用子查询 select phone,grade,name from ( select count(*) as c ,phone,grade,name from table1 group by phone,grade,name) as f where c>1
select y1.phone,x1.grade,x1.name from x as x1,y as y1 where (select count(*) from x as x2,y as y2 where y1.phone=y2.phone and x1.grade=x2.grade and x1.name=x2.name)>0
select phone,grade,name from
(
select count(*) as c ,phone,grade,name from table1 group by phone,grade,name)
as f where c>1
x as x2,y as y2 where y1.phone=y2.phone and x1.grade=x2.grade and x1.name=x2.name)>0