撈很久居然是因為在變數裡用funtion

select *
from 
	CUST t2 with (nolock) 
and BirthDate between dbo.YYYYMMDDtoCYMMDD (convert(varchar, getdate(), 112))-5 and dbo.YYYYMMDDtoCYMMDD (convert(varchar, getdate(), 112))

#這樣就解決了

declare @msDate int 
declare @meDate int 
set @msDate = dbo.YYYYMMDDtoCYMMDD (convert(varchar, getdate(), 112))-5
set @meDate = dbo.YYYYMMDDtoCYMMDD (convert(varchar, getdate(), 112))

select * 
from 
	CUST t2 with (nolock) 
where BirthDate between  @msDate and  @meDate 

如果上面的方式還是不行,可以再試試用
EXEC('select ....')