我有一个像下面的查询:减法 - 嵌套查询SQL
select ISNULL(sum(fonhand),0.00) as 'Supply', 0 as 'Demand'
from invoice where ptno = @ptno
union
select distinct a.quantity as 'Supply', 0 as 'Demand'
from jbMstr a join jbDetails b on a.fjobno = b.fjobno
where a.ptno = @ptno AND a.status = 'RELEASED' AND fbmsource = 'S'
union
select 0 as 'Supply', ftotqty as 'Demand'
from jbDetails a join jbMstr b on a.fjobno = b.fjobno
where fbompart = @ptno and fstatus = 'RELEASED' AND fbmsource = 'S'
输出像以下:
Supply Demand Avail
-4.00000 0.0000000000 -4
0.00000 1.0000000000 -5
0.00000 1.0000000000 -6
0.00000 4.0000000000 -10
0.00000 -1.0000000000 -9
在这里,我想获得新的栏目“库存状况”,它应该从每行的“需求”栏中减去。如何实现这一点?
任何人都可以帮助我做到这一点? 在此先感谢...
标记使用的dbms。 (ISNULL()是特定于产品的功能。) – jarlh
由于UNION删除所有重复项,因此无需执行SELECT DISTINCT。 – jarlh