只筛选一个字段值相同的记录

select * from A where PDDT in( select PDDT FROM A group by PDDT having count(PDDT)>1)

筛选多个字段值相同的的记录

SELECT COUNT(*),DeptID, PDDT , DLNo , DLNoRe, MacNo FROM A GROUP BY DeptID, PDDT , DLNo , DLNoRe, MacNo having count(*)>1