{"id":192326,"date":"2024-11-12T18:49:25","date_gmt":"2024-11-12T10:49:25","guid":{"rendered":"https:\/\/server.hk\/cnblog\/192326\/"},"modified":"2024-11-12T18:49:26","modified_gmt":"2024-11-12T10:49:26","slug":"%e6%94%9c%e7%a8%8bsql%e4%b8%8a%e7%b7%9a%e6%b5%81%e7%a8%8b%e5%84%aa%e5%8c%96%ef%bc%8c%e5%a6%82%e4%bd%95%e5%be%9e%e6%ba%90%e9%a0%ad%e6%89%bc%e6%ae%ba%e6%85%a2%e6%9f%a5%e8%a9%a2%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/192326\/","title":{"rendered":"\u651c\u7a0bSQL\u4e0a\u7dda\u6d41\u7a0b\u512a\u5316\uff0c\u5982\u4f55\u5f9e\u6e90\u982d\u627c\u6bba\u6162\u67e5\u8a62\uff1f"},"content":{"rendered":"<h1 id=\"%e6%94%9c%e7%a8%8bsql%e4%b8%8a%e7%b7%9a%e6%b5%81%e7%a8%8b%e5%84%aa%e5%8c%96%ef%bc%8c%e5%a6%82%e4%bd%95%e5%be%9e%e6%ba%90%e9%a0%ad%e6%89%bc%e6%ae%ba%e6%85%a2%e6%9f%a5%e8%a9%a2%ef%bc%9f-HWmLJnzPYK\">\u651c\u7a0bSQL\u4e0a\u7dda\u6d41\u7a0b\u512a\u5316\uff0c\u5982\u4f55\u5f9e\u6e90\u982d\u627c\u6bba\u6162\u67e5\u8a62\uff1f<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u5546\u696d\u74b0\u5883\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u6027\u80fd\u5c0d\u65bc\u4f01\u696d\u7684\u904b\u71df\u81f3\u95dc\u91cd\u8981\u3002\u5c24\u5176\u662f\u5c0d\u65bc\u651c\u7a0b\u9019\u6a23\u7684\u65c5\u904a\u5e73\u53f0\uff0c\u5feb\u901f\u7684\u6578\u64da\u67e5\u8a62\u80fd\u5920\u76f4\u63a5\u5f71\u97ff\u7528\u6236\u9ad4\u9a57\u548c\u696d\u52d9\u6548\u7387\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u651c\u7a0b\u5728SQL\u4e0a\u7dda\u6d41\u7a0b\u4e2d\u7684\u512a\u5316\u7b56\u7565\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u6709\u6548\u7684\u65b9\u6cd5\u4f86\u5f9e\u6e90\u982d\u627c\u6bba\u6162\u67e5\u8a62\u3002<\/p>\n<h2 id=\"%e6%85%a2%e6%9f%a5%e8%a9%a2%e7%9a%84%e6%88%90%e5%9b%a0-HWmLJnzPYK\">\u6162\u67e5\u8a62\u7684\u6210\u56e0<\/h2>\n<p>\u6162\u67e5\u8a62\u901a\u5e38\u662f\u7531\u591a\u7a2e\u56e0\u7d20\u9020\u6210\u7684\uff0c\u5305\u62ec\u4f46\u4e0d\u9650\u65bc\uff1a<\/p>\n<ul>\n<li><strong>\u4e0d\u7576\u7684\u7d22\u5f15\u8a2d\u8a08\uff1a<\/strong>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u95dc\u9375\uff0c\u4f46\u904e\u591a\u6216\u4e0d\u7576\u7684\u7d22\u5f15\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\u3002<\/li>\n<li><strong>\u8907\u96dc\u7684\u67e5\u8a62\u8a9e\u53e5\uff1a<\/strong>\u904e\u65bc\u8907\u96dc\u7684SQL\u8a9e\u53e5\u53ef\u80fd\u5c0e\u81f4\u67e5\u8a62\u8a08\u5283\u4e0d\u4f73\uff0c\u5f9e\u800c\u5f71\u97ff\u57f7\u884c\u6548\u7387\u3002<\/li>\n<li><strong>\u6578\u64da\u91cf\u7684\u589e\u9577\uff1a<\/strong>\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u52a0\uff0c\u67e5\u8a62\u7684\u6027\u80fd\u53ef\u80fd\u6703\u53d7\u5230\u5f71\u97ff\uff0c\u7279\u5225\u662f\u5728\u6c92\u6709\u9069\u7576\u512a\u5316\u7684\u60c5\u6cc1\u4e0b\u3002<\/li>\n<li><strong>\u786c\u9ad4\u8cc7\u6e90\u4e0d\u8db3\uff1a<\/strong>\u4f3a\u670d\u5668\u7684CPU\u3001\u5167\u5b58\u548c\u78c1\u789fI\/O\u7b49\u8cc7\u6e90\u4e0d\u8db3\u4e5f\u6703\u5c0e\u81f4\u67e5\u8a62\u901f\u5ea6\u8b8a\u6162\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%84%aa%e5%8c%96sql%e6%9f%a5%e8%a9%a2%e7%9a%84%e7%ad%96%e7%95%a5-HWmLJnzPYK\">\u512a\u5316SQL\u67e5\u8a62\u7684\u7b56\u7565<\/h2>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8%e9%81%a9%e7%95%b6%e7%9a%84%e7%b4%a2%e5%bc%95-HWmLJnzPYK\">1. \u4f7f\u7528\u9069\u7576\u7684\u7d22\u5f15<\/h3>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u6709\u6548\u5de5\u5177\u3002\u651c\u7a0b\u53ef\u4ee5\u901a\u904e\u5206\u6790\u67e5\u8a62\u65e5\u8a8c\u4f86\u8b58\u5225\u6700\u5e38\u7528\u7684\u67e5\u8a62\uff0c\u4e26\u91dd\u5c0d\u9019\u4e9b\u67e5\u8a62\u5275\u5efa\u5408\u9069\u7684\u7d22\u5f15\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>CREATE INDEX idx_user_id ON orders(user_id);<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u7d22\u5f15\u53ef\u4ee5\u52a0\u901f\u57fa\u65bc\u7528\u6236ID\u7684\u67e5\u8a62\u3002<\/p>\n<h3 id=\"2-%e7%b0%a1%e5%8c%96%e6%9f%a5%e8%a9%a2%e8%aa%9e%e5%8f%a5-HWmLJnzPYK\">2. \u7c21\u5316\u67e5\u8a62\u8a9e\u53e5<\/h3>\n<p>\u8907\u96dc\u7684\u67e5\u8a62\u8a9e\u53e5\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u554f\u984c\u3002\u651c\u7a0b\u61c9\u8a72\u5b9a\u671f\u5be9\u67e5\u548c\u91cd\u69cbSQL\u8a9e\u53e5\uff0c\u78ba\u4fdd\u5b83\u5011\u7c21\u6f54\u660e\u4e86\u3002\u4f8b\u5982\uff0c\u907f\u514d\u4f7f\u7528\u4e0d\u5fc5\u8981\u7684\u5b50\u67e5\u8a62\uff0c\u6539\u7528JOIN\u64cd\u4f5c\uff1a<\/p>\n<pre><code>SELECT o.order_id, u.username \nFROM orders o \nJOIN users u ON o.user_id = u.id;<\/code><\/pre>\n<h3 id=\"3-%e5%ae%9a%e6%9c%9f%e9%80%b2%e8%a1%8c%e6%95%b8%e6%93%9a%e5%ba%ab%e7%b6%ad%e8%ad%b7-HWmLJnzPYK\">3. \u5b9a\u671f\u9032\u884c\u6578\u64da\u5eab\u7dad\u8b77<\/h3>\n<p>\u5b9a\u671f\u7684\u6578\u64da\u5eab\u7dad\u8b77\u53ef\u4ee5\u5e6b\u52a9\u651c\u7a0b\u4fdd\u6301\u826f\u597d\u7684\u6027\u80fd\u3002\u9019\u5305\u62ec\u91cd\u5efa\u7d22\u5f15\u3001\u66f4\u65b0\u7d71\u8a08\u4fe1\u606f\u548c\u6e05\u7406\u904e\u671f\u6578\u64da\u3002\u9019\u4e9b\u64cd\u4f5c\u53ef\u4ee5\u6e1b\u5c11\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\uff0c\u4e26\u63d0\u9ad8\u6574\u9ad4\u6027\u80fd\u3002<\/p>\n<h3 id=\"4-%e7%9b%a3%e6%8e%a7%e5%92%8c%e5%88%86%e6%9e%90%e6%9f%a5%e8%a9%a2%e6%80%a7%e8%83%bd-HWmLJnzPYK\">4. \u76e3\u63a7\u548c\u5206\u6790\u67e5\u8a62\u6027\u80fd<\/h3>\n<p>\u4f7f\u7528\u6578\u64da\u5eab\u6027\u80fd\u76e3\u63a7\u5de5\u5177\u53ef\u4ee5\u5e6b\u52a9\u651c\u7a0b\u53ca\u6642\u767c\u73fe\u6162\u67e5\u8a62\u554f\u984c\u3002\u901a\u904e\u5206\u6790\u67e5\u8a62\u57f7\u884c\u8a08\u5283\uff0c\u651c\u7a0b\u53ef\u4ee5\u627e\u51fa\u6027\u80fd\u74f6\u9838\u4e26\u9032\u884c\u91dd\u5c0d\u6027\u512a\u5316\u3002\u4f8b\u5982\uff0c\u4f7f\u7528EXPLAIN\u547d\u4ee4\u4f86\u67e5\u770b\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff1a<\/p>\n<pre><code>EXPLAIN SELECT * FROM orders WHERE user_id = 1;<\/code><\/pre>\n<h2 id=\"%e7%b5%90%e8%ab%96-HWmLJnzPYK\">\u7d50\u8ad6<\/h2>\n<p>\u5728\u651c\u7a0b\u7684SQL\u4e0a\u7dda\u6d41\u7a0b\u4e2d\uff0c\u512a\u5316\u67e5\u8a62\u6027\u80fd\u662f\u63d0\u5347\u7528\u6236\u9ad4\u9a57\u7684\u95dc\u9375\u3002\u901a\u904e\u5408\u7406\u8a2d\u8a08\u7d22\u5f15\u3001\u7c21\u5316\u67e5\u8a62\u8a9e\u53e5\u3001\u5b9a\u671f\u7dad\u8b77\u6578\u64da\u5eab\u4ee5\u53ca\u6301\u7e8c\u76e3\u63a7\u67e5\u8a62\u6027\u80fd\uff0c\u651c\u7a0b\u53ef\u4ee5\u6709\u6548\u5730\u5f9e\u6e90\u982d\u627c\u6bba\u6162\u67e5\u8a62\uff0c\u78ba\u4fdd\u7cfb\u7d71\u7684\u9ad8\u6548\u904b\u884c\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc\u5982\u4f55\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\u7684\u8cc7\u8a0a\uff0c\u60a8\u53ef\u4ee5\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\uff0c\u63a2\u7d22\u6211\u5011\u7684<a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u9019\u4e9b\u89e3\u6c7a\u65b9\u6848\u80fd\u5920\u70ba\u60a8\u7684\u696d\u52d9\u63d0\u4f9b\u7a69\u5b9a\u548c\u9ad8\u6548\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22\u651c\u7a0bSQL\u4e0a\u7dda\u6d41\u7a0b\u512a\u5316\uff0c\u5b78\u7fd2\u5982\u4f55\u5f9e\u6e90\u982d\u89e3\u6c7a\u6162\u67e5\u8a62\u554f\u984c\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\u8207\u7cfb\u7d71\u6027\u80fd\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-192326","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/192326","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=192326"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/192326\/revisions"}],"predecessor-version":[{"id":192327,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/192326\/revisions\/192327"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=192326"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=192326"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=192326"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}