两个表连接查询
a表
id 金额 科目编号
1 100 1001
2 200 1001

b表
id 金额 科目编号
3 100 1001
4 300 1001
5 450 1001
结果要
a金额 科目编号 b金额
100 1001 100
200 1001 300
0 1001 450

[解决办法]

drop table a,b
go

create table a(id int, 金额 int,科目编号 int)

insert into a
select 1  ,100,  1001 union all
select 2  ,200,  1001

create table b(id int, 金额 int, 科目编号 int)

insert into b
select 3  ,100,  1001 union all
select 4  ,300,  1001 union all
select 5  ,450,  1001
go

select isnull(a.金额,0) as 金额,b.科目编号,b.金额
from 
(
select *,
       ROW_NUMBER() over(order by id) rownum
from b
)b
left join a
       on a.科目编号 = b.科目编号 and
          a.id = b.rownum
/*
金额科目编号金额
1001001100
2001001300
01001450
*/       

Select 
  ISNull(t2.金额 ,0) a金额
  ,ISnull(t1.科目编号,t2.科目编号) 科目编号
  ,ISNull(t1.金额 ,0) b金额 
From 
(
  Select * From (row_number() Over (Order By B.id Asc)BRowNum 
  FROM B )t1
FULL JOIN 
(
select *, (row_number() Over (Order By A.id Asc) ARowNum
From A
)t2
On t1.BRowNum = t2.ARowNum