根据派生列检索数据

Question

如何将以下代码重写为sql.我需要根据我的新'item'

从另一个表中检索'newcol'

代码是。

select 
  s.code,
  o.[work name],
  case when o.[work name] is null 
    then s.code 
    else o.[work name] 
  end newcol,
  item=(select item from table1 where table1.code=newcol)
from 
  shoplog s 
  left outer join odc o on o.barcode=s.code

Answer 1

您可以使用sub-query来实现您的需求。

 select a.code, a.[work name], a.newcol, b.code  as item
  from
  (select
   s.code,
  o.[work name],
  case when o.[work name] is null 
  then s.code 
  else o.[work name] 
  end newcol
  from 
  #shoplog s 
  left outer join #odc o on o.barcode=s.code
  )a
  inner join 
  #table1 b
  on (a.newcol = b.code)