{"id":179862,"date":"2024-11-09T05:25:18","date_gmt":"2024-11-08T21:25:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179862\/"},"modified":"2024-11-09T05:25:19","modified_gmt":"2024-11-08T21:25:19","slug":"%e5%a6%82%e4%bd%95%e5%9c%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e6%b1%82%e5%b7%ae%e9%9b%86%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e6%b1%82%e5%b7%ae%e9%9b%86","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179862\/","title":{"rendered":"\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u6c42\u5dee\u96c6\uff1f (\u6578\u64da\u5eab\u4e2d\u6c42\u5dee\u96c6)"},"content":{"rendered":"

\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u6c42\u5dee\u96c6\uff1f<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5dee\u96c6\u662f\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u5c24\u5176\u662f\u5728\u8655\u7406\u591a\u500b\u6578\u64da\u96c6\u6642\u3002\u5dee\u96c6\u7684\u4e3b\u8981\u76ee\u7684\u662f\u627e\u51fa\u5728\u4e00\u500b\u6578\u64da\u96c6\u4e2d\u5b58\u5728\u4f46\u5728\u53e6\u4e00\u500b\u6578\u64da\u96c6\u4e2d\u4e0d\u5b58\u5728\u7684\u6578\u64da\u3002\u9019\u5728\u6578\u64da\u5206\u6790\u3001\u5831\u544a\u751f\u6210\u548c\u6578\u64da\u6e05\u7406\u7b49\u65b9\u9762\u90fd\u975e\u5e38\u6709\u7528\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u6c42\u5dee\u96c6\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n

\u5dee\u96c6\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n

\u5dee\u96c6\u662f\u96c6\u5408\u8ad6\u4e2d\u7684\u4e00\u500b\u57fa\u672c\u64cd\u4f5c\uff0c\u5c0d\u65bc\u6578\u64da\u5eab\u4f86\u8aaa\uff0c\u5dee\u96c6\u64cd\u4f5c\u53ef\u4ee5\u7528\u4f86\u6bd4\u8f03\u5169\u500b\u6216\u591a\u500b\u8868\u4e2d\u7684\u6578\u64da\u3002\u5047\u8a2d\u6709\u5169\u500b\u8868 A \u548c B\uff0c\u5dee\u96c6 A – B \u5c07\u8fd4\u56de\u6240\u6709\u5728 A \u4e2d\u4f46\u4e0d\u5728 B \u4e2d\u7684\u8a18\u9304\u3002<\/p>\n

\u4f7f\u7528 SQL \u6c42\u5dee\u96c6<\/h2>\n

\u5728 SQL \u4e2d\uff0c\u6c42\u5dee\u96c6\u901a\u5e38\u53ef\u4ee5\u901a\u904e\u4f7f\u7528 EXCEPT<\/code> \u95dc\u9375\u5b57\u4f86\u5be6\u73fe\u3002\u4ee5\u4e0b\u662f\u57fa\u672c\u7684\u8a9e\u6cd5\uff1a<\/p>\n

SELECT column1, column2, ...\nFROM tableA\nEXCEPT\nSELECT column1, column2, ...\nFROM tableB;<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u6240\u6709\u5728 tableA<\/code> \u4e2d\u5b58\u5728\u4f46\u5728 tableB<\/code> \u4e2d\u4e0d\u5b58\u5728\u7684\u8a18\u9304\u3002<\/p>\n
\u793a\u4f8b<\/h3>\n
\u5047\u8a2d\u6211\u5011\u6709\u5169\u500b\u8868\uff0cstudents<\/code> \u548c graduated_students<\/code>\uff0c\u6211\u5011\u5e0c\u671b\u627e\u51fa\u6240\u6709\u5c1a\u672a\u7562\u696d\u7684\u5b78\u751f\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u67e5\u8a62\uff1a<\/p>\n
SELECT student_id, student_name\nFROM students\nEXCEPT\nSELECT student_id, student_name\nFROM graduated_students;<\/code><\/pre>\n
\u9019\u5c07\u8fd4\u56de\u6240\u6709\u5728 students<\/code> \u8868\u4e2d\u4f46\u4e0d\u5728 graduated_students<\/code> \u8868\u4e2d\u7684\u5b78\u751f\u3002<\/p>\n
\u4f7f\u7528 LEFT JOIN \u4f86\u6c42\u5dee\u96c6<\/h2>\n
\u9664\u4e86\u4f7f\u7528 EXCEPT<\/code>\uff0c\u6211\u5011\u9084\u53ef\u4ee5\u4f7f\u7528 LEFT JOIN<\/code> \u4f86\u5be6\u73fe\u5dee\u96c6\u3002\u9019\u7a2e\u65b9\u6cd5\u7684\u57fa\u672c\u601d\u8def\u662f\u5c07\u5169\u500b\u8868\u9032\u884c\u9023\u63a5\uff0c\u7136\u5f8c\u904e\u6ffe\u51fa\u90a3\u4e9b\u5728\u7b2c\u4e8c\u500b\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\u3002<\/p>\n
SELECT a.student_id, a.student_name\nFROM students a\nLEFT JOIN graduated_students b ON a.student_id = b.student_id\nWHERE b.student_id IS NULL;<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u6240\u6709\u5728 students<\/code> \u8868\u4e2d\u4f46\u4e0d\u5728 graduated_students<\/code> \u8868\u4e2d\u7684\u5b78\u751f\uff0c\u8207\u524d\u9762\u7684 EXCEPT<\/code> \u67e5\u8a62\u7d50\u679c\u76f8\u540c\u3002<\/p>\n
\u4f7f\u7528 NOT IN \u4f86\u6c42\u5dee\u96c6<\/h2>\n
\u53e6\u4e00\u7a2e\u6c42\u5dee\u96c6\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 NOT IN<\/code> \u5b50\u53e5\u3002\u9019\u7a2e\u65b9\u6cd5\u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n
SELECT student_id, student_name\nFROM students\nWHERE student_id NOT IN (SELECT student_id FROM graduated_students);<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u5c07\u8fd4\u56de\u6240\u6709\u5728 students<\/code> \u8868\u4e2d\u4f46\u4e0d\u5728 graduated_students<\/code> \u8868\u4e2d\u7684\u5b78\u751f\u3002\u9019\u7a2e\u65b9\u6cd5\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u53ef\u80fd\u6703\u6bd4 EXCEPT<\/code> \u548c LEFT JOIN<\/code> \u66f4\u76f4\u89c0\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728\u6578\u64da\u5eab\u4e2d\u6c42\u5dee\u96c6\u662f\u4e00\u500b\u5e38\u898b\u7684\u64cd\u4f5c\uff0c\u53ef\u4ee5\u901a\u904e\u591a\u7a2e\u65b9\u6cd5\u5be6\u73fe\uff0c\u5305\u62ec\u4f7f\u7528 EXCEPT<\/code>\u3001LEFT JOIN<\/code> \u548c NOT IN<\/code>\u3002\u6839\u64da\u5177\u9ad4\u7684\u9700\u6c42\u548c\u6578\u64da\u5eab\u7684\u8a2d\u8a08\uff0c\u9078\u64c7\u6700\u5408\u9069\u7684\u65b9\u6cd5\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u7684\u6548\u7387\u548c\u53ef\u8b80\u6027\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528 \u9999\u6e2fVPS<\/a> \u4f86\u6258\u7ba1\u60a8\u7684\u6578\u64da\u5eab\u3002\u7121\u8ad6\u662f\u9700\u8981\u9ad8\u6027\u80fd\u7684 \u4e91\u4f3a\u670d\u5668<\/a> \u9084\u662f\u7a69\u5b9a\u7684 \u4f3a\u670d\u5668<\/a>\uff0cServer.HK \u90fd\u80fd\u63d0\u4f9b\u6eff\u8db3\u60a8\u9700\u6c42\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5b78\u7fd2\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u6c42\u5dee\u96c6\uff0c\u638c\u63e1\u4f7f\u7528SQL\u67e5\u8a62\u8a9e\u53e5\u6709\u6548\u63d0\u53d6\u4e0d\u540c\u6578\u64da\u96c6\u4e4b\u9593\u7684\u5dee\u7570\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-179862","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179862","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=179862"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179862\/revisions"}],"predecessor-version":[{"id":179863,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179862\/revisions\/179863"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179862"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179862"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179862"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}