MySQL删除重复数据保留一条，该怎么办？

1、查找表中的多余的重复记录，重复记录是根据单个字段（empID）来判断

select * from Employee where EmpID in (select EmpID from Employee group by  EmpID  having count(EmpID)>1 )

2、删除表中多余的重复记录，重复记录是根据单个字段（empID）来判断，，

select * from Employee where EmpID in (select EmpID from Employee group by  EmpID  having count(EmpID)>1 )

多字段：

1、选择：

select * from  vitae emp where (emp.empID,emp.seq) in (select empID,seq from vitae group by empID ,seq having count(*) >1)

2、删除

delete from employee where empName in(select empName from employee group by empName having count(empName)>1) and empID not in (select min(empID) from employee group by empName having count(empName)>1 )