查询检索所有相关的值都为空组

Question

我有以下几点：

| Group_ID | Value | 
|----------|-------| 
|  146 | A | 
|  146 | B | 
|  239 | NULL | 
|  239 | F | 
|  826 | NULL | 
|  826 | NULL | 

我需要检索仅具有所有相关的值无效的ID。 在这个例子中，输出将是​​。

我知道这似乎是一个简单的查询，但我很长时间以来一直在努力。

Answer 1

select group_id 
from t 
group by group_id having sum(case when value is null then 1 end)=count(*) 

Answer 2

这应做到：

select t1.group_id 
from foo t1 
group by t1.group_id 
having count(*) = (select count(*) 
        from foo t2 
        where t2.group_id = t1.group_id 
        and t2.value is null); 

SQLFiddle例如：http://sqlfiddle.com/#!15/7d228/1

Answer 3

SELECT DISTINCT Group_ID 
FROM Your_Table a 
WHERE Value IS NULL 
    AND NOT EXISTS (
        SELECT NULL 
        FROM  Your_Table b 
        WHERE Value IS NOT NULL 
         AND b.Group_ID = a.Group_ID 
        ) 

Answer 4

试试这个：

select distinct Group_id 
from test 
where value is null 
    and Group_id not in (select Group_id from test where value is not null)