如何選擇不同的ID時，ID可能有多個值

Question

目的：找出所有屬性，所有的評級是不是A到d

問題：如果一個屬性有多個等級不屬於A - d那麼這些仍然算在內。

代碼：

Select DISTINCT (PropertyID) 
FROM TableA 
WHERE Rating NOT BETWEEN 'A' AND 'D' 

Answer 1

Select PropertyID 
FROM TableA 
group by PropertyID 
having sum(case when Rating IN ('A','B','C','D') then 1 else 0 end) = 0 

如果只想屬性的數量，然後把計數週圍

select count(*) as property_count 
from 
(
    select PropertyID from tableA ... 
) alias_name