{"id":166593,"date":"2024-11-05T17:33:57","date_gmt":"2024-11-05T09:33:57","guid":{"rendered":"https:\/\/server.hk\/cnblog\/166593\/"},"modified":"2024-11-05T17:33:58","modified_gmt":"2024-11-05T09:33:58","slug":"%e5%bf%ab%e9%80%9f%e5%ad%b8%e6%9c%83%e6%9f%a5%e6%89%be%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e7%9a%84%e6%9b%b4%e5%a4%a7%e5%80%bc-%e6%9f%a5%e6%89%be%e6%9f%90%e5%80%8b%e6%95%b8%e6%93%9a%e5%ba%ab","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/166593\/","title":{"rendered":"\u5feb\u901f\u5b78\u6703\u67e5\u627e\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u66f4\u5927\u503c (\u67e5\u627e\u67d0\u500b\u6578\u64da\u5eab\u5b57\u6bb5\u66f4\u5927\u503c)"},"content":{"rendered":"

\u5feb\u901f\u5b78\u6703\u67e5\u627e\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u66f4\u5927\u503c<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u67e5\u627e\u67d0\u500b\u5b57\u6bb5\u7684\u6700\u5927\u503c\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u5728\u9032\u884c\u6578\u64da\u5206\u6790\u3001\u5831\u544a\u751f\u6210\uff0c\u9084\u662f\u6578\u64da\u6e05\u7406\u904e\u7a0b\u4e2d\uff0c\u80fd\u5920\u5feb\u901f\u6709\u6548\u5730\u7372\u53d6\u5b57\u6bb5\u7684\u6700\u5927\u503c\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u5982\u4f55\u5728\u4e0d\u540c\u7684\u6578\u64da\u5eab\u7cfb\u7d71\u4e2d\u67e5\u627e\u5b57\u6bb5\u7684\u6700\u5927\u503c\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n

\u4f7f\u7528 SQL \u67e5\u627e\u6700\u5927\u503c<\/h2>\n

SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u6700\u5e38\u7528\u7684\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u8a00\u4e4b\u4e00\u3002\u8981\u67e5\u627e\u67d0\u500b\u5b57\u6bb5\u7684\u6700\u5927\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528 MAX()<\/code> \u51fd\u6578\u3002\u4ee5\u4e0b\u662f\u57fa\u672c\u7684 SQL \u8a9e\u6cd5\uff1a<\/p>\n

SELECT MAX(\u5b57\u6bb5\u540d) AS \u6700\u5927\u503c\nFROM \u8868\u540d;<\/code><\/pre>\n
\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba employees<\/code> \u7684\u8868\uff0c\u4e26\u4e14\u6211\u5011\u60f3\u67e5\u627e salary<\/code> \u5b57\u6bb5\u7684\u6700\u5927\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n
SELECT MAX(salary) AS \u6700\u5927\u85aa\u8cc7\nFROM employees;<\/code><\/pre>\n
\u591a\u689d\u4ef6\u67e5\u8a62\u4e2d\u7684\u6700\u5927\u503c<\/h2>\n
\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u6211\u5011\u53ef\u80fd\u9700\u8981\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u4f86\u67e5\u627e\u6700\u5927\u503c\u3002\u9019\u6642\u53ef\u4ee5\u4f7f\u7528 WHERE<\/code> \u5b50\u53e5\u4f86\u9650\u5236\u67e5\u8a62\u7684\u7bc4\u570d\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u53ea\u60f3\u67e5\u627e\u90e8\u9580\u70ba\u300c\u92b7\u552e\u300d\u7684\u54e1\u5de5\u7684\u6700\u9ad8\u85aa\u8cc7\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n
SELECT MAX(salary) AS \u6700\u5927\u85aa\u8cc7\nFROM employees\nWHERE department = '\u92b7\u552e';<\/code><\/pre>\n
\u4f7f\u7528 GROUP BY \u67e5\u627e\u5206\u7d44\u7684\u6700\u5927\u503c<\/h2>\n
\u5982\u679c\u9700\u8981\u67e5\u627e\u6bcf\u500b\u90e8\u9580\u7684\u6700\u9ad8\u85aa\u8cc7\uff0c\u53ef\u4ee5\u4f7f\u7528 GROUP BY<\/code> \u5b50\u53e5\u3002\u9019\u6a23\u53ef\u4ee5\u5c07\u7d50\u679c\u6309\u90e8\u9580\u5206\u7d44\uff0c\u4e26\u67e5\u627e\u6bcf\u500b\u90e8\u9580\u7684\u6700\u5927\u85aa\u8cc7\uff1a<\/p>\n
SELECT department, MAX(salary) AS \u6700\u5927\u85aa\u8cc7\nFROM employees\nGROUP BY department;<\/code><\/pre>\n
\u5728 NoSQL \u6578\u64da\u5eab\u4e2d\u7684\u67e5\u627e\u65b9\u6cd5<\/h2>\n
\u9664\u4e86\u50b3\u7d71\u7684\u95dc\u4fc2\u578b\u6578\u64da\u5eab\uff0c\u8a31\u591a\u61c9\u7528\u7a0b\u5e8f\u4e5f\u4f7f\u7528 NoSQL \u6578\u64da\u5eab\uff0c\u5982 MongoDB\u3002\u5728 MongoDB \u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u805a\u5408\u6846\u67b6\u4f86\u67e5\u627e\u6700\u5927\u503c\u3002\u4ee5\u4e0b\u662f\u67e5\u627e\u67d0\u500b\u5b57\u6bb5\u6700\u5927\u503c\u7684\u793a\u4f8b\uff1a<\/p>\n
db.employees.aggregate([\n    { $group: { _id: \"$department\", \u6700\u5927\u85aa\u8cc7: { $max: \"$salary\" } } }\n]);<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u5c07\u6839\u64da\u90e8\u9580\u5206\u7d44\uff0c\u4e26\u67e5\u627e\u6bcf\u500b\u90e8\u9580\u7684\u6700\u9ad8\u85aa\u8cc7\u3002<\/p>\n
\u6027\u80fd\u8003\u91cf<\/h2>\n
\u5728\u67e5\u627e\u6700\u5927\u503c\u6642\uff0c\u6027\u80fd\u662f\u4e00\u500b\u91cd\u8981\u7684\u8003\u91cf\u56e0\u7d20\u3002\u5c0d\u65bc\u5927\u578b\u6578\u64da\u96c6\uff0c\u4f7f\u7528\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u78ba\u4fdd\u5728\u9700\u8981\u67e5\u627e\u6700\u5927\u503c\u7684\u5b57\u6bb5\u4e0a\u5efa\u7acb\u7d22\u5f15\uff0c\u9019\u6a23\u53ef\u4ee5\u52a0\u5feb\u67e5\u8a62\u901f\u5ea6\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u67e5\u627e\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u6700\u5927\u503c\u662f\u4e00\u9805\u57fa\u672c\u800c\u91cd\u8981\u7684\u6280\u80fd\uff0c\u7121\u8ad6\u662f\u5728\u6578\u64da\u5206\u6790\u9084\u662f\u65e5\u5e38\u6578\u64da\u7ba1\u7406\u4e2d\u3002\u901a\u904e\u4f7f\u7528 SQL \u7684 MAX()<\/code> \u51fd\u6578\u3001WHERE<\/code> \u5b50\u53e5\u548c GROUP BY<\/code> \u5b50\u53e5\uff0c\u6216\u5728 NoSQL \u6578\u64da\u5eab\u4e2d\u4f7f\u7528\u805a\u5408\u6846\u67b6\uff0c\u60a8\u90fd\u53ef\u4ee5\u6709\u6548\u5730\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6027\u80fd\u7684\u61c9\u7528\uff0c\u8a18\u5f97\u5728\u76f8\u95dc\u5b57\u6bb5\u4e0a\u5efa\u7acb\u7d22\u5f15\uff0c\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 \u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u64cd\u4f5c\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u3002\u7121\u8ad6\u662f\u5c0f\u578b\u9805\u76ee\u9084\u662f\u5927\u578b\u4f01\u696d\u61c9\u7528\uff0c\u6211\u5011\u7684 \u4e91\u670d\u52a1\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u6027\u80fd\u548c\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5feb\u901f\u5b78\u6703\u5982\u4f55\u67e5\u627e\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u66f4\u5927\u503c\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u6548\u7387\uff0c\u7c21\u5316\u67e5\u8a62\u904e\u7a0b\uff0c\u52a9\u4f60\u8f15\u9b06\u7372\u53d6\u6240\u9700\u4fe1\u606f\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-166593","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/166593","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=166593"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/166593\/revisions"}],"predecessor-version":[{"id":166594,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/166593\/revisions\/166594"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=166593"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=166593"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=166593"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}