嘗試在 WHERE 子句中創建 case 表達式（一個值等於多個）

Question

我希望能夠在WHERE子句中創建一個 case 表達式，該表達式將使用一個變量來確定要應用的標准：

declare @Classification VARCHAR(20)
set @Classification = 'Leaseup/Stabilized' 

select *
from attributes a
where 
    if @Classification = 'Leaseup/Stabilized' then a.subgroup8 in ('Lease-up Communities', 'Stabilized 
        Communities')
    if @Classification = 'Product Type' then a.subgroup6 in ('Freestanding AL/ALZ', 'Rental Continuums')

Answer 1

只需使用常規邏輯：

select a.*
from attributes a
where (@Classification = 'Leaseup/Stabilized' and a.subgroup8 in ('Lease-up Communities', 'Stabilized Communities'
      ) OR
      (@Classification = 'Product Type' and a.subgroup6 in ('Freestanding AL/ALZ', 'Rental Continuums')
      )

Answer 2

如果你真的想要Case在哪里

      declare @Classification 
       VARCHAR(20)
        set @Classification = 
       'Leaseup/Stabilized' 

   select *
     from attributes a
     where 
   1=  max (Case when @Classification = 
 'Leaseup/Stabilized' and a.subgroup8 in 
   ('Lease-up Communities', 'Stabilized 
    Communities') then 1 end) or
  1=   max (Case when @Classification = 
    'Product Type' and a.subgroup6 in 
    ('Freestanding AL/ALZ', 'Rental 
      Continuums') then 1 end)