Question

我有一个冗长的oracle SQL脚本，它使用了几个子查询。有没有办法可以避免重复子查询脚本，如果我想使用相同的子查询作为另一个计算的一部分，例如在下面这么小的剧本中，我可以给出＆＃39; onhand_uk＆＃39;子查询别名所以我只能在＆＃39; running_stock_UK＆＃39;中使用别名。子查询？

select distinct 
    trunc(al.date_required) date_allocated, 
    al.component_part, al.qty_required, 
    sum(al.qty_required) over (partition by al.component_part order by trunc(al.date_required), al.component_part) running_demand_UK,
    (select sum(pl.qty_onhand) 
     from part_loc pl 
     where al.component_part = pl.part_no and pl.plant in ('W','2') and pl.location_type = 'IN') onhand_UK,
    (select sum(pl.qty_onhand) 
     from part_loc pl 
     where al.component_part = pl.part_no and pl.plant in ('W','2') and pl.location_type = 'IN') - sum(al.qty_required) over (partition by al.component_part order by trunc(al.date_required), 
    al.component_part) running_stock_UK
from 
    allocations al, part_description pd
where 
    al.alloc_plant = 'W'
    and al.status_code between '4' and '8'
    and al.component_part like 'Y%'
    and al.component_part = 'Y450569'
    and al.component_part = pd.part_no
    and substr(pd.prodtyp,1,2) in ('JC','KT','TR')  
order by 
    al.component_part, trunc(al.date_required)

非常感谢你的帮助。

Answer 1

就像Dan Bracuk一样，我虽然你也在寻找WITH statement，但我已经看过你的查询了，在这种情况下我只想把所有东西都移到子查询中，然后拉出减法主查询：

select
  x.date_allocated,
  x.component_part,
  x.qty_required,
  x.running_demand_UK,
  x.onhand_UK,
  x.running_demand_UK - x.onhand_UK as running_stock_UK
from
    (select distinct 

      trunc(al.date_required) date_allocated, 
      al.component_part, al.qty_required, 

      sum(al.qty_required) over (
            partition by al.component_part 
            order by trunc(al.date_required), al.component_part) running_demand_UK,

      (select sum(pl.qty_onhand) from part_loc pl 
       where al.component_part = pl.part_no 
            and pl.plant in ('W','2') 
            and pl.location_type = 'IN') onhand_UK

    from allocations al, part_description pd

    where al.alloc_plant = 'W'
        and al.status_code between '4' and '8'
        and al.component_part like 'Y%'
        and al.component_part = 'Y450569'
        and al.component_part = pd.part_no
        and substr(pd.prodtyp,1,2) in ('JC','KT','TR') ) x
order by 
  x.component_part, 
  x.date_allocated

我可以为子查询创建别名，以便我可以在其他子查询中使用别名吗？

1 个答案: