步步為營-89-SQL語句(重複資料刪除資料)

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1:重複資料刪除資料

--第一步:先找到重複資料select ProcInstID from record_errorloggroup by ProcInstIDhaving count(ProcInstID) > 1--查看一下select * from record_errorlog where ProcInstID in (select ProcInstID from record_errorloggroup by ProcInstIDhaving count(ProcInstID) > 1);--第二部 保留ErrorLogID最大的(也就是最新的資料)delete  from record_errorlog where ProcInstID in (select ProcInstID from record_errorlog group by ProcInstID having count(ProcInstID) > 1)and ErrorLogID not in (select max(ErrorLogID) from  record_errorlog group by ProcInstID having count(ProcInstID )>1);

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步步為營-89-SQL語句(重複資料刪除資料)