{"id":61395,"date":"2024-10-13T10:48:18","date_gmt":"2024-10-13T02:48:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/61395\/"},"modified":"2024-10-13T10:48:18","modified_gmt":"2024-10-13T02:48:18","slug":"explain%e9%80%b2%e8%a1%8c%e7%b4%a2%e5%bc%95%e5%88%86%e6%9e%90%e5%92%8c%e5%84%aa%e5%8c%96","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/61395\/","title":{"rendered":"Explain\u9032\u884c\u7d22\u5f15\u5206\u6790\u548c\u512a\u5316"},"content":{"rendered":"<h1 id=\"%e9%80%b2%e8%a1%8c%e7%b4%a2%e5%bc%95%e5%88%86%e6%9e%90%e5%92%8c%e5%84%aa%e5%8c%96-nCgXlrnQsR\">\u9032\u884c\u7d22\u5f15\u5206\u6790\u548c\u512a\u5316<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u95dc\u9375\u56e0\u7d20\u4e4b\u4e00\u3002\u7d22\u5f15\u7684\u4f5c\u7528\u985e\u4f3c\u65bc\u66f8\u7c4d\u7684\u76ee\u9304\uff0c\u80fd\u5920\u5e6b\u52a9\u6578\u64da\u5eab\u5feb\u901f\u5b9a\u4f4d\u6240\u9700\u7684\u6578\u64da\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u7d22\u5f15\u7684\u5206\u6790\u548c\u512a\u5316\u65b9\u6cd5\uff0c\u5e6b\u52a9\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u548c\u958b\u767c\u8005\u63d0\u5347\u7cfb\u7d71\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e7%b4%a2%e5%bc%95%ef%bc%9f-nCgXlrnQsR\">\u4ec0\u9ebc\u662f\u7d22\u5f15\uff1f<\/h2>\n<p>\u7d22\u5f15\u662f\u4e00\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u65e8\u5728\u52a0\u901f\u6578\u64da\u6aa2\u7d22\u3002\u5b83\u901a\u5e38\u7531\u4e00\u500b\u6216\u591a\u500b\u5217\u7d44\u6210\uff0c\u4e26\u4e14\u53ef\u4ee5\u662f\u552f\u4e00\u7684\u6216\u975e\u552f\u4e00\u7684\u3002\u7d22\u5f15\u7684\u985e\u578b\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong>B\u6a39\u7d22\u5f15<\/strong>\uff1a\u6700\u5e38\u898b\u7684\u7d22\u5f15\u985e\u578b\uff0c\u9069\u7528\u65bc\u7bc4\u570d\u67e5\u8a62\u3002<\/li>\n<li><strong>\u54c8\u5e0c\u7d22\u5f15<\/strong>\uff1a\u9069\u5408\u7cbe\u78ba\u67e5\u8a62\uff0c\u4f46\u4e0d\u652f\u6301\u7bc4\u570d\u67e5\u8a62\u3002<\/li>\n<li><strong>\u5168\u6587\u7d22\u5f15<\/strong>\uff1a\u7528\u65bc\u6587\u672c\u641c\u7d22\uff0c\u80fd\u5920\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b4%a2%e5%bc%95%e5%88%86%e6%9e%90%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7-nCgXlrnQsR\">\u7d22\u5f15\u5206\u6790\u7684\u91cd\u8981\u6027<\/h2>\n<p>\u9032\u884c\u7d22\u5f15\u5206\u6790\u53ef\u4ee5\u5e6b\u52a9\u8b58\u5225\u6027\u80fd\u74f6\u9838\uff0c\u78ba\u4fdd\u67e5\u8a62\u7684\u9ad8\u6548\u57f7\u884c\u3002\u4ee5\u4e0b\u662f\u9032\u884c\u7d22\u5f15\u5206\u6790\u7684\u4e00\u4e9b\u95dc\u9375\u6b65\u9a5f\uff1a<\/p>\n<h3 id=\"1-%e6%9f%a5%e8%a9%a2%e6%80%a7%e8%83%bd%e7%9b%a3%e6%8e%a7-nCgXlrnQsR\">1. \u67e5\u8a62\u6027\u80fd\u76e3\u63a7<\/h3>\n<p>\u4f7f\u7528\u6578\u64da\u5eab\u7684\u6027\u80fd\u76e3\u63a7\u5de5\u5177\uff08\u5982 MySQL \u7684 EXPLAIN \u8a9e\u53e5\uff09\u4f86\u5206\u6790\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u9019\u53ef\u4ee5\u5e6b\u52a9\u8b58\u5225\u54ea\u4e9b\u67e5\u8a62\u672a\u80fd\u6709\u6548\u5229\u7528\u7d22\u5f15\u3002<\/p>\n<pre><code>EXPLAIN SELECT * FROM users WHERE age &gt; 30;<\/code><\/pre>\n<h3 id=\"2-%e7%a2%ba%e5%ae%9a%e7%b4%a2%e5%bc%95%e7%9a%84%e4%bd%bf%e7%94%a8%e6%83%85%e6%b3%81-nCgXlrnQsR\">2. \u78ba\u5b9a\u7d22\u5f15\u7684\u4f7f\u7528\u60c5\u6cc1<\/h3>\n<p>\u901a\u904e\u67e5\u8a62\u65e5\u8a8c\u6216\u6027\u80fd\u5206\u6790\u5de5\u5177\uff0c\u6aa2\u67e5\u54ea\u4e9b\u7d22\u5f15\u88ab\u983b\u7e41\u4f7f\u7528\uff0c\u54ea\u4e9b\u5247\u5f88\u5c11\u4f7f\u7528\u3002\u9019\u6709\u52a9\u65bc\u6c7a\u5b9a\u662f\u5426\u9700\u8981\u522a\u9664\u4e0d\u5fc5\u8981\u7684\u7d22\u5f15\u3002<\/p>\n<h3 id=\"3-%e8%a9%95%e4%bc%b0%e7%b4%a2%e5%bc%95%e7%9a%84%e9%81%b8%e6%93%87%e6%80%a7-nCgXlrnQsR\">3. \u8a55\u4f30\u7d22\u5f15\u7684\u9078\u64c7\u6027<\/h3>\n<p>\u7d22\u5f15\u7684\u9078\u64c7\u6027\u662f\u6307\u7d22\u5f15\u4e2d\u552f\u4e00\u503c\u7684\u6bd4\u4f8b\u3002\u9ad8\u9078\u64c7\u6027\u7684\u7d22\u5f15\u80fd\u5920\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u53ef\u4ee5\u901a\u904e\u4ee5\u4e0b\u516c\u5f0f\u8a08\u7b97\u9078\u64c7\u6027\uff1a<\/p>\n<pre><code>\u9078\u64c7\u6027 = \u552f\u4e00\u503c\u6578\u91cf \/ \u7e3d\u884c\u6578<\/code><\/pre>\n<h2 id=\"%e7%b4%a2%e5%bc%95%e5%84%aa%e5%8c%96%e7%ad%96%e7%95%a5-nCgXlrnQsR\">\u7d22\u5f15\u512a\u5316\u7b56\u7565<\/h2>\n<p>\u5728\u9032\u884c\u7d22\u5f15\u512a\u5316\u6642\uff0c\u53ef\u4ee5\u8003\u616e\u4ee5\u4e0b\u5e7e\u7a2e\u7b56\u7565\uff1a<\/p>\n<h3 id=\"1-%e5%90%88%e4%bd%b5%e7%b4%a2%e5%bc%95-nCgXlrnQsR\">1. \u5408\u4f75\u7d22\u5f15<\/h3>\n<p>\u5982\u679c\u591a\u500b\u67e5\u8a62\u7d93\u5e38\u4f7f\u7528\u76f8\u540c\u7684\u5217\uff0c\u53ef\u4ee5\u8003\u616e\u5275\u5efa\u8907\u5408\u7d22\u5f15\u3002\u4f8b\u5982\uff0c\u5c0d\u65bc\u7d93\u5e38\u67e5\u8a62\u7684\u689d\u4ef6\uff1a<\/p>\n<pre><code>SELECT * FROM orders WHERE user_id = ? AND status = ?;<\/code><\/pre>\n<p>\u53ef\u4ee5\u5275\u5efa\u4e00\u500b\u5305\u542b user_id \u548c status \u7684\u8907\u5408\u7d22\u5f15\u3002<\/p>\n<h3 id=\"2-%e5%88%aa%e9%99%a4%e5%86%97%e9%a4%98%e7%b4%a2%e5%bc%95-nCgXlrnQsR\">2. \u522a\u9664\u5197\u9918\u7d22\u5f15<\/h3>\n<p>\u5b9a\u671f\u6aa2\u67e5\u4e26\u522a\u9664\u4e0d\u518d\u4f7f\u7528\u7684\u7d22\u5f15\uff0c\u9019\u6a23\u53ef\u4ee5\u6e1b\u5c11\u6578\u64da\u5eab\u7684\u7dad\u8b77\u6210\u672c\uff0c\u4e26\u63d0\u9ad8\u5beb\u5165\u6027\u80fd\u3002<\/p>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8%e9%81%a9%e7%95%b6%e7%9a%84%e7%b4%a2%e5%bc%95%e9%a1%9e%e5%9e%8b-nCgXlrnQsR\">3. \u4f7f\u7528\u9069\u7576\u7684\u7d22\u5f15\u985e\u578b<\/h3>\n<p>\u6839\u64da\u67e5\u8a62\u7684\u7279\u6027\u9078\u64c7\u5408\u9069\u7684\u7d22\u5f15\u985e\u578b\u3002\u4f8b\u5982\uff0c\u5c0d\u65bc\u9700\u8981\u9032\u884c\u7bc4\u570d\u67e5\u8a62\u7684\u60c5\u6cc1\uff0cB\u6a39\u7d22\u5f15\u662f\u6700\u4f73\u9078\u64c7\uff1b\u800c\u5c0d\u65bc\u7cbe\u78ba\u67e5\u8a62\uff0c\u54c8\u5e0c\u7d22\u5f15\u53ef\u80fd\u66f4\u5408\u9069\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-nCgXlrnQsR\">\u7d50\u8ad6<\/h2>\n<p>\u9032\u884c\u7d22\u5f15\u5206\u6790\u548c\u512a\u5316\u662f\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\u7684\u91cd\u8981\u6b65\u9a5f\u3002\u901a\u904e\u6709\u6548\u7684\u7d22\u5f15\u7ba1\u7406\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\uff0c\u6e1b\u5c11\u7cfb\u7d71\u8cc7\u6e90\u7684\u6d88\u8017\u3002\u5c0d\u65bc\u4f7f\u7528 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u7684\u7528\u6236\u4f86\u8aaa\uff0c\u826f\u597d\u7684\u7d22\u5f15\u7b56\u7565\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u61c9\u7528\u7a0b\u5e8f\u7684\u6574\u9ad4\u6027\u80fd\uff0c\u78ba\u4fdd\u7528\u6236\u9ad4\u9a57\u7684\u6d41\u66a2\u6027\u3002\u5b9a\u671f\u9032\u884c\u7d22\u5f15\u5206\u6790\u548c\u512a\u5316\uff0c\u5c07\u4f7f\u6578\u64da\u5eab\u7cfb\u7d71\u4fdd\u6301\u9ad8\u6548\u904b\u884c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u9032\u884c\u7d22\u5f15\u5206\u6790\u548c\u512a\u5316\u7684\u904e\u7a0b\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\uff0c\u78ba\u4fdd\u67e5\u8a62\u6548\u7387\u548c\u7cfb\u7d71\u7a69\u5b9a\u6027\u3002<\/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-61395","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61395","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=61395"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61395\/revisions"}],"predecessor-version":[{"id":61396,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61395\/revisions\/61396"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=61395"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=61395"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=61395"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}