使用NOT IN：

SELECT DISTINCT
    name
FROM
    table
WHERE
    attribute = 'data3'
    AND
    name NOT IN (SELECT name FROM table WHERE attribute != 'data3')
;

或使用EXCEPT：

SELECT name FROM table WHERE attribute  = 'data3'
EXCEPT
SELECT name FROM table WHERE attribute != 'data3'
;

select   name
from     t
group by name
having   max(attribute) = 'data3'
and      max(attribute) = min(attribute)

名称

Item4
Item5
Fiddle