{"id":168171,"date":"2024-11-06T10:06:19","date_gmt":"2024-11-06T02:06:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168171\/"},"modified":"2024-11-06T10:06:19","modified_gmt":"2024-11-06T02:06:19","slug":"%e5%85%ad%e7%a8%aesql-server%e5%88%aa%e9%99%a4%e9%87%8d%e8%a4%87%e8%a1%8c%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168171\/","title":{"rendered":"\u516d\u7a2eSQL Server\u522a\u9664\u91cd\u8907\u884c\u7684\u65b9\u6cd5"},"content":{"rendered":"

\u516d\u7a2eSQL Server\u522a\u9664\u91cd\u8907\u884c\u7684\u65b9\u6cd5<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u91cd\u8907\u884c\u7684\u5b58\u5728\u53ef\u80fd\u6703\u5c0e\u81f4\u6578\u64da\u4e0d\u4e00\u81f4\u6027\u548c\u67e5\u8a62\u6548\u7387\u7684\u964d\u4f4e\u3002\u56e0\u6b64\uff0c\u522a\u9664\u91cd\u8907\u884c\u662f\u7dad\u8b77\u6578\u64da\u5eab\u5065\u5eb7\u7684\u91cd\u8981\u6b65\u9a5f\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u516d\u7a2e\u5728SQL Server\u4e2d\u522a\u9664\u91cd\u8907\u884c\u7684\u65b9\u6cd5\uff0c\u5e6b\u52a9\u60a8\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u3002<\/p>\n

\u65b9\u6cd5\u4e00\uff1a\u4f7f\u7528ROW_NUMBER()\u51fd\u6578<\/h2>\n

ROW_NUMBER()\u51fd\u6578\u53ef\u4ee5\u70ba\u6bcf\u4e00\u884c\u5206\u914d\u4e00\u500b\u552f\u4e00\u7684\u5e8f\u865f\uff0c\u7136\u5f8c\u6839\u64da\u9019\u500b\u5e8f\u865f\u4f86\u522a\u9664\u91cd\u8907\u884c\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u78bc\uff1a<\/p>\n

WITH CTE AS (\n    SELECT *,\n           ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY (SELECT NULL)) AS rn\n    FROM your_table\n)\nDELETE FROM CTE WHERE rn > 1;<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0ccolumn1<\/code>\u548ccolumn2<\/code>\u662f\u7528\u4f86\u5224\u65b7\u91cd\u8907\u7684\u5217\uff0c\u60a8\u53ef\u4ee5\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u9032\u884c\u8abf\u6574\u3002<\/p>\n
\u65b9\u6cd5\u4e8c\uff1a\u4f7f\u7528GROUP BY\u548cHAVING\u5b50\u53e5<\/h2>\n
\u901a\u904eGROUP BY\u548cHAVING\u5b50\u53e5\uff0c\u53ef\u4ee5\u627e\u51fa\u91cd\u8907\u7684\u884c\uff0c\u7136\u5f8c\u522a\u9664\u5b83\u5011\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u78bc\uff1a<\/p>\n
DELETE FROM your_table\nWHERE ID NOT IN (\n    SELECT MIN(ID)\n    FROM your_table\n    GROUP BY column1, column2\n);<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u6703\u4fdd\u7559\u6bcf\u7d44\u91cd\u8907\u884c\u4e2d\u7684\u6700\u5c0fID\uff0c\u4e26\u522a\u9664\u5176\u4ed6\u91cd\u8907\u884c\u3002<\/p>\n
\u65b9\u6cd5\u4e09\uff1a\u4f7f\u7528DISTINCT\u548cINSERT INTO<\/h2>\n
\u9019\u7a2e\u65b9\u6cd5\u6d89\u53ca\u5230\u5275\u5efa\u4e00\u500b\u65b0\u8868\uff0c\u5c07\u4e0d\u91cd\u8907\u7684\u6578\u64da\u63d2\u5165\u5230\u65b0\u8868\u4e2d\uff0c\u7136\u5f8c\u518d\u5c07\u539f\u8868\u522a\u9664\u3002\u793a\u4f8b\u4ee3\u78bc\u5982\u4e0b\uff1a<\/p>\n
SELECT DISTINCT *\nINTO new_table\nFROM your_table;\n\nDROP TABLE your_table;\n\nEXEC sp_rename 'new_table', 'your_table';<\/code><\/pre>\n
\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u539f\u8868\u4e2d\u53ea\u4fdd\u7559\u552f\u4e00\u7684\u884c\u3002<\/p>\n
\u65b9\u6cd5\u56db\uff1a\u4f7f\u7528TEMP TABLE<\/h2>\n
\u60a8\u4e5f\u53ef\u4ee5\u4f7f\u7528\u81e8\u6642\u8868\u4f86\u522a\u9664\u91cd\u8907\u884c\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u78bc\uff1a<\/p>\n
SELECT DISTINCT *\nINTO #temp_table\nFROM your_table;\n\nDELETE FROM your_table;\n\nINSERT INTO your_table\nSELECT * FROM #temp_table;\n\nDROP TABLE #temp_table;<\/code><\/pre>\n
\u9019\u7a2e\u65b9\u6cd5\u7684\u512a\u9ede\u662f\u53ef\u4ee5\u5728\u522a\u9664\u4e4b\u524d\u6aa2\u67e5\u81e8\u6642\u8868\u4e2d\u7684\u6578\u64da\u3002<\/p>\n
\u65b9\u6cd5\u4e94\uff1a\u4f7f\u7528EXISTS\u5b50\u53e5<\/h2>\n
EXISTS\u5b50\u53e5\u53ef\u4ee5\u7528\u4f86\u6aa2\u67e5\u91cd\u8907\u884c\uff0c\u7136\u5f8c\u9032\u884c\u522a\u9664\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u78bc\uff1a<\/p>\n
DELETE FROM your_table\nWHERE EXISTS (\n    SELECT 1\n    FROM your_table AS t2\n    WHERE t2.column1 = your_table.column1\n      AND t2.column2 = your_table.column2\n      AND t2.ID < your_table.ID\n);<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u6703\u522a\u9664\u6240\u6709\u91cd\u8907\u7684\u884c\uff0c\u53ea\u4fdd\u7559\u6bcf\u7d44\u91cd\u8907\u884c\u4e2d\u7684\u4e00\u500b\u3002<\/p>\n
\u65b9\u6cd5\u516d\uff1a\u4f7f\u7528\u81ea\u9023\u63a5<\/h2>\n
\u81ea\u9023\u63a5\u662f\u4e00\u7a2e\u901a\u904e\u5c07\u8868\u8207\u81ea\u8eab\u9032\u884c\u9023\u63a5\u4f86\u67e5\u627e\u91cd\u8907\u884c\u7684\u65b9\u6cd5\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\u4ee3\u78bc\uff1a<\/p>\n
DELETE t1\nFROM your_table t1\nINNER JOIN your_table t2\nON t1.column1 = t2.column1\nAND t1.column2 = t2.column2\nAND t1.ID > t2.ID;<\/code><\/pre>\n
\u9019\u6a23\u53ef\u4ee5\u522a\u9664\u6240\u6709\u91cd\u8907\u7684\u884c\uff0c\u53ea\u4fdd\u7559ID\u8f03\u5c0f\u7684\u884c\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728SQL Server\u4e2d\uff0c\u522a\u9664\u91cd\u8907\u884c\u7684\u65b9\u6cd5\u6709\u5f88\u591a\uff0c\u9078\u64c7\u5408\u9069\u7684\u65b9\u6cd5\u53ef\u4ee5\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u6578\u64da\u7684\u6e96\u78ba\u6027\u3002\u7121\u8ad6\u662f\u4f7f\u7528ROW_NUMBER()\u51fd\u6578\u3001GROUP BY\u3001DISTINCT\u3001TEMP TABLE\u3001EXISTS\u5b50\u53e5\u9084\u662f\u81ea\u9023\u63a5\uff0c\u9019\u4e9b\u65b9\u6cd5\u90fd\u80fd\u6709\u6548\u5730\u5e6b\u52a9\u60a8\u7ba1\u7406\u6578\u64da\u3002<\/p>\n
\u5982\u679c\u60a8\u9700\u8981\u66f4\u9ad8\u6548\u7684\u6578\u64da\u7ba1\u7406\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528\u9999\u6e2fVPS<\/a>\u6216\u4e91\u670d\u52a1\u5668<\/a>\u4f86\u63d0\u5347\u60a8\u7684\u6578\u64da\u5eab\u6027\u80fd\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u5b89\u5168\u8207\u7a69\u5b9a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22\u516d\u7a2e\u6709\u6548\u7684SQL Server\u522a\u9664\u91cd\u8907\u884c\u7684\u65b9\u6cd5\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u552f\u4e00\u6027\u8207\u6e96\u78ba\u6027\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-168171","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168171","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=168171"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168171\/revisions"}],"predecessor-version":[{"id":168172,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168171\/revisions\/168172"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168171"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168171"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168171"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}