{"id":172563,"date":"2024-11-07T14:10:29","date_gmt":"2024-11-07T06:10:29","guid":{"rendered":"https:\/\/server.hk\/cnblog\/172563\/"},"modified":"2024-11-07T14:10:30","modified_gmt":"2024-11-07T06:10:30","slug":"%e5%a6%82%e4%bd%95%e8%a1%a8%e9%81%94%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e6%9b%b4%e5%a4%a7%e5%80%bc-%e6%80%8e%e9%ba%bc%e8%a1%a8%e7%a4%ba%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e6%9b%b4%e5%a4%a7%e5%80%bc","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/172563\/","title":{"rendered":"\u5982\u4f55\u8868\u9054\u6578\u64da\u5eab\u7684\u66f4\u5927\u503c (\u600e\u9ebc\u8868\u793a\u6578\u64da\u5eab\u7684\u66f4\u5927\u503c)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e8%a1%a8%e9%81%94%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e6%9b%b4%e5%a4%a7%e5%80%bc-uNEuepoMYY\">\u5982\u4f55\u8868\u9054\u6578\u64da\u5eab\u7684\u66f4\u5927\u503c<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u8868\u9054\u6578\u64da\u5eab\u7684\u66f4\u5927\u503c\u662f\u4e00\u500b\u91cd\u8981\u7684\u8ab2\u984c\u3002\u7121\u8ad6\u662f\u9032\u884c\u6578\u64da\u5206\u6790\u3001\u5831\u544a\u751f\u6210\uff0c\u9084\u662f\u6578\u64da\u6316\u6398\uff0c\u4e86\u89e3\u5982\u4f55\u6709\u6548\u5730\u8868\u793a\u548c\u67e5\u8a62\u6578\u64da\u5eab\u4e2d\u7684\u6700\u5927\u503c\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u5e38\u898b\u7684\u65b9\u6cd5\u4f86\u8868\u9054\u6578\u64da\u5eab\u7684\u66f4\u5927\u503c\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8sql%e6%9f%a5%e8%a9%a2%e7%8d%b2%e5%8f%96%e6%9c%80%e5%a4%a7%e5%80%bc-uNEuepoMYY\">1. \u4f7f\u7528SQL\u67e5\u8a62\u7372\u53d6\u6700\u5927\u503c<\/h2>\n<p>\u5728\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u4e2d\uff0c\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u662f\u4f7f\u7528SQL\u67e5\u8a62\u4f86\u7372\u53d6\u67d0\u4e00\u5217\u7684\u6700\u5927\u503c\u3002SQL\u8a9e\u8a00\u63d0\u4f9b\u4e86<strong>MAX()<\/strong>\u51fd\u6578\uff0c\u9019\u662f\u4e00\u500b\u805a\u5408\u51fd\u6578\uff0c\u53ef\u4ee5\u7528\u4f86\u8a08\u7b97\u6307\u5b9a\u5217\u7684\u6700\u5927\u503c\u3002<\/p>\n<pre><code>SELECT MAX(column_name) AS max_value\nFROM table_name;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba<strong>employees<\/strong>\u7684\u8868\u683c\uff0c\u5176\u4e2d\u5305\u542b\u54e1\u5de5\u7684\u85aa\u8cc7\u4fe1\u606f\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\u4f86\u7372\u53d6\u6700\u9ad8\u85aa\u8cc7\uff1a<\/p>\n<pre><code>SELECT MAX(salary) AS max_salary\nFROM employees;<\/code><\/pre>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8group-by%e4%be%86%e7%8d%b2%e5%8f%96%e5%88%86%e7%b5%84%e7%9a%84%e6%9c%80%e5%a4%a7%e5%80%bc-uNEuepoMYY\">2. \u4f7f\u7528GROUP BY\u4f86\u7372\u53d6\u5206\u7d44\u7684\u6700\u5927\u503c<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u6211\u5011\u53ef\u80fd\u9700\u8981\u6839\u64da\u67d0\u500b\u5b57\u6bb5\u9032\u884c\u5206\u7d44\uff0c\u7136\u5f8c\u7372\u53d6\u6bcf\u500b\u7d44\u7684\u6700\u5927\u503c\u3002\u9019\u6642\u53ef\u4ee5\u7d50\u5408\u4f7f\u7528<strong>GROUP BY<\/strong>\u548c<strong>MAX()<\/strong>\u51fd\u6578\u3002<\/p>\n<pre><code>SELECT department, MAX(salary) AS max_salary\nFROM employees\nGROUP BY department;<\/code><\/pre>\n<p>\u4e0a\u8ff0\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u90e8\u9580\u7684\u6700\u9ad8\u85aa\u8cc7\uff0c\u9019\u5c0d\u65bc\u5206\u6790\u4e0d\u540c\u90e8\u9580\u7684\u85aa\u8cc7\u7d50\u69cb\u975e\u5e38\u6709\u7528\u3002<\/p>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%a9%a2%e7%8d%b2%e5%8f%96%e6%9c%80%e5%a4%a7%e5%80%bc-uNEuepoMYY\">3. \u4f7f\u7528\u5b50\u67e5\u8a62\u7372\u53d6\u6700\u5927\u503c<\/h2>\n<p>\u6709\u6642\u5019\uff0c\u6211\u5011\u9700\u8981\u5728\u66f4\u8907\u96dc\u7684\u67e5\u8a62\u4e2d\u4f7f\u7528\u5b50\u67e5\u8a62\u4f86\u7372\u53d6\u6700\u5927\u503c\u3002\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u60f3\u8981\u67e5\u8a62\u85aa\u8cc7\u6700\u9ad8\u7684\u54e1\u5de5\u7684\u59d3\u540d\u548c\u85aa\u8cc7\uff0c\u6211\u5011\u53ef\u4ee5\u9019\u6a23\u505a\uff1a<\/p>\n<pre><code>SELECT name, salary\nFROM employees\nWHERE salary = (SELECT MAX(salary) FROM employees);<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u67e5\u8a62\u5c07\u8fd4\u56de\u85aa\u8cc7\u6700\u9ad8\u7684\u54e1\u5de5\u7684\u59d3\u540d\u548c\u85aa\u8cc7\uff0c\u9019\u5728\u9700\u8981\u7372\u53d6\u7279\u5b9a\u689d\u4ef6\u4e0b\u7684\u6700\u5927\u503c\u6642\u975e\u5e38\u6709\u7528\u3002<\/p>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95%e6%8f%90%e9%ab%98%e6%9f%a5%e8%a9%a2%e6%95%88%e7%8e%87-uNEuepoMYY\">4. \u4f7f\u7528\u7d22\u5f15\u63d0\u9ad8\u67e5\u8a62\u6548\u7387<\/h2>\n<p>\u5728\u5927\u578b\u6578\u64da\u5eab\u4e2d\uff0c\u67e5\u8a62\u6700\u5927\u503c\u7684\u6548\u7387\u53ef\u80fd\u6703\u53d7\u5230\u5f71\u97ff\u3002\u70ba\u4e86\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u53ef\u4ee5\u8003\u616e\u5728\u9700\u8981\u67e5\u8a62\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\u3002\u7d22\u5f15\u53ef\u4ee5\u52a0\u901f\u67e5\u8a62\u904e\u7a0b\uff0c\u7279\u5225\u662f\u5728\u6578\u64da\u91cf\u9f90\u5927\u7684\u60c5\u6cc1\u4e0b\u3002<\/p>\n<pre><code>CREATE INDEX idx_salary ON employees(salary);<\/code><\/pre>\n<p>\u5275\u5efa\u7d22\u5f15\u5f8c\uff0c\u67e5\u8a62\u6700\u5927\u503c\u7684\u901f\u5ea6\u5c07\u986f\u8457\u63d0\u9ad8\uff0c\u9019\u5c0d\u65bc\u9700\u8981\u983b\u7e41\u67e5\u8a62\u7684\u61c9\u7528\u5834\u666f\u5c24\u70ba\u91cd\u8981\u3002<\/p>\n<h2 id=\"5-%e4%bd%bf%e7%94%a8%e6%95%b8%e6%93%9a%e5%8f%af%e8%a6%96%e5%8c%96%e5%b7%a5%e5%85%b7%e5%b1%95%e7%a4%ba%e6%9c%80%e5%a4%a7%e5%80%bc-uNEuepoMYY\">5. \u4f7f\u7528\u6578\u64da\u53ef\u8996\u5316\u5de5\u5177\u5c55\u793a\u6700\u5927\u503c<\/h2>\n<p>\u9664\u4e86\u5728\u6578\u64da\u5eab\u4e2d\u67e5\u8a62\u6700\u5927\u503c\u5916\uff0c\u5c07\u9019\u4e9b\u6578\u64da\u53ef\u8996\u5316\u4e5f\u662f\u4e00\u500b\u6709\u6548\u7684\u8868\u9054\u65b9\u5f0f\u3002\u4f7f\u7528\u6578\u64da\u53ef\u8996\u5316\u5de5\u5177\uff08\u5982Tableau\u3001Power BI\u7b49\uff09\u53ef\u4ee5\u5c07\u6578\u64da\u4ee5\u5716\u8868\u7684\u5f62\u5f0f\u5c55\u793a\uff0c\u8b93\u4f7f\u7528\u8005\u66f4\u76f4\u89c0\u5730\u7406\u89e3\u6578\u64da\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528\u689d\u5f62\u5716\u6216\u6298\u7dda\u5716\u4f86\u5c55\u793a\u4e0d\u540c\u90e8\u9580\u7684\u6700\u9ad8\u85aa\u8cc7\uff0c\u9019\u6a23\u4e0d\u50c5\u80fd\u5920\u6e05\u6670\u5730\u8868\u9054\u6578\u64da\uff0c\u9084\u80fd\u5e6b\u52a9\u6c7a\u7b56\u8005\u505a\u51fa\u66f4\u660e\u667a\u7684\u9078\u64c7\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-uNEuepoMYY\">\u7e3d\u7d50<\/h2>\n<p>\u8868\u9054\u6578\u64da\u5eab\u7684\u66f4\u5927\u503c\u662f\u4e00\u500b\u591a\u65b9\u9762\u7684\u8ab2\u984c\uff0c\u6d89\u53ca\u5230SQL\u67e5\u8a62\u3001\u6578\u64da\u5206\u7d44\u3001\u5b50\u67e5\u8a62\u3001\u7d22\u5f15\u4ee5\u53ca\u6578\u64da\u53ef\u8996\u5316\u7b49\u591a\u7a2e\u6280\u8853\u3002\u901a\u904e\u5408\u7406\u904b\u7528\u9019\u4e9b\u65b9\u6cd5\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u7372\u53d6\u548c\u5c55\u793a\u6578\u64da\u5eab\u4e2d\u7684\u6700\u5927\u503c\uff0c\u5f9e\u800c\u70ba\u6578\u64da\u5206\u6790\u548c\u6c7a\u7b56\u63d0\u4f9b\u652f\u6301\u3002\u5982\u679c\u60a8\u9700\u8981\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u4f86\u63d0\u5347\u60a8\u7684\u6578\u64da\u8655\u7406\u80fd\u529b\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u6709\u6548\u8868\u9054\u548c\u67e5\u8a62\u66f4\u5927\u503c\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u548c\u7ba1\u7406\u7684\u6548\u7387\u8207\u6e96\u78ba\u6027\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-172563","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172563","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=172563"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172563\/revisions"}],"predecessor-version":[{"id":172564,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/172563\/revisions\/172564"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=172563"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=172563"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=172563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}