sql - 使用 select 语句作为列之一

Question

我有一个查询：

select 
      index_imsid
    , SUM(weighted_value) sumWeightedValue
    , (
        select 
              top 1 percentof
            , [Plan_Name_OR_Payment_Type] 
        from [v_PlanPerProvider1] 
        where [PLAN_RANK]=1
      ) plan1
from [v_PlanPerProvider1]
where plan_rank between 1 and 10
group by index_imsid
order by 1

我收到了这个错误：

Msg 116, Level 16, State 1, Line 3
当子查询没有用 EXISTS 引入时，只能在选择列表中指定一个表达式。

你能帮我理解为什么我会收到这个错误吗？

看来它不喜欢将 select 语句作为列之一？

Answer 1

它不喜欢您在子查询中选择两列。您一次只能选择一列。

  select index_imsid, SUM(weighted_value) sumWeightedValue,
    (select top 1 percentof from [v_PlanPerProvider1] where [PLAN_RANK]=1) percentof
    (select top 1 [Plan_Name_OR_Payment_Type] from [v_PlanPerProvider1] where [PLAN_RANK]=1) Plan_Name_OR_Payment_Type
  from [v_PlanPerProvider1]
  where plan_rank between 1 and 10
  group by index_imsid
  order by 1

Answer 2

或者你可以这样做：

select  
    t1.index_imsid, SUM(t1.weighted_value) sumWeightedValue, t2.percentof, t2.[Plan_Name_OR_Payment_Type]
from [v_PlanPerProvider1] t1
cross join (select top 1 percentof, [Plan_Name_OR_Payment_Type] from [v_PlanPerProvider1] where [PLAN_RANK]=1) t2 
where t1.plan_rank between 1 and 10 
group by t1.index_imsid, t2.percentof, t2.[Plan_Name_OR_Payment_Type]
order by 1