sql distinct

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---沒有去除重復的記錄 select distinct ContractLaborEmployeeUidKey,ContractLaborEndDate from ContractLaborList order by ContractLaborEndDate desc       select  * from ContractLaborList order by ContractLaborEmployeeUidKey   ---沒有去除重復的記錄 select * from ContractLaborList where ContractLaborEmployeeUidKey in (select distinct ContractLaborEmployeeUidKey from ContractLaborList) order by ContractLaborEndDate desc   --去除ContractLaborEmployeeUidKey重復的記錄 select * from ContractLaborList where ContractLaborEndDate in( SELECT MAX(ContractLaborEndDate) AS ContractLaborEndDate FROM ContractLaborList GROUP BY ContractLaborEmployeeUidKey) --重复行只查询一条 order by ContractLaborEndDate desc   ---去除ContractLaborEmployeeUidKey重復的記錄 select * from ContractLaborList e WHERE e.ContractLaborEndDate = (SELECT max(x.ContractLaborEndDate) FROM ContractLaborList x WHERE x.ContractLaborEmployeeUidKey = e.ContractLaborEmployeeUidKey);   SELECT * FROM View_ContractLaborList   --取出ContractLaborEmployeeUidKey重復的值 SELECT  * FROM ContractLaborList s2 WHERE 1 < (SELECT COUNT(*)  FROM ContractLaborList s1 WHERE s1.ContractLaborEmployeeUidKey = s2.ContractLaborEmployeeUidKey)