可以使用聚合：

select id
from t
group by id
having min(type) = max(type) and min(type) = 'Web';

我们可以在这里使用exists逻辑：

SELECT DISTINCT ID
FROM yourTable t1
WHERE
    t1.Type = 'Web' AND
    NOT EXISTS (SELECT 1 FROM yourTable t2
                WHERE t2.ID = t1.ID AND t2.Type <> 'Web');

演示

你可以试着用 not exists 演示

select distinct id, type from tablename t1
    where not exists
      ( select 1 from tablename t2 where t1.id=t2.id and t2.type<>'Web')

你可以用 SELECT id, count(*) as total FROM table_name WHERE type = 'Web' GROUP BY type HAVING total = 1)

试着像下面我刚刚编辑了你的答案添加了一个where子句

SELECT id FROM tbl t1
  where 
  t1.id in ( select id from tbl a where a.type='Web')
 GROUP BY id
 HAVING COUNT(DISTINCT type) = 1