{"id":187898,"date":"2024-11-11T18:06:18","date_gmt":"2024-11-11T10:06:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/187898\/"},"modified":"2024-11-11T18:06:19","modified_gmt":"2024-11-11T10:06:19","slug":"%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e8%a7%a3%e6%9e%90%ef%bc%9a%e8%bc%95%e9%ac%86%e6%8f%90%e5%8f%96%e9%97%9c%e9%8d%b5%e6%95%b8%e6%93%9a-%e5%a6%82%e4%bd%95%e6%8f%90%e5%8f%96%e6%95%b8%e6%93%9a","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/187898\/","title":{"rendered":"\u6578\u64da\u5eab\u5b57\u6bb5\u89e3\u6790\uff1a\u8f15\u9b06\u63d0\u53d6\u95dc\u9375\u6578\u64da (\u5982\u4f55\u63d0\u53d6\u6578\u64da\u5eab\u4e2d\u7684\u5b57\u6bb5\u5167\u7684\u6578\u64da)"},"content":{"rendered":"<h1 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e8%a7%a3%e6%9e%90%ef%bc%9a%e8%bc%95%e9%ac%86%e6%8f%90%e5%8f%96%e9%97%9c%e9%8d%b5%e6%95%b8%e6%93%9a-jWFSBZzSUm\">\u6578\u64da\u5eab\u5b57\u6bb5\u89e3\u6790\uff1a\u8f15\u9b06\u63d0\u53d6\u95dc\u9375\u6578\u64da<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u6210\u70ba\u4e86\u4f01\u696d\u548c\u958b\u767c\u8005\u4e0d\u53ef\u6216\u7f3a\u7684\u5de5\u5177\u3002\u7121\u8ad6\u662f\u7528\u65bc\u5b58\u5132\u7528\u6236\u4fe1\u606f\u3001\u4ea4\u6613\u8a18\u9304\u9084\u662f\u7522\u54c1\u6578\u64da\uff0c\u6578\u64da\u5eab\u7684\u6709\u6548\u7ba1\u7406\u548c\u6578\u64da\u63d0\u53d6\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u8f15\u9b06\u63d0\u53d6\u6578\u64da\u5eab\u4e2d\u7684\u5b57\u6bb5\u5167\u7684\u6578\u64da\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%ef%bc%9f-jWFSBZzSUm\">\u4ec0\u9ebc\u662f\u6578\u64da\u5eab\u5b57\u6bb5\uff1f<\/h2>\n<p>\u6578\u64da\u5eab\u5b57\u6bb5\u662f\u6578\u64da\u5eab\u8868\u4e2d\u7684\u4e00\u500b\u5217\uff0c\u4ee3\u8868\u7279\u5b9a\u985e\u578b\u7684\u4fe1\u606f\u3002\u6bcf\u500b\u5b57\u6bb5\u90fd\u6709\u4e00\u500b\u540d\u7a31\u548c\u6578\u64da\u985e\u578b\uff0c\u4f8b\u5982\u6574\u6578\u3001\u5b57\u7b26\u4e32\u6216\u65e5\u671f\u3002\u5b57\u6bb5\u7684\u8a2d\u8a08\u5c0d\u65bc\u6578\u64da\u7684\u7d44\u7e54\u548c\u6aa2\u7d22\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<h2 id=\"%e7%82%ba%e4%bb%80%e9%ba%bc%e9%9c%80%e8%a6%81%e6%8f%90%e5%8f%96%e6%95%b8%e6%93%9a%ef%bc%9f-jWFSBZzSUm\">\u70ba\u4ec0\u9ebc\u9700\u8981\u63d0\u53d6\u6578\u64da\uff1f<\/h2>\n<p>\u63d0\u53d6\u6578\u64da\u7684\u539f\u56e0\u591a\u7a2e\u591a\u6a23\uff0c\u5305\u62ec\uff1a<\/p>\n<ul>\n<li>\u751f\u6210\u5831\u544a\u548c\u5206\u6790<\/li>\n<li>\u652f\u6301\u696d\u52d9\u6c7a\u7b56<\/li>\n<li>\u6578\u64da\u9077\u79fb\u548c\u6574\u5408<\/li>\n<li>\u5be6\u6642\u6578\u64da\u66f4\u65b0<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e6%8f%90%e5%8f%96%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e7%9a%84%e5%ad%97%e6%ae%b5%e6%95%b8%e6%93%9a-jWFSBZzSUm\">\u5982\u4f55\u63d0\u53d6\u6578\u64da\u5eab\u4e2d\u7684\u5b57\u6bb5\u6578\u64da<\/h2>\n<p>\u63d0\u53d6\u6578\u64da\u7684\u904e\u7a0b\u901a\u5e38\u6d89\u53ca\u4f7f\u7528\u67e5\u8a62\u8a9e\u8a00\uff0c\u5982SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u57fa\u672c\u7684SQL\u67e5\u8a62\u793a\u4f8b\uff0c\u5e6b\u52a9\u60a8\u7406\u89e3\u5982\u4f55\u5f9e\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u5b57\u6bb5\u6578\u64da\u3002<\/p>\n<h3 id=\"%e5%9f%ba%e6%9c%ac%e7%9a%84select%e6%9f%a5%e8%a9%a2-jWFSBZzSUm\">\u57fa\u672c\u7684SELECT\u67e5\u8a62<\/h3>\n<pre><code>SELECT column_name FROM table_name;<\/code><\/pre>\n<p>\u9019\u662f\u4e00\u500b\u6700\u57fa\u672c\u7684\u67e5\u8a62\uff0c\u5f9e\u6307\u5b9a\u7684\u8868\u4e2d\u9078\u64c7\u7279\u5b9a\u7684\u5b57\u6bb5\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba\u201cusers\u201d\u7684\u8868\uff0c\u4e26\u5e0c\u671b\u63d0\u53d6\u201cusername\u201d\u5b57\u6bb5\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT username FROM users;<\/code><\/pre>\n<h3 id=\"%e4%bd%bf%e7%94%a8where%e5%ad%90%e5%8f%a5%e9%80%b2%e8%a1%8c%e6%a2%9d%e4%bb%b6%e7%af%a9%e9%81%b8-jWFSBZzSUm\">\u4f7f\u7528WHERE\u5b50\u53e5\u9032\u884c\u689d\u4ef6\u7be9\u9078<\/h3>\n<p>\u6709\u6642\u5019\uff0c\u6211\u5011\u9700\u8981\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u4f86\u7be9\u9078\u6578\u64da\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528WHERE\u5b50\u53e5\u3002\u4f8b\u5982\uff0c\u63d0\u53d6\u6240\u6709\u5e74\u9f61\u5927\u65bc30\u7684\u7528\u6236\uff1a<\/p>\n<pre><code>SELECT username FROM users WHERE age &gt; 30;<\/code><\/pre>\n<h3 id=\"%e6%8f%90%e5%8f%96%e5%a4%9a%e5%80%8b%e5%ad%97%e6%ae%b5-jWFSBZzSUm\">\u63d0\u53d6\u591a\u500b\u5b57\u6bb5<\/h3>\n<p>\u5982\u679c\u9700\u8981\u63d0\u53d6\u591a\u500b\u5b57\u6bb5\uff0c\u53ef\u4ee5\u5728SELECT\u8a9e\u53e5\u4e2d\u5217\u51fa\u9019\u4e9b\u5b57\u6bb5\uff1a<\/p>\n<pre><code>SELECT username, email FROM users;<\/code><\/pre>\n<h3 id=\"%e4%bd%bf%e7%94%a8%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8-jWFSBZzSUm\">\u4f7f\u7528\u805a\u5408\u51fd\u6578<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u60a8\u53ef\u80fd\u9700\u8981\u5c0d\u6578\u64da\u9032\u884c\u805a\u5408\uff0c\u4f8b\u5982\u8a08\u7b97\u7e3d\u6578\u6216\u5e73\u5747\u503c\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528COUNT\u51fd\u6578\u8a08\u7b97\u7528\u6236\u6578\u91cf\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT COUNT(*) FROM users;<\/code><\/pre>\n<h2 id=\"%e9%80%b2%e9%9a%8e%e6%95%b8%e6%93%9a%e6%8f%90%e5%8f%96%e6%8a%80%e5%b7%a7-jWFSBZzSUm\">\u9032\u968e\u6578\u64da\u63d0\u53d6\u6280\u5de7<\/h2>\n<p>\u9664\u4e86\u57fa\u672c\u7684\u67e5\u8a62\uff0c\u9084\u6709\u4e00\u4e9b\u9032\u968e\u6280\u5de7\u53ef\u4ee5\u5e6b\u52a9\u60a8\u66f4\u6709\u6548\u5730\u63d0\u53d6\u6578\u64da\uff1a<\/p>\n<ul>\n<li><strong>JOIN\u64cd\u4f5c\uff1a<\/strong>\u7576\u6578\u64da\u5206\u6563\u5728\u591a\u500b\u8868\u4e2d\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528JOIN\u64cd\u4f5c\u4f86\u5408\u4f75\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/li>\n<pre><code>SELECT users.username, orders.order_id \nFROM users \nJOIN orders ON users.id = orders.user_id;<\/code><\/pre>\n<li><strong>\u5b50\u67e5\u8a62\uff1a<\/strong>\u53ef\u4ee5\u5728\u67e5\u8a62\u4e2d\u5d4c\u5957\u5176\u4ed6\u67e5\u8a62\uff0c\u4ee5\u7372\u53d6\u66f4\u8907\u96dc\u7684\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/li>\n<pre><code>SELECT username \nFROM users \nWHERE id IN (SELECT user_id FROM orders WHERE total &gt; 100);<\/code><\/pre>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-jWFSBZzSUm\">\u7e3d\u7d50<\/h2>\n<p>\u63d0\u53d6\u6578\u64da\u5eab\u4e2d\u7684\u5b57\u6bb5\u6578\u64da\u662f\u4e00\u9805\u57fa\u672c\u4f46\u91cd\u8981\u7684\u6280\u80fd\uff0c\u7121\u8ad6\u662f\u5728\u6578\u64da\u5206\u6790\u3001\u5831\u544a\u751f\u6210\u9084\u662f\u696d\u52d9\u6c7a\u7b56\u4e2d\u3002\u901a\u904e\u638c\u63e1\u57fa\u672c\u7684SQL\u67e5\u8a62\u548c\u9032\u968e\u6280\u5de7\uff0c\u60a8\u53ef\u4ee5\u8f15\u9b06\u5730\u5f9e\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u6240\u9700\u7684\u4fe1\u606f\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u548c\u63d0\u53d6\u7684\u4f01\u696d\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u81f3\u95dc\u91cd\u8981\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u985e\u578b\u7684 <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a>\uff0c\u90fd\u80fd\u70ba\u60a8\u7684\u6578\u64da\u5eab\u64cd\u4f5c\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u8f15\u9b06\u63d0\u53d6\u6578\u64da\u5eab\u5b57\u6bb5\u4e2d\u7684\u95dc\u9375\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u6548\u7387\uff0c\u638c\u63e1\u6578\u64da\u5eab\u5b57\u6bb5\u89e3\u6790\u6280\u5de7\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-187898","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/187898","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=187898"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/187898\/revisions"}],"predecessor-version":[{"id":187899,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/187898\/revisions\/187899"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=187898"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=187898"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=187898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}