A表
A1 A2 A3 A4 A5
1 AA 11 23 34
2 BB 22 45 67
3 AA 11 45 56
5 BB 22 23 34
6 AA 11 45 67
7 BB 22 45 56要求A2 和A3相同的记录,,并取唯一值,并按倒序...结果:
6 AA 11 45 67
7 BB 22 45 56
A1 A2 A3 A4 A5
1 AA 11 23 34
2 BB 22 45 67
3 AA 11 45 56
5 BB 22 23 34
6 AA 11 45 67
7 BB 22 45 56要求A2 和A3相同的记录,,并取唯一值,并按倒序...结果:
6 AA 11 45 67
7 BB 22 45 56
where not exists(select * from tb
where a.A2=A2 and a.A3=A3 and A.A1<A1)
where not exists(select * from tb b
where a.A2=b.A2 and b.A3=a.A3 and (b.A4>a.A4
or (b.A4=a.A4 and b.A5>a.A5)))
select *
from tb t
where a1 = (select max(a1) from tb where a2 = t.a2 and a3 = t.a3)
where not exists(select * from tb b
where a.A2=b.A2 and b.A3=a.A3 and b.A1>a.A1)
where a.A2 = b.A2 and a.A3 = b.A3
order by A1 desc
*
from
tb t
where
a1 = (select max(a1) from tb where a2 = t.a2 and a3 = t.a3)