{"id":168367,"date":"2024-11-06T11:47:19","date_gmt":"2024-11-06T03:47:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168367\/"},"modified":"2024-11-06T11:47:20","modified_gmt":"2024-11-06T03:47:20","slug":"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e7%9a%84%e7%99%be%e5%88%86%e6%af%94%e8%a8%88%e7%ae%97%e6%96%b9%e6%b3%95-sql-%e6%95%b8%e6%93%9a%e5%ba%ab-%e7%99%be%e5%88%86%e6%af%94","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168367\/","title":{"rendered":"SQL \u6578\u64da\u5eab\u4e2d\u7684\u767e\u5206\u6bd4\u8a08\u7b97\u65b9\u6cd5 (sql \u6578\u64da\u5eab \u767e\u5206\u6bd4)"},"content":{"rendered":"

SQL \u6578\u64da\u5eab\u4e2d\u7684\u767e\u5206\u6bd4\u8a08\u7b97\u65b9\u6cd5<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u767e\u5206\u6bd4\u8a08\u7b97\u662f\u4e00\u500b\u5e38\u898b\u4e14\u91cd\u8981\u7684\u64cd\u4f5c\u3002\u7121\u8ad6\u662f\u5728\u5831\u544a\u751f\u6210\u3001\u6578\u64da\u5206\u6790\u9084\u662f\u696d\u52d9\u6c7a\u7b56\u4e2d\uff0c\u4e86\u89e3\u5982\u4f55\u5728 SQL \u6578\u64da\u5eab\u4e2d\u9032\u884c\u767e\u5206\u6bd4\u8a08\u7b97\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5728 SQL \u6578\u64da\u5eab\u4e2d\u8a08\u7b97\u767e\u5206\u6bd4\u7684\u65b9\u6cd5\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n

\u767e\u5206\u6bd4\u8a08\u7b97\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n

\u767e\u5206\u6bd4\u662f\u8868\u793a\u67d0\u4e00\u6578\u91cf\u76f8\u5c0d\u65bc\u53e6\u4e00\u6578\u91cf\u7684\u6bd4\u4f8b\uff0c\u901a\u5e38\u4ee5 100 \u70ba\u57fa\u6e96\u3002\u4f8b\u5982\uff0c\u5982\u679c\u4e00\u500b\u73ed\u7d1a\u6709 20 \u540d\u5b78\u751f\uff0c\u5176\u4e2d 5 \u540d\u5b78\u751f\u901a\u904e\u4e86\u8003\u8a66\uff0c\u90a3\u9ebc\u901a\u904e\u7387\u53ef\u4ee5\u8a08\u7b97\u70ba\uff1a<\/p>\n

\u901a\u904e\u7387 = (\u901a\u904e\u7684\u5b78\u751f\u6578 \/ \u7e3d\u5b78\u751f\u6578) * 100<\/code><\/pre>\n
\u5728 SQL \u4e2d\uff0c\u9019\u7a2e\u8a08\u7b97\u53ef\u4ee5\u901a\u904e\u7c21\u55ae\u7684\u7b97\u8853\u904b\u7b97\u4f86\u5be6\u73fe\u3002<\/p>\n
\u5728 SQL \u4e2d\u8a08\u7b97\u767e\u5206\u6bd4<\/h2>\n
\u5728 SQL \u6578\u64da\u5eab\u4e2d\uff0c\u8a08\u7b97\u767e\u5206\u6bd4\u901a\u5e38\u6d89\u53ca\u5230\u4f7f\u7528\u805a\u5408\u51fd\u6578\uff08\u5982 COUNT\u3001SUM\uff09\u548c\u57fa\u672c\u7684\u7b97\u8853\u904b\u7b97\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u8a08\u7b97\u67d0\u500b\u8868\u4e2d\u67d0\u500b\u689d\u4ef6\u7684\u767e\u5206\u6bd4\u3002<\/p>\n
\u793a\u4f8b\uff1a\u8a08\u7b97\u901a\u904e\u7387<\/h3>\n
\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba students<\/code> \u7684\u8868\uff0c\u8a72\u8868\u5305\u542b\u5b78\u751f\u7684\u59d3\u540d\u548c\u4ed6\u5011\u7684\u8003\u8a66\u6210\u7e3e\u3002\u8981\u8a08\u7b97\u901a\u904e\u8003\u8a66\u7684\u5b78\u751f\u6240\u4f54\u7684\u767e\u5206\u6bd4\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u67e5\u8a62\uff1a<\/p>\n
SELECT \n    (COUNT(CASE WHEN score >= 60 THEN 1 END) * 100.0 \/ COUNT(*)) AS pass_rate\nFROM \n    students;<\/code><\/pre>\n
\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u4f7f\u7528\u4e86 COUNT<\/code> \u51fd\u6578\u4f86\u8a08\u7b97\u901a\u904e\u7684\u5b78\u751f\u6578\uff08\u5373\u6210\u7e3e\u5927\u65bc\u6216\u7b49\u65bc 60 \u7684\u5b78\u751f\uff09\uff0c\u7136\u5f8c\u5c07\u5176\u4e58\u4ee5 100\uff0c\u6700\u5f8c\u9664\u4ee5\u7e3d\u5b78\u751f\u6578\u4ee5\u7372\u5f97\u767e\u5206\u6bd4\u3002<\/p>\n
\u8a08\u7b97\u4e0d\u540c\u985e\u5225\u7684\u767e\u5206\u6bd4<\/h3>\n
\u5982\u679c\u6211\u5011\u60f3\u8981\u8a08\u7b97\u4e0d\u540c\u985e\u5225\uff08\u4f8b\u5982\u4e0d\u540c\u79d1\u76ee\u7684\u901a\u904e\u7387\uff09\uff0c\u53ef\u4ee5\u4f7f\u7528 GROUP BY<\/code> \u5b50\u53e5\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff1a<\/p>\n
SELECT \n    subject,\n    (COUNT(CASE WHEN score >= 60 THEN 1 END) * 100.0 \/ COUNT(*)) AS pass_rate\nFROM \n    students\nGROUP BY \n    subject;<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u79d1\u76ee\u7684\u901a\u904e\u7387\uff0c\u5e6b\u52a9\u6211\u5011\u4e86\u89e3\u4e0d\u540c\u79d1\u76ee\u7684\u5b78\u751f\u8868\u73fe\u3002<\/p>\n
\u4f7f\u7528\u8996\u5716\u9032\u884c\u767e\u5206\u6bd4\u8a08\u7b97<\/h2>\n
\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u60a8\u53ef\u80fd\u5e0c\u671b\u5c07\u767e\u5206\u6bd4\u8a08\u7b97\u5c01\u88dd\u5728\u4e00\u500b\u8996\u5716\u4e2d\uff0c\u4ee5\u4fbf\u65bc\u91cd\u8907\u4f7f\u7528\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u5275\u5efa\u4e00\u500b\u8996\u5716\u4f86\u8a08\u7b97\u901a\u904e\u7387\u7684\u793a\u4f8b\uff1a<\/p>\n
CREATE VIEW pass_rate_view AS\nSELECT \n    subject,\n    (COUNT(CASE WHEN score >= 60 THEN 1 END) * 100.0 \/ COUNT(*)) AS pass_rate\nFROM \n    students\nGROUP BY \n    subject;<\/code><\/pre>\n
\u5275\u5efa\u8996\u5716\u5f8c\uff0c\u60a8\u53ef\u4ee5\u8f15\u9b06\u67e5\u8a62\u901a\u904e\u7387\uff1a<\/p>\n
SELECT * FROM pass_rate_view;<\/code><\/pre>\n
\u7e3d\u7d50<\/h2>\n
\u5728 SQL \u6578\u64da\u5eab\u4e2d\u8a08\u7b97\u767e\u5206\u6bd4\u662f\u4e00\u500b\u975e\u5e38\u5be6\u7528\u7684\u6280\u80fd\uff0c\u7121\u8ad6\u662f\u5728\u6578\u64da\u5206\u6790\u9084\u662f\u5831\u544a\u751f\u6210\u4e2d\u90fd\u80fd\u767c\u63ee\u91cd\u8981\u4f5c\u7528\u3002\u901a\u904e\u4f7f\u7528\u805a\u5408\u51fd\u6578\u548c\u57fa\u672c\u7684\u7b97\u8853\u904b\u7b97\uff0c\u60a8\u53ef\u4ee5\u8f15\u9b06\u5730\u8a08\u7b97\u51fa\u6240\u9700\u7684\u767e\u5206\u6bd4\u3002\u9019\u4e9b\u6280\u8853\u4e0d\u50c5\u9069\u7528\u65bc\u5b78\u8853\u6210\u7e3e\u7684\u5206\u6790\uff0c\u4e5f\u53ef\u4ee5\u61c9\u7528\u65bc\u5404\u7a2e\u696d\u52d9\u5834\u666f\u4e2d\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u9700\u6c42\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u5e6b\u52a9\u60a8\u8f15\u9b06\u7ba1\u7406\u548c\u5206\u6790\u6578\u64da\u3002\u7121\u8ad6\u662f \u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e86\u89e3\u5982\u4f55\u5728 SQL \u6578\u64da\u5eab\u4e2d\u8a08\u7b97\u767e\u5206\u6bd4\uff0c\u638c\u63e1\u5e38\u7528\u7684 SQL \u67e5\u8a62\u6280\u5de7\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u80fd\u529b\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-168367","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168367","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=168367"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168367\/revisions"}],"predecessor-version":[{"id":168368,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168367\/revisions\/168368"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168367"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168367"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168367"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}