a\u7684\u7d22\u5f15\u53ef\u80fd\u6703\u5f71\u97ff\u5beb\u5165\u6027\u80fd\u3002<\/li>\n<li><strong>\u7dad\u8b77\u6210\u672c\uff1a<\/strong>\u6bcf\u7576\u8868\u4e2d\u7684\u6578\u64da\u767c\u751f\u8b8a\u66f4\u6642\uff0c\u7d22\u5f15\u4e5f\u9700\u8981\u66f4\u65b0\uff0c\u9019\u6703\u589e\u52a0\u7dad\u8b77\u6210\u672c\u3002<\/li>\n<li><strong>\u9078\u64c7\u6027\uff1a<\/strong>\u5c0d\u65bc\u4f4e\u9078\u64c7\u6027\u7684\u5217\uff0c\u8986\u84cb\u7d22\u5f15\u7684\u6548\u679c\u53ef\u80fd\u4e0d\u5982\u9810\u671f\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-DhmmIUNXMw\">\u7e3d\u7d50<\/h2>\n<p>\u8986\u84cb\u7d22\u5f15\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u67e5\u8a62\u512a\u5316\u6280\u8853\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8MySQL\u7684\u67e5\u8a62\u6027\u80fd\u3002\u901a\u904e\u5408\u7406\u5730\u8a2d\u8a08\u548c\u4f7f\u7528\u8986\u84cb\u7d22\u5f15\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u7372\u5f97\u66f4\u5feb\u7684\u97ff\u61c9\u901f\u5ea6\u3002\u7136\u800c\uff0c\u5728\u4f7f\u7528\u8986\u84cb\u7d22\u5f15\u6642\uff0c\u4e5f\u9700\u8003\u616e\u5230\u5176\u5c0d\u6027\u80fd\u7684\u5f71\u97ff\uff0c\u4ee5\u9054\u5230\u6700\u4f73\u7684\u5e73\u8861\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u5982<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a>\uff0c\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u6574\u9ad4\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u4e2d\u7684\u8986\u84cb\u7d22\u5f15\u5982\u4f55\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff0c\u6e1b\u5c11I\/O\u64cd\u4f5c\uff0c\u512a\u5316\u6578\u64da\u5eab\u6027\u80fd\uff0c\u5be6\u73fe\u66f4\u5feb\u7684\u6578\u64da\u6aa2\u7d22\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-158779","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158779","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"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=158779"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158779\/revisions"}],"predecessor-version":[{"id":158780,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158779\/revisions\/158780"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=158779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=158779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=158779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}