{"id":76646,"date":"2024-10-16T08:38:15","date_gmt":"2024-10-16T00:38:15","guid":{"rendered":"https:\/\/server.hk\/cnblog\/76646\/"},"modified":"2024-10-16T08:38:16","modified_gmt":"2024-10-16T00:38:16","slug":"mysql%e6%95%b8%e6%93%9a%e5%ba%ab%e5%84%aa%e5%8c%96sql%e8%aa%9e%e5%8f%a5%e7%9a%84%e6%ad%a5%e9%a9%9f4","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/76646\/","title":{"rendered":"MySQL\u6578\u64da\u5eab\u512a\u5316SQL\u8a9e\u53e5\u7684\u6b65\u9a5f4"},"content":{"rendered":"<h1 id=\"mysql%e6%95%b8%e6%93%9a%e5%ba%ab%e5%84%aa%e5%8c%96sql%e8%aa%9e%e5%8f%a5%e7%9a%84%e6%ad%a5%e9%a9%9f4-KmZaGIEUnj\">MySQL\u6578\u64da\u5eab\u512a\u5316SQL\u8a9e\u53e5\u7684\u6b65\u9a5f4<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0cMySQL\u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u3002\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u512a\u5316SQL\u8a9e\u53e5\u8b8a\u5f97\u81f3\u95dc\u91cd\u8981\u3002\u672c\u6587\u5c07\u63a2\u8a0eMySQL\u6578\u64da\u5eab\u512a\u5316SQL\u8a9e\u53e5\u7684\u7b2c\u56db\u6b65\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u6e1b\u5c11\u8cc7\u6e90\u6d88\u8017\u3002<\/p>\n<h2 id=\"%e6%ad%a5%e9%a9%9f4%ef%bc%9a%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95%e4%be%86%e5%8a%a0%e9%80%9f%e6%9f%a5%e8%a9%a2-KmZaGIEUnj\">\u6b65\u9a5f4\uff1a\u4f7f\u7528\u7d22\u5f15\u4f86\u52a0\u901f\u67e5\u8a62<\/h2>\n<p>\u7d22\u5f15\u662f\u6578\u64da\u5eab\u4e2d\u4e00\u7a2e\u91cd\u8981\u7684\u6578\u64da\u7d50\u69cb\uff0c\u80fd\u5920\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u901a\u904e\u70ba\u8868\u4e2d\u7684\u4e00\u500b\u6216\u591a\u500b\u5217\u5275\u5efa\u7d22\u5f15\uff0cMySQL\u53ef\u4ee5\u66f4\u5feb\u5730\u5b9a\u4f4d\u5230\u6240\u9700\u7684\u6578\u64da\uff0c\u800c\u7121\u9700\u6383\u63cf\u6574\u500b\u8868\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528\u7d22\u5f15\u7684\u5e7e\u500b\u95dc\u9375\u9ede\uff1a<\/p>\n<h3 id=\"1-%e7%a2%ba%e5%ae%9a%e9%9c%80%e8%a6%81%e7%b4%a2%e5%bc%95%e7%9a%84%e5%88%97-KmZaGIEUnj\">1. \u78ba\u5b9a\u9700\u8981\u7d22\u5f15\u7684\u5217<\/h3>\n<p>\u5728\u6c7a\u5b9a\u70ba\u54ea\u4e9b\u5217\u5275\u5efa\u7d22\u5f15\u6642\uff0c\u61c9\u8003\u616e\u4ee5\u4e0b\u5e7e\u500b\u56e0\u7d20\uff1a<\/p>\n<ul>\n<li>\u67e5\u8a62\u4e2d\u7d93\u5e38\u4f7f\u7528\u7684\u5217\uff1a\u5982\u679c\u67d0\u5217\u7d93\u5e38\u51fa\u73fe\u5728WHERE\u5b50\u53e5\u4e2d\uff0c\u5247\u61c9\u8003\u616e\u70ba\u5176\u5275\u5efa\u7d22\u5f15\u3002<\/li>\n<li>JOIN\u64cd\u4f5c\u4e2d\u7684\u5217\uff1a\u5728\u591a\u500b\u8868\u4e4b\u9593\u9032\u884cJOIN\u64cd\u4f5c\u6642\uff0c\u53c3\u8207JOIN\u7684\u5217\u61c9\u8a72\u88ab\u7d22\u5f15\u3002<\/li>\n<li>ORDER BY\u548cGROUP BY\u4e2d\u7684\u5217\uff1a\u9019\u4e9b\u64cd\u4f5c\u4e5f\u53ef\u4ee5\u5f9e\u7d22\u5f15\u4e2d\u53d7\u76ca\u3002<\/li>\n<\/ul>\n<h3 id=\"2-%e5%89%b5%e5%bb%ba%e7%b4%a2%e5%bc%95%e7%9a%84%e8%aa%9e%e6%b3%95-KmZaGIEUnj\">2. \u5275\u5efa\u7d22\u5f15\u7684\u8a9e\u6cd5<\/h3>\n<p>\u5728MySQL\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\u5275\u5efa\u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE INDEX index_name ON table_name (column1, column2, ...);<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba\u201cusers\u201d\u7684\u8868\uff0c\u4e26\u4e14\u7d93\u5e38\u6839\u64da\u201cemail\u201d\u5217\u9032\u884c\u67e5\u8a62\uff0c\u6211\u5011\u53ef\u4ee5\u9019\u6a23\u5275\u5efa\u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE INDEX idx_email ON users (email);<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8%e8%a4%87%e5%90%88%e7%b4%a2%e5%bc%95-KmZaGIEUnj\">3. \u4f7f\u7528\u8907\u5408\u7d22\u5f15<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u55ae\u5217\u7d22\u5f15\u53ef\u80fd\u4e0d\u8db3\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u9019\u6642\uff0c\u53ef\u4ee5\u8003\u616e\u4f7f\u7528\u8907\u5408\u7d22\u5f15\uff0c\u5373\u5728\u591a\u500b\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\u3002\u8907\u5408\u7d22\u5f15\u7684\u5275\u5efa\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE INDEX index_name ON table_name (column1, column2);<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u7d93\u5e38\u6839\u64da\u201clast_name\u201d\u548c\u201cfirst_name\u201d\u9032\u884c\u67e5\u8a62\uff0c\u53ef\u4ee5\u9019\u6a23\u5275\u5efa\u8907\u5408\u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE INDEX idx_name ON users (last_name, first_name);<\/code><\/pre>\n<h3 id=\"4-%e5%ae%9a%e6%9c%9f%e6%aa%a2%e6%9f%a5%e5%92%8c%e7%b6%ad%e8%ad%b7%e7%b4%a2%e5%bc%95-KmZaGIEUnj\">4. \u5b9a\u671f\u6aa2\u67e5\u548c\u7dad\u8b77\u7d22\u5f15<\/h3>\n<p>\u96a8\u8457\u6578\u64da\u7684\u8b8a\u5316\uff0c\u7d22\u5f15\u7684\u6709\u6548\u6027\u53ef\u80fd\u6703\u4e0b\u964d\u3002\u56e0\u6b64\uff0c\u5b9a\u671f\u6aa2\u67e5\u548c\u7dad\u8b77\u7d22\u5f15\u662f\u5fc5\u8981\u7684\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\u67e5\u770b\u8868\u7684\u7d22\u5f15\uff1a<\/p>\n<pre><code>SHOW INDEX FROM table_name;<\/code><\/pre>\n<p>\u5982\u679c\u767c\u73fe\u67d0\u4e9b\u7d22\u5f15\u4e0d\u518d\u4f7f\u7528\uff0c\u53ef\u4ee5\u8003\u616e\u522a\u9664\u5b83\u5011\uff0c\u4ee5\u6e1b\u5c11\u6578\u64da\u5eab\u7684\u958b\u92b7\uff1a<\/p>\n<pre><code>DROP INDEX index_name ON table_name;<\/code><\/pre>\n<h2 id=\"%e7%b5%90%e8%ab%96-KmZaGIEUnj\">\u7d50\u8ad6<\/h2>\n<p>\u512a\u5316MySQL\u6578\u64da\u5eab\u7684SQL\u8a9e\u53e5\u662f\u4e00\u500b\u6301\u7e8c\u7684\u904e\u7a0b\uff0c\u5176\u4e2d\u4f7f\u7528\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u95dc\u9375\u6b65\u9a5f\u4e4b\u4e00\u3002\u901a\u904e\u6b63\u78ba\u5730\u9078\u64c7\u548c\u7dad\u8b77\u7d22\u5f15\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u97ff\u61c9\u901f\u5ea6\u548c\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6027\u80fd\u6578\u64da\u5eab\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u904b\u884c\u5728\u7a69\u5b9a\u548c\u9ad8\u6548\u7684\u74b0\u5883\u4e2d\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u638c\u63e1MySQL\u6578\u64da\u5eab\u512a\u5316SQL\u8a9e\u53e5\u7684\u56db\u500b\u6b65\u9a5f\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff0c\u6e1b\u5c11\u8cc7\u6e90\u6d88\u8017\uff0c\u78ba\u4fdd\u7cfb\u7d71\u7a69\u5b9a\u904b\u884c\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-76646","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/76646","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=76646"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/76646\/revisions"}],"predecessor-version":[{"id":76647,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/76646\/revisions\/76647"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=76646"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=76646"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=76646"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}