{"id":143767,"date":"2024-11-01T01:04:20","date_gmt":"2024-10-31T17:04:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/143767\/"},"modified":"2024-11-01T01:04:21","modified_gmt":"2024-10-31T17:04:21","slug":"sql-%e6%9f%a5%e8%a9%a2%e6%9c%80%e5%a4%a7%e5%80%bc%e6%9c%80%e5%b0%8f%e5%80%bc%e5%95%8f%e9%a1%8c","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/143767\/","title":{"rendered":"SQL \u67e5\u8a62\u6700\u5927\u503c\u6700\u5c0f\u503c\u554f\u984c"},"content":{"rendered":"<h1 id=\"sql-%e6%9f%a5%e8%a9%a2%e6%9c%80%e5%a4%a7%e5%80%bc%e6%9c%80%e5%b0%8f%e5%80%bc%e5%95%8f%e9%a1%8c-KwNmdpHRoD\">SQL \u67e5\u8a62\u6700\u5927\u503c\u6700\u5c0f\u503c\u554f\u984c<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u4e00\u7a2e\u7528\u65bc\u67e5\u8a62\u548c\u64cd\u4f5c\u8cc7\u6599\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u7576\u6211\u5011\u9700\u8981\u5f9e\u8cc7\u6599\u8868\u4e2d\u7372\u53d6\u7279\u5b9a\u6578\u64da\u6642\uff0c\u67e5\u8a62\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u7684\u529f\u80fd\u986f\u5f97\u5c24\u70ba\u91cd\u8981\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8a62\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\uff0c\u4e26\u63d0\u4f9b\u76f8\u95dc\u7684\u7bc4\u4f8b\u548c\u4ee3\u78bc\u3002<\/p>\n<h2 id=\"%e6%9c%80%e5%a4%a7%e5%80%bc%e5%92%8c%e6%9c%80%e5%b0%8f%e5%80%bc%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-KwNmdpHRoD\">\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u67e5\u8a62\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u901a\u5e38\u4f7f\u7528 <code>MAX()<\/code> \u548c <code>MIN()<\/code> \u51fd\u6578\u3002\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u5f9e\u4e00\u500b\u6578\u64da\u96c6\u6216\u8cc7\u6599\u8868\u4e2d\u63d0\u53d6\u51fa\u6700\u5927\u7684\u6216\u6700\u5c0f\u7684\u6578\u503c\u3002\u9019\u5728\u6578\u64da\u5206\u6790\u3001\u5831\u544a\u751f\u6210\u548c\u6c7a\u7b56\u652f\u6301\u4e2d\u975e\u5e38\u6709\u7528\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-max-%e5%92%8c-min-%e5%87%bd%e6%95%b8-KwNmdpHRoD\">\u4f7f\u7528 MAX() \u548c MIN() \u51fd\u6578<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4f7f\u7528 <code>MAX()<\/code> \u548c <code>MIN()<\/code> \u51fd\u6578\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>SELECT MAX(column_name) FROM table_name;<\/code><\/pre>\n<pre><code>SELECT MIN(column_name) FROM table_name;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>column_name<\/code> \u662f\u4f60\u60f3\u8981\u67e5\u8a62\u7684\u5217\u540d\uff0c\u800c <code>table_name<\/code> \u662f\u8cc7\u6599\u8868\u7684\u540d\u7a31\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e6%9f%a5%e8%a9%a2%e6%9c%80%e5%a4%a7%e5%80%bc-KwNmdpHRoD\">\u7bc4\u4f8b\uff1a\u67e5\u8a62\u6700\u5927\u503c<\/h3>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>employees<\/code> \u7684\u8cc7\u6599\u8868\uff0c\u8a72\u8868\u5305\u542b\u54e1\u5de5\u7684\u85aa\u8cc7\u8cc7\u8a0a\u3002\u82e5\u8981\u67e5\u8a62\u6700\u9ad8\u85aa\u8cc7\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT MAX(salary) AS highest_salary FROM employees;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de <code>employees<\/code> \u8868\u4e2d\u6700\u9ad8\u7684\u85aa\u8cc7\u503c\uff0c\u4e26\u5c07\u5176\u547d\u540d\u70ba <code>highest_salary<\/code>\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e6%9f%a5%e8%a9%a2%e6%9c%80%e5%b0%8f%e5%80%bc-KwNmdpHRoD\">\u7bc4\u4f8b\uff1a\u67e5\u8a62\u6700\u5c0f\u503c<\/h3>\n<p>\u540c\u6a23\u5730\uff0c\u82e5\u8981\u67e5\u8a62\u6700\u4f4e\u85aa\u8cc7\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT MIN(salary) AS lowest_salary FROM employees;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de <code>employees<\/code> \u8868\u4e2d\u6700\u4f4e\u7684\u85aa\u8cc7\u503c\uff0c\u4e26\u5c07\u5176\u547d\u540d\u70ba <code>lowest_salary<\/code>\u3002<\/p>\n<h2 id=\"%e7%b5%90%e5%90%88%e5%85%b6%e4%bb%96%e6%9f%a5%e8%a9%a2-KwNmdpHRoD\">\u7d50\u5408\u5176\u4ed6\u67e5\u8a62<\/h2>\n<p>\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u6211\u5011\u7d93\u5e38\u9700\u8981\u5c07\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u7684\u67e5\u8a62\u8207\u5176\u4ed6\u67e5\u8a62\u7d50\u5408\u4f7f\u7528\u3002\u4f8b\u5982\uff0c\u82e5\u8981\u67e5\u8a62\u6bcf\u500b\u90e8\u9580\u7684\u6700\u9ad8\u85aa\u8cc7\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT department, MAX(salary) AS highest_salary \nFROM employees \nGROUP BY department;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u90e8\u9580\u7684\u6700\u9ad8\u85aa\u8cc7\uff0c\u4e26\u6839\u64da\u90e8\u9580\u9032\u884c\u5206\u7d44\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-KwNmdpHRoD\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u4f7f\u7528 <code>MAX()<\/code> \u548c <code>MIN()<\/code> \u51fd\u6578\u6642\uff0c\u6709\u5e7e\u9ede\u9700\u8981\u6ce8\u610f\uff1a<\/p>\n<ul>\n<li>\u9019\u4e9b\u51fd\u6578\u53ea\u80fd\u7528\u65bc\u6578\u503c\u578b\u6216\u65e5\u671f\u578b\u7684\u5217\u3002<\/li>\n<li>\u5982\u679c\u8cc7\u6599\u8868\u4e2d\u6c92\u6709\u6578\u64da\uff0c\u5247\u8fd4\u56de\u7684\u7d50\u679c\u5c07\u70ba <code>NULL<\/code>\u3002<\/li>\n<li>\u5728\u4f7f\u7528 <code>GROUP BY<\/code> \u6642\uff0c\u5fc5\u9808\u78ba\u4fdd\u6240\u6709\u975e\u805a\u5408\u5217\u90fd\u5305\u542b\u5728 <code>GROUP BY<\/code> \u5b50\u53e5\u4e2d\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-KwNmdpHRoD\">\u7e3d\u7d50<\/h2>\n<p>SQL \u4e2d\u7684\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\u67e5\u8a62\u662f\u6578\u64da\u5206\u6790\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u5de5\u5177\u3002\u901a\u904e\u4f7f\u7528 <code>MAX()<\/code> \u548c <code>MIN()<\/code> \u51fd\u6578\uff0c\u4f7f\u7528\u8005\u53ef\u4ee5\u8f15\u9b06\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\uff0c\u4e26\u9032\u884c\u9032\u4e00\u6b65\u7684\u5206\u6790\u548c\u5831\u544a\u3002\u7121\u8ad6\u662f\u5728\u4f01\u696d\u74b0\u5883\u9084\u662f\u500b\u4eba\u9805\u76ee\u4e2d\uff0c\u638c\u63e1\u9019\u4e9b\u57fa\u672c\u7684 SQL \u67e5\u8a62\u6280\u5de7\u90fd\u5c07\u5927\u5927\u63d0\u9ad8\u5de5\u4f5c\u6548\u7387\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u670d\u52d9\u6709\u8208\u8da3\uff0c\u6216\u60f3\u4e86\u89e3\u66f4\u591a\u95dc\u65bc <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a> \u7684\u8cc7\u8a0a\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u8a73\u7d30\u8cc7\u6599\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 SQL \u67e5\u8a62\u4e2d\u5982\u4f55\u6709\u6548\u7372\u53d6\u6578\u64da\u7684\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u80fd\u529b\uff0c\u512a\u5316\u67e5\u8a62\u6027\u80fd\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-143767","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143767","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=143767"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143767\/revisions"}],"predecessor-version":[{"id":143768,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143767\/revisions\/143768"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=143767"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=143767"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=143767"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}