select isnull(dm,null),isnull(t101,null),isnull(t102,null),isnull(t1flag,null),isnull(t201,null),isnull(t202,null),isnull(t2flag,null) from t1,t2 where t1.t1flag=1 and t2.t2flag=1
3楼漏了where,left应改为full, 应该是: select t1.dm,t1.t101,t1.t102,t1.t1flag,t2.t201,t2.t202,t2.t2flag from t1 full join t2 on t1.dm=t2.dm where t1.t1flag=1 or t2.t2flag=1
SELECT t1.dm,t101,t102,t1flag,t201, t202,t2flag FROM t1 left join t2 on t1.dm=t2.dm WHERE t1.t1flag=1UNIONSELECT t2.dm,t101,t102,t1flag,t201, t202,t2flag FROM t2 left join t1 on t1.dm=t2.dm WHERE t2.t2flag=1
SELECT t1.dm,t1.t101,t1.t102,t1.t1flag,t2.dm,t2.t201,t2.t202,t2.t2flag from t1 full join t2 on t2.dm = t1.dm where (t1.t1flag = 1 or t2.t2flag =1)
select t1.dm,t1.t101,t1.t102,t1.t1flag,t2.t201,t2.t202,t2.t2flag from t1 full join t2 on t1.dm=t2.dm where t1.t1flag=1 or t2.t2flag=1这样就可以了
应该是:
select t1.dm,t1.t101,t1.t102,t1.t1flag,t2.t201,t2.t202,t2.t2flag from t1
full join t2 on t1.dm=t2.dm
where t1.t1flag=1 or t2.t2flag=1
呵呵,问一下 两个表用什么字段关联?DM么?
所用数据库是sql server还是其他的?
t1.dm,t101,t102,t1flag,t201, t202,t2flag
FROM t1 left join t2 on t1.dm=t2.dm
WHERE t1.t1flag=1UNIONSELECT
t2.dm,t101,t102,t1flag,t201, t202,t2flag
FROM t2 left join t1 on t1.dm=t2.dm
WHERE t2.t2flag=1
from t1 full join t2
on t2.dm = t1.dm
where (t1.t1flag = 1
or t2.t2flag =1)
full join t2 on t1.dm=t2.dm
where t1.t1flag=1 or t2.t2flag=1这样就可以了