{"id":200501,"date":"2025-05-06T12:18:32","date_gmt":"2025-05-06T04:18:32","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200501\/"},"modified":"2025-05-06T12:18:32","modified_gmt":"2025-05-06T04:18:32","slug":"mysql%e5%ad%90%e6%9f%a5%e8%af%a2%e6%8e%92%e5%ba%8f%e5%a4%b1%e6%95%88%e5%a6%82%e4%bd%95%e8%a7%a3%e5%86%b3%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200501\/","title":{"rendered":"MySQL\u5b50\u67e5\u8be2\u6392\u5e8f\u5931\u6548\u5982\u4f55\u89e3\u51b3\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

MySQL\u5b50\u67e5\u8be2\u6392\u5e8f\u5931\u6548\u5982\u4f55\u89e3\u51b3\uff1f<\/h1>\n

\u4e00\u5206\u8015\u8018\uff0c\u4e00\u5206\u6536\u83b7\uff01\u65e2\u7136\u6253\u5f00\u4e86\u8fd9\u7bc7\u6587\u7ae0\uff0c\u5c31\u575a\u6301\u770b\u4e0b\u53bb\u5427\uff01\u6587\u4e2d\u5185\u5bb9\u5305\u542b\u7b49\u7b49\u77e5\u8bc6\u70b9…\u5e0c\u671b\u4f60\u80fd\u5728\u9605\u8bfb\u672c\u6587\u540e\uff0c\u80fd\u771f\u771f\u5b9e\u5b9e\u5b66\u5230\u77e5\u8bc6\u6216\u8005\u5e2e\u4f60\u89e3\u51b3\u5fc3\u4e2d\u7684\u7591\u60d1\uff0c\u4e5f\u6b22\u8fce\u5927\u4f6c\u6216\u8005\u65b0\u4eba\u670b\u53cb\u4eec\u591a\u7559\u8a00\u8bc4\u8bba\uff0c\u591a\u7ed9\u5efa\u8bae\uff01\u8c22\u8c22\uff01<\/p>\n

<\/p>\n

mysql\u5b50\u67e5\u8be2\u6392\u5e8f\u5931\u6548\u7684\u89e3\u51b3\u65b9\u6848<\/strong><\/p>\n

\u6570\u636e\u5e93\u4e2d\u5b58\u50a8\u7740\u5927\u91cf\u7528\u6237\u6570\u636e\uff0c\u6709\u65f6\u6211\u4eec\u9700\u8981\u4ece\u8fd9\u4e9b\u6570\u636e\u4e2d\u627e\u51fa\u540c\u4e00\u4e2a\u7528\u6237\u5bf9\u540c\u4e00\u4e2a\u4ea7\u54c1\u7684\u6700\u65b0\u8bb0\u5f55\u3002\u7136\u800c\uff0c\u5f53\u6211\u4eec\u76f4\u63a5\u5bf9\u5b50\u67e5\u8be2\u8fdb\u884c\u6392\u5e8f\u65f6\uff0c\u6392\u5e8f\u7ed3\u679c\u53ef\u80fd\u4e0d\u7b26\u5408\u9884\u671f\u3002<\/p>\n

\u95ee\u9898\u539f\u56e0<\/strong><\/p>\n

\u5728mysql\u4e2d\uff0c\u5b50\u67e5\u8be2\u4e2d\u7684\u6392\u5e8f\u4e0d\u4f1a\u4fdd\u7559\u5230\u5916\u90e8\u67e5\u8be2\u4e2d\u3002\u56e0\u6b64\uff0c\u5f53\u6211\u4eec\u5bf9\u4e00\u4e2a\u5305\u542b\u6392\u5e8f\u5b50\u67e5\u8be2\u7684\u5916\u90e8\u67e5\u8be2\u8fdb\u884c\u5206\u7ec4\u65f6\uff0c\u6392\u5e8f\u5c06\u5931\u6548\u3002<\/p>\n

\u89e3\u51b3\u65b9\u6cd5<\/strong><\/p>\n

\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u4e00\u79cd\u53cc\u91cd\u67e5\u8be2\u7684\u65b9\u6cd5\uff1a<\/p>\n

    \n
  1. \u8ba1\u7b97\u6bcf\u4e2a\u5206\u7ec4\u7684\u6700\u5927\u65f6\u95f4\u6233<\/strong><\/li>\n<\/ol>\n
    select\n  max(create_time) as max_create_time,\n  user_id,\n  product_id\nfrom\n  demo\ngroup by\n  user_id,\n  product_id<\/pre>\n
      \n
    1. \u4f7f\u7528\u6700\u5927\u65f6\u95f4\u6233\u5173\u8054\u539f\u8868<\/strong><\/li>\n<\/ol>\n
      SELECT\n  t2.id,\n  t1.*\nFROM\n  (\n    SELECT\n      *\n    FROM\n      demo\n    ORDER BY\n      create_time DESC\n  ) AS t2\nJOIN\n  (\n    SELECT\n      MAX(create_time) AS max_create_time,\n      user_id,\n      product_id\n    FROM\n      demo\n    GROUP BY\n      user_id,\n      product_id\n  ) AS t1\n  ON t1.user_id = t2.user_id\n  AND t1.product_id = t2.product_id\n  AND t1.max_create_time = t2.create_time<\/pre>\n
      \u89e3\u91ca<\/strong><\/p>\n
      \u8be5\u89e3\u51b3\u65b9\u6cd5\u901a\u8fc7\u4e24\u6b21\u67e5\u8be2\u5b9e\u73b0\uff1a<\/p>\n
        \n
      • \u7b2c\u4e00\u4e2a\u67e5\u8be2<\/strong>\u8ba1\u7b97\u6bcf\u4e2a\u5206\u7ec4\u7684\u6700\u65b0\u65f6\u95f4\u6233\u3002<\/li>\n
      • \u7b2c\u4e8c\u4e2a\u67e5\u8be2<\/strong>\u4f7f\u7528\u8be5\u65f6\u95f4\u6233\u4f5c\u4e3a\u8fde\u63a5\u6761\u4ef6\uff0c\u4ece\u539f\u8868\u4e2d\u627e\u51fa\u6bcf\u4e2a\u5206\u7ec4\u7684\u6700\u65b0\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n
        \u8fd9\u6837\uff0c\u6211\u4eec\u53ef\u4ee5\u83b7\u5f97\u540c\u4e00\u4e2a\u7528\u6237\u5bf9\u540c\u4e00\u4e2a\u4ea7\u54c1\u7684\u6700\u65b0\u8bb0\u5f55\uff0c\u6392\u5e8f\u7ed3\u679c\u4e5f\u7b26\u5408\u9884\u671f\u3002<\/p>\n
        \u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300aMySQL\u5b50\u67e5\u8be2\u6392\u5e8f\u5931\u6548\u5982\u4f55\u89e3\u51b3\uff1f\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n
        \n
        \n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
        MySQL\u5b50\u67e5\u8be2\u6392\u5e8f\u5931\u6548\u5982\u4f55\u89e3\u51b3...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200501","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200501","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200501"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200501\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200501"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200501"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200501"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}