{"id":152669,"date":"2024-11-02T01:02:23","date_gmt":"2024-11-01T17:02:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/152669\/"},"modified":"2024-11-02T01:02:24","modified_gmt":"2024-11-01T17:02:24","slug":"%e6%9f%a5%e8%a9%a2%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ba%ab%e6%96%b9%e6%b3%95%e7%b0%a1%e6%9e%90%ef%bc%9a%e5%be%9e-sql-%e8%aa%9e%e5%8f%a5%e5%9f%ba%e7%a4%8e%e5%88%b0%e9%ab%98%e6%95%88%e6%9f%a5%e8%a9%a2","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/152669\/","title":{"rendered":"\u67e5\u8a62\u6578\u64da\u5eab\u5eab\u65b9\u6cd5\u7c21\u6790\uff1a\u5f9e SQL \u8a9e\u53e5\u57fa\u790e\u5230\u9ad8\u6548\u67e5\u8a62\u6280\u5de7 (\u600e\u9ebc\u67e5\u8a62\u6578\u64da\u5eab\u5eab)"},"content":{"rendered":"<h1 id=\"%e6%9f%a5%e8%a9%a2%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ba%ab%e6%96%b9%e6%b3%95%e7%b0%a1%e6%9e%90%ef%bc%9a%e5%be%9e-sql-%e8%aa%9e%e5%8f%a5%e5%9f%ba%e7%a4%8e%e5%88%b0%e9%ab%98%e6%95%88%e6%9f%a5%e8%a9%a2-XYgCmauHjj\">\u67e5\u8a62\u6578\u64da\u5eab\u5eab\u65b9\u6cd5\u7c21\u6790\uff1a\u5f9e SQL \u8a9e\u53e5\u57fa\u790e\u5230\u9ad8\u6548\u67e5\u8a62\u6280\u5de7<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u67e5\u8a62\u662f\u4fe1\u606f\u7ba1\u7406\u548c\u5206\u6790\u7684\u6838\u5fc3\u3002\u7121\u8ad6\u662f\u4f01\u696d\u9084\u662f\u500b\u4eba\uff0c\u80fd\u5920\u6709\u6548\u5730\u67e5\u8a62\u6578\u64da\u5eab\u90fd\u662f\u4e00\u9805\u91cd\u8981\u7684\u6280\u80fd\u3002\u672c\u6587\u5c07\u5f9e SQL \u8a9e\u53e5\u7684\u57fa\u790e\u958b\u59cb\uff0c\u9010\u6b65\u6df1\u5165\u5230\u9ad8\u6548\u67e5\u8a62\u7684\u6280\u5de7\uff0c\u5e6b\u52a9\u8b80\u8005\u638c\u63e1\u67e5\u8a62\u6578\u64da\u5eab\u7684\u57fa\u672c\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"%e4%b8%80%e3%80%81sql-%e8%aa%9e%e5%8f%a5%e5%9f%ba%e7%a4%8e-XYgCmauHjj\">\u4e00\u3001SQL \u8a9e\u53e5\u57fa\u790e<\/h2>\n<p>SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u7528\u65bc\u7ba1\u7406\u548c\u64cd\u4f5c\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u6700\u57fa\u672c\u7684 SQL \u8a9e\u53e5\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>SELECT<\/code>\uff1a\u7528\u65bc\u67e5\u8a62\u6578\u64da\u3002<\/li>\n<li><code>INSERT<\/code>\uff1a\u7528\u65bc\u63d2\u5165\u65b0\u6578\u64da\u3002<\/li>\n<li><code>UPDATE<\/code>\uff1a\u7528\u65bc\u66f4\u65b0\u73fe\u6709\u6578\u64da\u3002<\/li>\n<li><code>DELETE<\/code>\uff1a\u7528\u65bc\u522a\u9664\u6578\u64da\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684\u67e5\u8a62\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT * FROM users WHERE age &gt; 18;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u5f9e\u540d\u70ba <code>users<\/code> \u7684\u8868\u4e2d\u9078\u64c7\u6240\u6709\u5e74\u9f61\u5927\u65bc 18 \u7684\u7528\u6236\u3002<\/p>\n<h2 id=\"%e4%ba%8c%e3%80%81%e6%9f%a5%e8%a9%a2%e6%95%b8%e6%93%9a%e7%9a%84%e5%9f%ba%e6%9c%ac%e7%b5%90%e6%a7%8b-XYgCmauHjj\">\u4e8c\u3001\u67e5\u8a62\u6578\u64da\u7684\u57fa\u672c\u7d50\u69cb<\/h2>\n<p>\u4e00\u689d\u5b8c\u6574\u7684 SQL \u67e5\u8a62\u8a9e\u53e5\u901a\u5e38\u7531\u4ee5\u4e0b\u5e7e\u500b\u90e8\u5206\u7d44\u6210\uff1a<\/p>\n<ul>\n<li><strong>SELECT<\/strong>\uff1a\u6307\u5b9a\u8981\u67e5\u8a62\u7684\u5217\u3002<\/li>\n<li><strong>FROM<\/strong>\uff1a\u6307\u5b9a\u8981\u67e5\u8a62\u7684\u8868\u3002<\/li>\n<li><strong>WHERE<\/strong>\uff1a\u6307\u5b9a\u67e5\u8a62\u7684\u689d\u4ef6\u3002<\/li>\n<li><strong>ORDER BY<\/strong>\uff1a\u6307\u5b9a\u7d50\u679c\u7684\u6392\u5e8f\u65b9\u5f0f\u3002<\/li>\n<li><strong>LIMIT<\/strong>\uff1a\u9650\u5236\u8fd4\u56de\u7684\u8a18\u9304\u6578\u91cf\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT name, email FROM users WHERE age &gt; 18 ORDER BY name LIMIT 10;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u8fd4\u56de\u5e74\u9f61\u5927\u65bc 18 \u7684\u7528\u6236\u7684\u59d3\u540d\u548c\u96fb\u5b50\u90f5\u4ef6\uff0c\u4e26\u6309\u59d3\u540d\u6392\u5e8f\uff0c\u6700\u591a\u8fd4\u56de 10 \u689d\u8a18\u9304\u3002<\/p>\n<h2 id=\"%e4%b8%89%e3%80%81%e9%ab%98%e6%95%88%e6%9f%a5%e8%a9%a2%e6%8a%80%e5%b7%a7-XYgCmauHjj\">\u4e09\u3001\u9ad8\u6548\u67e5\u8a62\u6280\u5de7<\/h2>\n<p>\u5728\u9032\u884c\u6578\u64da\u5eab\u67e5\u8a62\u6642\uff0c\u6548\u7387\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u7684\u6280\u5de7\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95-XYgCmauHjj\">1. \u4f7f\u7528\u7d22\u5f15<\/h3>\n<p>\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\u3002\u901a\u904e\u5728\u7d93\u5e38\u67e5\u8a62\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u53ef\u4ee5\u52a0\u5feb\u6578\u64da\u6aa2\u7d22\u7684\u901f\u5ea6\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>CREATE INDEX idx_age ON users(age);<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u5728 <code>users<\/code> \u8868\u7684 <code>age<\/code> \u5217\u4e0a\u5275\u5efa\u7d22\u5f15\u3002<\/p>\n<h3 id=\"2-%e9%81%bf%e5%85%8d%e4%bd%bf%e7%94%a8-select-XYgCmauHjj\">2. \u907f\u514d\u4f7f\u7528 SELECT *<\/h3>\n<p>\u4f7f\u7528 <code>SELECT *<\/code> \u6703\u8fd4\u56de\u8868\u4e2d\u7684\u6240\u6709\u5217\uff0c\u9019\u53ef\u80fd\u6703\u5c0e\u81f4\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u50b3\u8f38\u3002\u61c9\u8a72\u53ea\u9078\u64c7\u9700\u8981\u7684\u5217\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT name, email FROM users;<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8-join-%e9%80%b2%e8%a1%8c%e5%a4%9a%e8%a1%a8%e6%9f%a5%e8%a9%a2-XYgCmauHjj\">3. \u4f7f\u7528 JOIN \u9032\u884c\u591a\u8868\u67e5\u8a62<\/h3>\n<p>\u7576\u9700\u8981\u5f9e\u591a\u500b\u8868\u4e2d\u7372\u53d6\u6578\u64da\u6642\uff0c\u4f7f\u7528 <code>JOIN<\/code> \u53ef\u4ee5\u6709\u6548\u5730\u5408\u4f75\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT users.name, orders.amount \nFROM users \nJOIN orders ON users.id = orders.user_id;<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u8fd4\u56de\u7528\u6236\u7684\u59d3\u540d\u53ca\u5176\u8a02\u55ae\u91d1\u984d\u3002<\/p>\n<h3 id=\"4-%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%a9%a2-XYgCmauHjj\">4. \u4f7f\u7528\u5b50\u67e5\u8a62<\/h3>\n<p>\u5b50\u67e5\u8a62\u53ef\u4ee5\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5d4c\u5957\u53e6\u4e00\u500b\u67e5\u8a62\uff0c\u9019\u6a23\u53ef\u4ee5\u66f4\u9748\u6d3b\u5730\u7372\u53d6\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT name FROM users WHERE id IN (SELECT user_id FROM orders WHERE amount &gt; 100);<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07\u8fd4\u56de\u6240\u6709\u5728\u8a02\u55ae\u4e2d\u91d1\u984d\u5927\u65bc 100 \u7684\u7528\u6236\u59d3\u540d\u3002<\/p>\n<h2 id=\"%e5%9b%9b%e3%80%81%e7%b8%bd%e7%b5%90-XYgCmauHjj\">\u56db\u3001\u7e3d\u7d50<\/h2>\n<p>\u638c\u63e1 SQL \u8a9e\u53e5\u7684\u57fa\u672c\u7d50\u69cb\u548c\u9ad8\u6548\u67e5\u8a62\u6280\u5de7\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528\u7d22\u5f15\u3001\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u6aa2\u7d22\u3001\u5229\u7528 JOIN \u548c\u5b50\u67e5\u8a62\u7b49\u65b9\u6cd5\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u9019\u4e9b\u6280\u5de7\u5c07\u5e6b\u52a9\u7528\u6236\u66f4\u6709\u6548\u5730\u7ba1\u7406\u548c\u5206\u6790\u6578\u64da\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u6578\u64da\u5eab\u67e5\u8a62\u6709\u9032\u4e00\u6b65\u7684\u9700\u6c42\uff0c\u7121\u8ad6\u662f\u5c0b\u627e <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u89e3\u6c7a\u65b9\u6848\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u4e86\u89e3\u66f4\u591a\u4fe1\u606f\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22\u67e5\u8a62\u6578\u64da\u5eab\u7684\u65b9\u6cd5\uff0c\u5f9eSQL\u8a9e\u53e5\u57fa\u790e\u5230\u9ad8\u6548\u67e5\u8a62\u6280\u5de7\uff0c\u52a9\u4f60\u63d0\u5347\u6578\u64da\u6aa2\u7d22\u6548\u7387\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-152669","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/152669","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=152669"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/152669\/revisions"}],"predecessor-version":[{"id":152670,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/152669\/revisions\/152670"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=152669"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=152669"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=152669"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}