比如:
temp1 表ks dw km
01 1001 1201
01 1001 1202
02 1001 1201现在要取出 ks,dw,km字段但是要保证dw km唯一性
也就是取出
01 1001 1201
01 1001 1202
或者
01 1001 1202
02 1001 1201ks字段取01或02都可以,不做要求。我用下面这句取出来却是
select b.ks,a.dw,a.km from
(select dw,km from temp1 group by dw,km) a left join
(select ks,dw,km from temp1 group by ks,dw,km) b
on a.dw=b.dw and a.km=b.km ks dw km
---------- ---------- ----------
01 1001 1201
02 1001 1201
01 1001 1202
temp1 表ks dw km
01 1001 1201
01 1001 1202
02 1001 1201现在要取出 ks,dw,km字段但是要保证dw km唯一性
也就是取出
01 1001 1201
01 1001 1202
或者
01 1001 1202
02 1001 1201ks字段取01或02都可以,不做要求。我用下面这句取出来却是
select b.ks,a.dw,a.km from
(select dw,km from temp1 group by dw,km) a left join
(select ks,dw,km from temp1 group by ks,dw,km) b
on a.dw=b.dw and a.km=b.km ks dw km
---------- ---------- ----------
01 1001 1201
02 1001 1201
01 1001 1202
select a.dw,a.km,(select ks from temp1 where dw=a.dw and km=a.km)
from (select distinct dw,km from temp1) a
select max(rowid) from temp1 t2 where t1.dw=t2.dw and t1.km=t2.km)