查看同一組中的所有記錄是否爲可接受的類型

Question

請考慮下表。每個文檔（id）都屬於一個組（group_id）。

----------------------- 
id group_id value 
----------------------- 
1  1   A 
2  1   B 
3  1   D 
4  2   A 
5  2   B 
6  3   C 
7  4   A 
8  4   B 
9  4   B 
10  4   B 
11  4   C 
12  5   A 
13  5   A 
14  5   A 
15  6   B 
16  6   NULL 
17  6   NULL 
18  6   D 
19  7   NULL 
20  8   B 

1 /每個文檔具有值NULL，A，B，C或D

2 /如果在同一組中的文件的所有要麼A或B作爲值，該組被完成

3 /在這種情況下，所期望的輸出將是：

--------------------- 
group_id completed 
--------------------- 
    1   0  <== because document 3 = D 
    2   1  <== all documents have either A or B as a value 
    3   0  <== only one document in the group, value C 
    4   1  <== all documents have either A or B as a value 
    5   1  <== all documents have value A 
    6   0  <== because of NULL values and value D 
    7   0  <== NULL 
    8   1  <== only one document, value B 

是否有可能查詢此結果集？

因爲我不是很有經驗的SQL，任何幫助將不勝感激！

Answer 1

嘗試此

SELECT [group_id], 
     CASE 
     WHEN Count(CASE WHEN [value] IN ('A', 'B') THEN 1 END) = Count(*) THEN 1 
     ELSE 0 
     END AS COMPLETED 
FROM yourtable 
GROUP BY [group_id]