{"id":138461,"date":"2024-10-31T14:40:19","date_gmt":"2024-10-31T06:40:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/138461\/"},"modified":"2024-10-31T14:40:20","modified_gmt":"2024-10-31T06:40:20","slug":"sql-server%e8%99%95%e7%90%86%e9%87%8d%e8%a4%87%e5%80%bc%e7%9a%84%e6%9c%89%e6%95%88%e6%96%b9%e6%b3%95%ef%bc%88sqlserver%e9%87%8d%e8%a4%87%e5%80%bc%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/138461\/","title":{"rendered":"SQL Server\u8655\u7406\u91cd\u8907\u503c\u7684\u6709\u6548\u65b9\u6cd5\uff08sqlserver\u91cd\u8907\u503c\uff09"},"content":{"rendered":"

SQL Server\u8655\u7406\u91cd\u8907\u503c\u7684\u6709\u6548\u65b9\u6cd5\uff08sqlserver\u91cd\u8907\u503c\uff09<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u91cd\u8907\u503c\u662f\u4e00\u500b\u5e38\u898b\u7684\u554f\u984c\uff0c\u7279\u5225\u662f\u5728\u4f7f\u7528SQL Server\u6642\u3002\u91cd\u8907\u503c\u4e0d\u50c5\u6703\u5f71\u97ff\u6578\u64da\u7684\u5b8c\u6574\u6027\uff0c\u9084\u53ef\u80fd\u5c0e\u81f4\u67e5\u8a62\u6027\u80fd\u4e0b\u964d\u3002\u56e0\u6b64\uff0c\u4e86\u89e3\u5982\u4f55\u6709\u6548\u5730\u8655\u7406\u91cd\u8907\u503c\u662f\u6bcf\u4f4d\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u5fc5\u9808\u638c\u63e1\u7684\u6280\u80fd\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u5728SQL Server\u4e2d\u8655\u7406\u91cd\u8907\u503c\u7684\u6709\u6548\u65b9\u6cd5\u3002<\/p>\n

1. \u4f7f\u7528GROUP BY\u548cHAVING\u5b50\u53e5<\/h2>\n

\u4e00\u7a2e\u5e38\u898b\u7684\u65b9\u6cd5\u662f\u4f7f\u7528GROUP BY<\/code>\u548cHAVING<\/code>\u5b50\u53e5\u4f86\u8b58\u5225\u91cd\u8907\u7684\u8a18\u9304\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u627e\u51fa\u54ea\u4e9b\u8a18\u9304\u662f\u91cd\u8907\u7684\uff0c\u4e26\u4e14\u53ef\u4ee5\u8a08\u7b97\u6bcf\u500b\u91cd\u8907\u503c\u7684\u51fa\u73fe\u6b21\u6578\u3002<\/p>\n

SELECT column1, column2, COUNT(*)\nFROM your_table\nGROUP BY column1, column2\nHAVING COUNT(*) > 1;<\/code><\/pre>\n
\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0cyour_table<\/code>\u662f\u6211\u5011\u8981\u67e5\u8a62\u7684\u8868\u683c\uff0ccolumn1<\/code>\u548ccolumn2<\/code>\u662f\u6211\u5011\u8981\u6aa2\u67e5\u91cd\u8907\u7684\u5217\u3002\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u91cd\u8907\u7684\u8a18\u9304\u53ca\u5176\u51fa\u73fe\u7684\u6b21\u6578\u3002<\/p>\n
2. \u4f7f\u7528CTE\uff08\u516c\u7528\u8868\u9054\u5f0f\uff09\u522a\u9664\u91cd\u8907\u503c<\/h2>\n
\u516c\u7528\u8868\u9054\u5f0f\uff08CTE\uff09\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u7528\u4f86\u522a\u9664\u91cd\u8907\u503c\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u4f7f\u7528CTE\u4f86\u522a\u9664\u91cd\u8907\u7684\u8a18\u9304\uff1a<\/p>\n
WITH CTE AS (\n    SELECT *,\n           ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY (SELECT NULL)) AS row_num\n    FROM your_table\n)\nDELETE FROM CTE WHERE row_num > 1;<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u4f7f\u7528ROW_NUMBER()<\/code>\u51fd\u6578\u70ba\u6bcf\u7d44\u91cd\u8907\u7684\u8a18\u9304\u5206\u914d\u4e00\u500b\u552f\u4e00\u7684\u884c\u865f\uff0c\u7136\u5f8c\u522a\u9664\u884c\u865f\u5927\u65bc1\u7684\u8a18\u9304\uff0c\u5f9e\u800c\u4fdd\u7559\u6bcf\u7d44\u7684\u7b2c\u4e00\u689d\u8a18\u9304\u3002<\/p>\n
3. \u4f7f\u7528DISTINCT\u95dc\u9375\u5b57<\/h2>\n
\u5982\u679c\u6211\u5011\u53ea\u60f3\u9078\u64c7\u552f\u4e00\u7684\u8a18\u9304\uff0c\u53ef\u4ee5\u4f7f\u7528DISTINCT<\/code>\u95dc\u9375\u5b57\u3002\u9019\u7a2e\u65b9\u6cd5\u4e0d\u6703\u522a\u9664\u91cd\u8907\u7684\u8a18\u9304\uff0c\u4f46\u53ef\u4ee5\u5728\u67e5\u8a62\u7d50\u679c\u4e2d\u6392\u9664\u5b83\u5011\u3002<\/p>\n
SELECT DISTINCT column1, column2\nFROM your_table;<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56deyour_table<\/code>\u4e2d\u6240\u6709\u552f\u4e00\u7684column1<\/code>\u548ccolumn2<\/code>\u7684\u7d44\u5408\u3002<\/p>\n
4. \u4f7f\u7528TEMP TABLE\u81e8\u6642\u8868<\/h2>\n
\u53e6\u4e00\u7a2e\u8655\u7406\u91cd\u8907\u503c\u7684\u65b9\u6cd5\u662f\u4f7f\u7528\u81e8\u6642\u8868\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u8b93\u6211\u5011\u5728\u522a\u9664\u91cd\u8907\u503c\u4e4b\u524d\u5148\u5c07\u552f\u4e00\u7684\u8a18\u9304\u5b58\u5132\u5230\u81e8\u6642\u8868\u4e2d\u3002<\/p>\n
SELECT DISTINCT *\nINTO #TempTable\nFROM your_table;\n\nDELETE FROM your_table;\n\nINSERT INTO your_table\nSELECT *\nFROM #TempTable;<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u9996\u5148\u5c07\u552f\u4e00\u7684\u8a18\u9304\u63d2\u5165\u5230\u81e8\u6642\u8868#TempTable<\/code>\u4e2d\uff0c\u7136\u5f8c\u6e05\u7a7a\u539f\u59cb\u8868\uff0c\u6700\u5f8c\u5c07\u552f\u4e00\u7684\u8a18\u9304\u91cd\u65b0\u63d2\u5165\u5230\u539f\u59cb\u8868\u4e2d\u3002<\/p>\n
5. \u4f7f\u7528\u7d22\u5f15\u9632\u6b62\u91cd\u8907\u503c<\/h2>\n
\u70ba\u4e86\u9632\u6b62\u672a\u4f86\u51fa\u73fe\u91cd\u8907\u503c\uff0c\u53ef\u4ee5\u5728\u8868\u4e2d\u5275\u5efa\u552f\u4e00\u7d22\u5f15\u3002\u9019\u6a23\uff0c\u7576\u5617\u8a66\u63d2\u5165\u91cd\u8907\u7684\u8a18\u9304\u6642\uff0cSQL Server\u5c07\u6703\u8fd4\u56de\u932f\u8aa4\u3002<\/p>\n
CREATE UNIQUE INDEX idx_unique_column\nON your_table (column1, column2);<\/code><\/pre>\n
\u9019\u6a23\u7684\u7d22\u5f15\u5c07\u78ba\u4fddcolumn1<\/code>\u548ccolumn2<\/code>\u7684\u7d44\u5408\u5728\u8868\u4e2d\u662f\u552f\u4e00\u7684\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728SQL Server\u4e2d\u8655\u7406\u91cd\u8907\u503c\u662f\u4e00\u9805\u91cd\u8981\u7684\u4efb\u52d9\uff0c\u7121\u8ad6\u662f\u901a\u904e\u4f7f\u7528GROUP BY<\/code>\u548cHAVING<\/code>\u5b50\u53e5\u3001CTE\u3001DISTINCT<\/code>\u95dc\u9375\u5b57\uff0c\u9084\u662f\u81e8\u6642\u8868\u548c\u552f\u4e00\u7d22\u5f15\uff0c\u9019\u4e9b\u65b9\u6cd5\u90fd\u80fd\u6709\u6548\u5730\u5e6b\u52a9\u6211\u5011\u7ba1\u7406\u6578\u64da\u7684\u5b8c\u6574\u6027\u3002\u4e86\u89e3\u9019\u4e9b\u6280\u8853\u4e0d\u50c5\u80fd\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u6027\u80fd\uff0c\u9084\u80fd\u78ba\u4fdd\u6578\u64da\u7684\u6e96\u78ba\u6027\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684VPS<\/a><\/code>\u89e3\u6c7a\u65b9\u6848\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u9069\u5408\u5404\u7a2e\u9700\u6c42\u3002\u7121\u8ad6\u662f\u9999\u6e2fVPS<\/a><\/code>\u9084\u662f\u5176\u4ed6\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22SQL Server\u4e2d\u8655\u7406\u91cd\u8907\u503c\u7684\u6709\u6548\u65b9\u6cd5\uff0c\u5b78\u7fd2\u5982\u4f55\u8b58\u5225\u3001\u522a\u9664\u548c\u7ba1\u7406\u91cd\u8907\u6578\u64da\u4ee5\u63d0\u5347\u6578\u64da\u8cea\u91cf\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-138461","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138461","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=138461"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138461\/revisions"}],"predecessor-version":[{"id":138462,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/138461\/revisions\/138462"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=138461"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=138461"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=138461"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}