SQL Server查詢子查詢

Question

我有以下SQL

set @ID = '323232' 

select 
    tt.ItemOrder, tt.DisplayVal, 
    ActualDate = (select mfdate from mfseries where Id = @ID) 
from 
    tblTime tt 

有沒有一種方法來簡化這個查詢不使用子查詢？

Answer 1

DECLARE @date datetime 

select @date = mfdate from mfseries where Id = @ID 

select tt.ItemOrder,tt.DisplayVal,@date As ActualDate 
from tblTime tt