How to check if value exists in each group (after group by)

Question

Assume I have a subscriptions table :

uid  | subscription_type 
------------------------  
Alex | type1
Alex | type2
Alex | type3
Alex | type4
Ben  | type2
B         


        

Answer 1

Create Sample Table:

CREATE TABLE subscribes
(
uid NVARCHAR(MAX),
subscription_type NVARCHAR(MAX)
)

Insert Values:

INSERT INTO subscribes
VALUES ('Alex', 'type1'), ('Alex', 'type2'), ('Alex', 'type3'), ('Alex', 'type4'),  ('Ben', 'type2'), ('Ben', 'type3'), ('Ben', 'type4')

SQL Query:

SELECT uid
FROM subscribes
GROUP BY uid
HAVING COUNT(*) > 2
AND MAX(CASE subscription_type WHEN 'type1' THEN 1 ELSE 0 END) = 0

Output:

======
|uid |
------
|Ben |
======

Answer 2

To check if something doesn't exist, use NOT EXISTS(...):

SELECT uid
FROM subscribes su
WHERE NOT EXISTS (SELECT *
        FROM subscribes nx
        WHERE nx.uid = su.uid AND nx.subscription_type = 'type1'
        )
GROUP BY uid HAVING COUNT(*) > 2
        ;

Answer 3

Try this query:

SELECT uid 
FROM subscribes 
GROUP BY uid 
HAVING COUNT(*) > 2
   AND max( CASE "subscription_type"  WHEN 'type1' THEN 1 ELSE 0 END ) = 0