select a.field1,a.field2,b.field3 from 表1 as a left join 表2 as b on b.field1=a.field1刚学delphi,但SQL语句还是可以的。
select a.field1,isnull(a.field2,0),isnull(b.field3,0) from 表1 as a left join 表2 as b on b.field1=a.field1 union select a.field1,isnull(b.field2,0),isnull(a.field3,0) from 表2 as a left join 表1 as b on b.field1=a.field1行了,晕,不用MS SQL调试一下都不知。
select field1,sum(field2) as field2,sum(field3) as field3 from (select field1,field2,0 as field3 from 表1 union select field1,0,field3 from 表2 ) as a group by field1
left join 表2 as b on b.field1=a.field1刚学delphi,但SQL语句还是可以的。
union
select a.field1,isnull(b.field2,0),isnull(a.field3,0) from 表2 as a left join 表1 as b on b.field1=a.field1行了,晕,不用MS SQL调试一下都不知。
from
(select field1,field2,0 as field3
from 表1
union
select field1,0,field3
from 表2
) as a
group by field1