{"id":199905,"date":"2025-05-06T10:13:24","date_gmt":"2025-05-06T02:13:24","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199905\/"},"modified":"2025-05-06T10:13:24","modified_gmt":"2025-05-06T02:13:24","slug":"%e5%8e%bb%e9%99%a4oracle%e6%95%b0%e6%8d%ae%e5%ba%93%e4%b8%ad%e7%9a%84%e9%87%8d%e5%a4%8d%e6%95%b0%e6%8d%ae%ef%bc%9a%e4%bf%9d%e7%95%99%e5%94%af%e4%b8%80%e8%ae%b0%e5%bd%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199905\/","title":{"rendered":"\u53bb\u9664Oracle\u6570\u636e\u5e93\u4e2d\u7684\u91cd\u590d\u6570\u636e\uff1a\u4fdd\u7559\u552f\u4e00\u8bb0\u5f55"},"content":{"rendered":"

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

\u53bb\u9664Oracle\u6570\u636e\u5e93\u4e2d\u7684\u91cd\u590d\u6570\u636e\uff1a\u4fdd\u7559\u552f\u4e00\u8bb0\u5f55<\/h1>\n

\u5bf9\u4e8e\u4e00\u4e2a\u6570\u636e\u5e93\u5f00\u53d1\u8005\u6765\u8bf4\uff0c\u7262\u56fa\u624e\u5b9e\u7684\u57fa\u7840\u662f\u5341\u5206\u91cd\u8981\u7684\uff0c\u4e3b\u673a\u5b9d\u8d1d\u5c31\u6765\u5e26\u5927\u5bb6\u4e00\u70b9\u70b9\u7684\u638c\u63e1\u57fa\u7840\u77e5\u8bc6\u70b9\u3002\u4eca\u5929\u672c\u7bc7\u6587\u7ae0\u5e26\u5927\u5bb6\u4e86\u89e3\u300a\u53bb\u9664Oracle\u6570\u636e\u5e93\u4e2d\u7684\u91cd\u590d\u6570\u636e\uff1a\u4fdd\u7559\u552f\u4e00\u8bb0\u5f55\u300b\uff0c\u4e3b\u8981\u4ecb\u7ecd\u4e86\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u5feb\u70b9\u6536\u85cf\u8d77\u6765\u5427\uff0c\u5426\u5219\u9700\u8981\u65f6\u5c31\u627e\u4e0d\u5230\u4e86\uff01<\/p>\n

\u89e3\u51b3Oracle\u6570\u636e\u5e93\u91cd\u590d\u6570\u636e\u95ee\u9898\uff1a\u53ea\u53d6\u4e00\u6761\uff0c\u9700\u8981\u5177\u4f53\u4ee3\u7801\u793a\u4f8b<\/p>\n

\u5728\u6570\u636e\u5e93\u4e2d\uff0c\u91cd\u590d\u6570\u636e\u662f\u4e00\u4e2a\u5e38\u89c1\u7684\u95ee\u9898\uff0c\u53ef\u80fd\u4f1a\u5f71\u54cd\u6570\u636e\u7684\u51c6\u786e\u6027\u548c\u67e5\u8be2\u6548\u7387\u3002\u5728Oracle\u6570\u636e\u5e93\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u7f16\u5199SQL\u8bed\u53e5\u6765\u89e3\u51b3\u91cd\u590d\u6570\u636e\u7684\u95ee\u9898\uff0c\u53ea\u53d6\u4e00\u6761\u6570\u636e\u3002\u4e0b\u9762\u5c06\u4ecb\u7ecd\u4e00\u4e9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u6765\u89e3\u51b3\u8fd9\u4e00\u95ee\u9898\u3002<\/p>\n

    \n
  1. \u4f7f\u7528ROWID<\/li>\n<\/ol>\n

    ROWID\u662fOracle\u6570\u636e\u5e93\u4e2d\u6bcf\u4e00\u884c\u6570\u636e\u7684\u552f\u4e00\u6807\u8bc6\u7b26\uff0c\u53ef\u4ee5\u901a\u8fc7ROWID\u6765\u5224\u65ad\u6570\u636e\u662f\u5426\u91cd\u590d\uff0c\u7136\u540e\u53ea\u53d6\u5176\u4e2d\u4e00\u6761\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528ROWID\u89e3\u51b3\u91cd\u590d\u6570\u636e\u95ee\u9898\u7684\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n

    SELECT * FROM (\n  SELECT\n    t.*,\n    ROW_NUMBER() OVER (PARTITION BY t.column_name ORDER BY t.rowid) AS rn\n  FROM table_name t\n) WHERE rn = 1;<\/pre>\n
    \u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u5bf9\u6570\u636e\u6839\u636e\u6307\u5b9a\u7684\u5b57\u6bb5\u5217\u8fdb\u884c\u5206\u7ec4\uff0c\u7136\u540e\u4f7f\u7528ROW_NUMBER\u51fd\u6570\u7ed9\u6bcf\u4e00\u884c\u6570\u636e\u8fdb\u884c\u7f16\u53f7\u3002\u6700\u540e\uff0c\u53ea\u9009\u62e9\u7f16\u53f7\u4e3a1\u7684\u6570\u636e\uff0c\u4ece\u800c\u53ea\u53d6\u4e00\u6761\u91cd\u590d\u7684\u6570\u636e\u3002<\/p>\n
      \n
    1. \u4f7f\u7528\u5b50\u67e5\u8be2<\/li>\n<\/ol>\n
      \u53e6\u4e00\u79cd\u65b9\u6cd5\u662f\u901a\u8fc7\u5b50\u67e5\u8be2\u6765\u5b9e\u73b0\u53ea\u53d6\u4e00\u6761\u91cd\u590d\u6570\u636e\u7684\u76ee\u7684\uff0c\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n
      SELECT column_name1, column_name2, column_name3\nFROM table_name t\nWHERE t.rowid = (SELECT MIN(rowid) FROM table_name WHERE column_name1 = t.column_name1);<\/pre>\n
      \u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u901a\u8fc7\u5b50\u67e5\u8be2\u627e\u5230\u6bcf\u7ec4\u91cd\u590d\u6570\u636e\u4e2d\u7684\u6700\u5c0fROWID\uff0c\u7136\u540e\u518d\u6839\u636e\u8fd9\u4e2aROWID\u6765\u9009\u62e9\u5bf9\u5e94\u7684\u6570\u636e\uff0c\u4ece\u800c\u53ea\u53d6\u4e00\u6761\u91cd\u590d\u6570\u636e\u3002<\/p>\n
        \n
      1. \u4f7f\u7528GROUP BY<\/li>\n<\/ol>\n
        \u53e6\u4e00\u79cd\u65b9\u6cd5\u662f\u901a\u8fc7\u4f7f\u7528GROUP BY\u6765\u5206\u7ec4\u6570\u636e\uff0c\u7136\u540e\u518d\u9009\u62e9\u6bcf\u7ec4\u6570\u636e\u4e2d\u7684\u7b2c\u4e00\u6761\u6570\u636e\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n
        SELECT column_name1, column_name2, column_name3\nFROM (\n  SELECT column_name1, column_name2, column_name3, ROW_NUMBER() OVER (PARTITION BY column_name1 ORDER BY column_name1) AS rn\n  FROM table_name\n) WHERE rn = 1;<\/pre>\n
        \u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u6309\u7167\u6307\u5b9a\u7684\u5b57\u6bb5\u5217\u8fdb\u884c\u5206\u7ec4\uff0c\u7136\u540e\u518d\u4f7f\u7528ROW_NUMBER\u51fd\u6570\u5bf9\u6bcf\u7ec4\u6570\u636e\u8fdb\u884c\u7f16\u53f7\uff0c\u6700\u540e\u9009\u62e9\u7f16\u53f7\u4e3a1\u7684\u6570\u636e\uff0c\u4ece\u800c\u53ea\u53d6\u4e00\u6761\u91cd\u590d\u6570\u636e\u3002<\/p>\n
        \u603b\u7ed3\uff1a<\/p>\n
        \u901a\u8fc7\u4ee5\u4e0a\u51e0\u79cd\u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u89e3\u51b3Oracle\u6570\u636e\u5e93\u4e2d\u91cd\u590d\u6570\u636e\u7684\u95ee\u9898\uff0c\u53ea\u53d6\u4e00\u6761\u6570\u636e\u3002\u5177\u4f53\u9009\u62e9\u54ea\u79cd\u65b9\u6cd5\u53d6\u51b3\u4e8e\u6570\u636e\u91cf\u548c\u6027\u80fd\u8981\u6c42\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u53ef\u4ee5\u6839\u636e\u9700\u6c42\u9009\u62e9\u6700\u9002\u5408\u7684\u65b9\u6cd5\u6765\u5904\u7406\u91cd\u590d\u6570\u636e\uff0c\u786e\u4fdd\u6570\u636e\u7684\u51c6\u786e\u6027\u548c\u67e5\u8be2\u6548\u7387\u3002<\/p>\n
        \u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300a\u53bb\u9664Oracle\u6570\u636e\u5e93\u4e2d\u7684\u91cd\u590d\u6570\u636e\uff1a\u4fdd\u7559\u552f\u4e00\u8bb0\u5f55\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6570\u636e\u5e93\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n
        \n
        \n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
        \u53bb\u9664Oracle\u6570\u636e\u5e93\u4e2d\u7684\u91cd\u590d\u6570...<\/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-199905","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199905","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=199905"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199905\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199905"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199905"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}