SQL Server 2008 R2 - 發現選擇語句之間的差異

Question

我如何找到基於同一個表的兩個選擇語句之間的差異？例如：基於上面的select語句

SELECT ID 
FROM Table as TableA 
WHERE Date = '2016-04-30' 

，我想找到的是不存在的所有ID：

SELECT ID 
FROM Table as TableB 
WHERE Date = '2016-03-31' 

Answer 1

較早的答案是一個聰明的一個。這是一個簡單的方法。

Select ID from Table 
where Date = '2016-04-30' 
and ID not in (select ID from Table where Date = '2016-03-31') 

Answer 2

SELECT ID 
FROM Table 
group by ID 
having sum(case when Date = '2016-04-30' then 1 else 0 end) > 0 
    and sum(case when Date = '2016-03-31' then 1 else 0 end) = 0