{"id":66463,"date":"2024-10-14T17:44:14","date_gmt":"2024-10-14T09:44:14","guid":{"rendered":"https:\/\/server.hk\/cnblog\/66463\/"},"modified":"2024-10-14T17:44:14","modified_gmt":"2024-10-14T09:44:14","slug":"mysql-command-select%ef%bc%88%e6%9f%a5%e8%a9%a2%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/66463\/","title":{"rendered":"MySQL Command: SELECT\uff08\u67e5\u8a62\uff09"},"content":{"rendered":"<h1 id=\"mysql-command-select%ef%bc%88%e6%9f%a5%e8%a9%a2%ef%bc%89-UvUuiKHqVH\">MySQL Command: SELECT\uff08\u67e5\u8a62\uff09<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cMySQL \u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u958b\u6e90\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u3002\u5b83\u7684\u5f37\u5927\u529f\u80fd\u548c\u9748\u6d3b\u6027\u4f7f\u5176\u6210\u70ba\u8a31\u591a\u61c9\u7528\u7a0b\u5e8f\u7684\u9996\u9078\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e MySQL \u4e2d\u7684 SELECT \u547d\u4ee4\uff0c\u9019\u662f\u7528\u65bc\u67e5\u8a62\u6578\u64da\u7684\u57fa\u672c\u547d\u4ee4\u4e4b\u4e00\u3002<\/p>\n<h2 id=\"select-%e5%91%bd%e4%bb%a4%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-UvUuiKHqVH\">SELECT \u547d\u4ee4\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p>SELECT \u547d\u4ee4\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT column1, column2, ...\nFROM table_name\nWHERE condition;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>column1, column2, ...<\/code> \u662f\u60a8\u5e0c\u671b\u67e5\u8a62\u7684\u5217\uff0c<code>table_name<\/code> \u662f\u60a8\u8981\u67e5\u8a62\u7684\u8868\u540d\uff0c\u800c <code>condition<\/code> \u662f\u53ef\u9078\u7684\u689d\u4ef6\uff0c\u7528\u65bc\u904e\u6ffe\u7d50\u679c\u3002<\/p>\n<h2 id=\"%e5%9f%ba%e6%9c%ac%e7%a4%ba%e4%be%8b-UvUuiKHqVH\">\u57fa\u672c\u793a\u4f8b<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>employees<\/code> \u7684\u8868\uff0c\u5305\u542b\u4ee5\u4e0b\u5217\uff1a<code>id<\/code>\u3001<code>name<\/code> \u548c <code>salary<\/code>\u3002\u5982\u679c\u6211\u5011\u60f3\u67e5\u8a62\u6240\u6709\u54e1\u5de5\u7684\u59d3\u540d\u548c\u85aa\u6c34\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\uff1a<\/p>\n<pre><code>SELECT name, salary\nFROM employees;<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de <code>employees<\/code> \u8868\u4e2d\u6240\u6709\u54e1\u5de5\u7684\u59d3\u540d\u548c\u85aa\u6c34\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-where-%e5%ad%90%e5%8f%a5-UvUuiKHqVH\">\u4f7f\u7528 WHERE \u5b50\u53e5<\/h2>\n<p>\u5982\u679c\u6211\u5011\u53ea\u60f3\u67e5\u8a62\u85aa\u6c34\u9ad8\u65bc 50000 \u7684\u54e1\u5de5\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>WHERE<\/code> \u5b50\u53e5\u4f86\u904e\u6ffe\u7d50\u679c\uff1a<\/p>\n<pre><code>SELECT name, salary\nFROM employees\nWHERE salary &gt; 50000;<\/code><\/pre>\n<p>\u9019\u6a23\uff0c\u67e5\u8a62\u7d50\u679c\u5c07\u50c5\u986f\u793a\u85aa\u6c34\u9ad8\u65bc 50000 \u7684\u54e1\u5de5\u3002<\/p>\n<h2 id=\"%e6%8e%92%e5%ba%8f%e7%b5%90%e6%9e%9c-UvUuiKHqVH\">\u6392\u5e8f\u7d50\u679c<\/h2>\n<p>\u4f7f\u7528 <code>ORDER BY<\/code> \u5b50\u53e5\u53ef\u4ee5\u5c0d\u67e5\u8a62\u7d50\u679c\u9032\u884c\u6392\u5e8f\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u60f3\u6309\u85aa\u6c34\u5f9e\u9ad8\u5230\u4f4e\u6392\u5e8f\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT name, salary\nFROM employees\nWHERE salary &gt; 50000\nORDER BY salary DESC;<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de\u85aa\u6c34\u9ad8\u65bc 50000 \u7684\u54e1\u5de5\uff0c\u4e26\u6309\u85aa\u6c34\u5f9e\u9ad8\u5230\u4f4e\u6392\u5e8f\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-distinct-%e9%97%9c%e9%8d%b5%e5%ad%97-UvUuiKHqVH\">\u4f7f\u7528 DISTINCT \u95dc\u9375\u5b57<\/h2>\n<p>\u5982\u679c\u6211\u5011\u60f3\u67e5\u8a62\u4e0d\u91cd\u8907\u7684\u85aa\u6c34\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>DISTINCT<\/code> \u95dc\u9375\u5b57\uff1a<\/p>\n<pre><code>SELECT DISTINCT salary\nFROM employees;<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de <code>employees<\/code> \u8868\u4e2d\u6240\u6709\u4e0d\u91cd\u8907\u7684\u85aa\u6c34\u503c\u3002<\/p>\n<h2 id=\"%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8-UvUuiKHqVH\">\u805a\u5408\u51fd\u6578<\/h2>\n<p>MySQL \u9084\u652f\u6301\u591a\u7a2e\u805a\u5408\u51fd\u6578\uff0c\u4f8b\u5982 <code>COUNT<\/code>\u3001<code>SUM<\/code>\u3001<code>AVG<\/code>\u3001<code>MAX<\/code> \u548c <code>MIN<\/code>\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u60f3\u8a08\u7b97\u54e1\u5de5\u7684\u7e3d\u6578\uff0c\u53ef\u4ee5\u4f7f\u7528\uff1a<\/p>\n<pre><code>SELECT COUNT(*)\nFROM employees;<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56de <code>employees<\/code> \u8868\u4e2d\u7684\u7e3d\u54e1\u5de5\u6578\u3002<\/p>\n<h2 id=\"%e5%b0%8f%e7%b5%90-UvUuiKHqVH\">\u5c0f\u7d50<\/h2>\n<p>MySQL \u7684 SELECT \u547d\u4ee4\u662f\u6578\u64da\u67e5\u8a62\u7684\u57fa\u790e\uff0c\u901a\u904e\u9748\u6d3b\u7684\u8a9e\u6cd5\u548c\u591a\u7a2e\u9078\u9805\uff0c\u4f7f\u7528\u8005\u53ef\u4ee5\u8f15\u9b06\u5730\u5f9e\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u6240\u9700\u7684\u4fe1\u606f\u3002\u7121\u8ad6\u662f\u57fa\u672c\u67e5\u8a62\u3001\u689d\u4ef6\u904e\u6ffe\u3001\u6392\u5e8f\u9084\u662f\u4f7f\u7528\u805a\u5408\u51fd\u6578\uff0cSELECT \u547d\u4ee4\u90fd\u80fd\u6eff\u8db3\u5404\u7a2e\u9700\u6c42\u3002<\/p>\n<p>\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\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\u904b\u884c MySQL \u6578\u64da\u5eab\u9084\u662f\u5176\u4ed6\u61c9\u7528\uff0c<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u63d0\u4f9b\u7684\u7a69\u5b9a\u6027\u548c\u6027\u80fd\u90fd\u80fd\u70ba\u60a8\u7684\u696d\u52d9\u63d0\u4f9b\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Learn how to use the MySQL SELECT command to query and retrieve data from databases efficiently. Master data selection with practical examples.<\/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-66463","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66463","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=66463"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66463\/revisions"}],"predecessor-version":[{"id":66464,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/66463\/revisions\/66464"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=66463"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=66463"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=66463"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}