{"id":95826,"date":"2024-10-20T04:19:16","date_gmt":"2024-10-19T20:19:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/95826\/"},"modified":"2024-10-20T04:19:16","modified_gmt":"2024-10-19T20:19:16","slug":"oracle%e6%95%b8%e6%93%9a%e5%ba%ab%e9%9a%a8%e6%a9%9f%e6%9b%b4%e6%96%b0n%e6%a2%9d%e6%95%b8%e6%93%9a%e7%9a%84%e6%8a%80%e5%b7%a7-oracle%e9%9a%a8%e6%a9%9f%e6%9b%b4%e6%96%b0n%e6%a2%9d%e6%95%b8%e6%93%9a","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/95826\/","title":{"rendered":"Oracle\u6578\u64da\u5eab\u96a8\u6a5f\u66f4\u65b0n\u689d\u6578\u64da\u7684\u6280\u5de7 (oracle\u96a8\u6a5f\u66f4\u65b0n\u689d\u6578\u64da\u5eab)"},"content":{"rendered":"

Oracle\u6578\u64da\u5eab\u96a8\u6a5f\u66f4\u65b0n\u689d\u6578\u64da\u7684\u6280\u5de7<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u96a8\u6a5f\u66f4\u65b0\u6578\u64da\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\uff0c\u5c24\u5176\u662f\u5728\u6e2c\u8a66\u548c\u6578\u64da\u7dad\u8b77\u7684\u904e\u7a0b\u4e2d\u3002Oracle\u6578\u64da\u5eab\u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u5be6\u73fe\u96a8\u6a5f\u66f4\u65b0n\u689d\u6578\u64da\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u6709\u6548\u7684\u6280\u5de7\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u66f4\u9ad8\u6548\u5730\u9032\u884c\u6578\u64da\u66f4\u65b0\u3002<\/p>\n

1. \u4f7f\u7528ROWNUM\u96a8\u6a5f\u9078\u64c7\u6578\u64da<\/h2>\n

\u5728Oracle\u4e2d\uff0c\u53ef\u4ee5\u5229\u7528ROWNUM\u4f86\u96a8\u6a5f\u9078\u64c7\u9700\u8981\u66f4\u65b0\u7684\u6578\u64da\u884c\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u96a8\u6a5f\u9078\u64c7n\u689d\u6578\u64da\u4e26\u9032\u884c\u66f4\u65b0\uff1a<\/p>\n

UPDATE your_table\nSET your_column = 'new_value'\nWHERE ROWNUM <= n\nAND your_condition;\n<\/code><\/pre>\n
\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0cyour_table<\/code>\u662f\u8981\u66f4\u65b0\u7684\u8868\u540d\uff0cyour_column<\/code>\u662f\u9700\u8981\u66f4\u65b0\u7684\u5217\uff0cnew_value<\/code>\u662f\u65b0\u7684\u503c\uff0cn<\/code>\u662f\u8981\u66f4\u65b0\u7684\u884c\u6578\uff0cyour_condition<\/code>\u662f\u66f4\u65b0\u7684\u689d\u4ef6\u3002<\/p>\n
2. \u4f7f\u7528ORDER BY\u548cDBMS_RANDOM<\/h2>\n
\u53e6\u4e00\u7a2e\u65b9\u6cd5\u662f\u4f7f\u7528DBMS_RANDOM<\/code>\u5305\u4f86\u96a8\u6a5f\u6392\u5e8f\u6578\u64da\uff0c\u7136\u5f8c\u9078\u64c7\u524dn\u689d\u9032\u884c\u66f4\u65b0\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u78ba\u4fdd\u9078\u64c7\u7684\u6578\u64da\u662f\u96a8\u6a5f\u7684\uff0c\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u78bc\uff1a<\/p>\n
UPDATE (SELECT your_column\nFROM your_table\nWHERE your_condition\nORDER BY DBMS_RANDOM.VALUE)\nSET your_column = 'new_value'\nWHERE ROWNUM <= n;\n<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u9996\u5148\u5f9eyour_table<\/code>\u4e2d\u96a8\u6a5f\u9078\u64c7\u7b26\u5408\u689d\u4ef6\u7684\u6578\u64da\uff0c\u7136\u5f8c\u66f4\u65b0\u524dn\u689d\u6578\u64da\u3002<\/p>\n
3. \u4f7f\u7528CTE\uff08\u516c\u7528\u8868\u8868\u9054\u5f0f\uff09<\/h2>\n
\u516c\u7528\u8868\u8868\u9054\u5f0f\uff08CTE\uff09\u4e5f\u53ef\u4ee5\u7528\u4f86\u96a8\u6a5f\u66f4\u65b0\u6578\u64da\u3002\u9019\u7a2e\u65b9\u6cd5\u7684\u512a\u52e2\u5728\u65bc\u53ef\u8b80\u6027\u548c\u53ef\u7dad\u8b77\u6027\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528CTE\u7684\u793a\u4f8b\uff1a<\/p>\n
WITH random_rows AS (\n    SELECT your_column\n    FROM your_table\n    WHERE your_condition\n    ORDER BY DBMS_RANDOM.VALUE\n)\nUPDATE random_rows\nSET your_column = 'new_value'\nWHERE ROWNUM <= n;\n<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u9996\u5148\u5b9a\u7fa9\u4e86\u4e00\u500bCTE\uff0c\u96a8\u6a5f\u9078\u64c7\u7b26\u5408\u689d\u4ef6\u7684\u6578\u64da\uff0c\u7136\u5f8c\u5c0d\u9019\u4e9b\u6578\u64da\u9032\u884c\u66f4\u65b0\u3002<\/p>\n
4. \u4f7f\u7528PL\/SQL\u9032\u884c\u6279\u91cf\u66f4\u65b0<\/h2>\n
\u5982\u679c\u9700\u8981\u66f4\u65b0\u7684\u6578\u64da\u91cf\u8f03\u5927\uff0c\u53ef\u4ee5\u8003\u616e\u4f7f\u7528PL\/SQL\u9032\u884c\u6279\u91cf\u66f4\u65b0\u3002\u9019\u6a23\u53ef\u4ee5\u63d0\u9ad8\u6027\u80fd\u4e26\u6e1b\u5c11\u9396\u5b9a\u6642\u9593\u3002\u4ee5\u4e0b\u662f\u4e00\u500bPL\/SQL\u7684\u793a\u4f8b\uff1a<\/p>\n
DECLARE\n    CURSOR c_random IS\n        SELECT your_column\n        FROM your_table\n        WHERE your_condition\n        ORDER BY DBMS_RANDOM.VALUE;\n    v_row your_table%ROWTYPE;\nBEGIN\n    FOR i IN 1..n LOOP\n        FETCH c_random INTO v_row;\n        EXIT WHEN c_random%NOTFOUND;\n        UPDATE your_table\n        SET your_column = 'new_value'\n        WHERE CURRENT OF c_random;\n    END LOOP;\n    COMMIT;\nEND;\n<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u4f7f\u7528\u6e38\u6a19\u96a8\u6a5f\u9078\u64c7\u6578\u64da\u4e26\u9032\u884c\u66f4\u65b0\uff0c\u9069\u5408\u9700\u8981\u66f4\u65b0\u5927\u91cf\u6578\u64da\u7684\u60c5\u6cc1\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u96a8\u6a5f\u66f4\u65b0Oracle\u6578\u64da\u5eab\u4e2d\u7684n\u689d\u6578\u64da\u53ef\u4ee5\u901a\u904e\u591a\u7a2e\u65b9\u6cd5\u5be6\u73fe\uff0c\u5305\u62ec\u4f7f\u7528ROWNUM\u3001DBMS_RANDOM\u3001CTE\u548cPL\/SQL\u7b49\u6280\u8853\u3002\u6839\u64da\u5177\u9ad4\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u63d0\u9ad8\u6578\u64da\u66f4\u65b0\u7684\u6548\u7387\u548c\u9748\u6d3b\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u7528\u6236\uff0c\u9078\u64c7\u5408\u9069\u7684VPS<\/a><\/code>\u89e3\u6c7a\u65b9\u6848\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u6574\u9ad4\u6027\u80fd\uff0c\u7279\u5225\u662f\u5728\u9999\u6e2f\u5730\u5340\u7684\u6578\u64da\u7ba1\u7406\u9700\u6c42\u4e2d\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u638c\u63e1Oracle\u6578\u64da\u5eab\u96a8\u6a5f\u66f4\u65b0n\u689d\u6578\u64da\u7684\u6280\u5de7\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u6548\u7387\uff0c\u512a\u5316\u67e5\u8a62\u6027\u80fd\uff0c\u5be6\u73fe\u9748\u6d3b\u6578\u64da\u64cd\u4f5c\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-95826","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95826","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=95826"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95826\/revisions"}],"predecessor-version":[{"id":95827,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95826\/revisions\/95827"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=95826"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=95826"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=95826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}