C++博客-Error-随笔分类-SQLhttp://www.cppblog.com/Error/category/21233.htmlzh-cnTue, 20 Dec 2016 22:22:34 GMTTue, 20 Dec 2016 22:22:34 GMT60sql删除重复数据http://www.cppblog.com/Error/archive/2016/12/19/214520.htmlEnicEnicMon, 19 Dec 2016 05:58:00 GMThttp://www.cppblog.com/Error/archive/2016/12/19/214520.htmlhttp://www.cppblog.com/Error/comments/214520.htmlhttp://www.cppblog.com/Error/archive/2016/12/19/214520.html#Feedback0http://www.cppblog.com/Error/comments/commentRss/214520.htmlhttp://www.cppblog.com/Error/services/trackbacks/214520.html
select * into [QPTreasureDB].dbo.[WinLoseScoreInfo2] from [QPTreasureDB].dbo.[WinLoseScoreInfo]
drop table [WinLoseScoreInfo]
select distinct * into [QPTreasureDB].dbo.[WinLoseScoreInfo] from [WinLoseScoreInfo2]

2.如果表中有id字段可以考虑：先根据指定字段查询重复数据，然后根据不为已的id设置保留数据
select UserId, ServerId, DateId, count(*) as [count], @@rowid--, ROW_NUMBER()over(order by UserId, ServerId, DateId) 
from QPTreasureDB.dbo.WinLoseScoreInfo 
group by UserId, ServerId, DateId 
having count(*) > 1;


Enic 2016-12-19 13:58 发表评论
]]>SQL各种连接备忘http://www.cppblog.com/Error/archive/2016/07/11/213912.htmlEnicEnicMon, 11 Jul 2016 02:09:00 GMThttp://www.cppblog.com/Error/archive/2016/07/11/213912.htmlhttp://www.cppblog.com/Error/comments/213912.htmlhttp://www.cppblog.com/Error/archive/2016/07/11/213912.html#Feedback0http://www.cppblog.com/Error/comments/commentRss/213912.htmlhttp://www.cppblog.com/Error/services/trackbacks/213912.htmlINNER JOIN  交集
FULL JOIN(OUTER JOIN) 并集（left right都可能匹配成null）
LEFT JOIN  （right可能匹配null）
RIGHT JOIN  （left可能匹配null）
CROSS JOIN  笛卡尔
UNION ALL  多表查询结果合并
UNION  多表查询结果合并去重


Enic 2016-07-11 10:09 发表评论
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