Help with a mysql query

Question

I'm sorry for the specificity of this question, but i've been up for 48h and my mind is probably void right now.

so, I have a table -> id|userid|card
where a user can have multiple cards

I just need to query the table to find the userid that have exactly 24 distinct cards (there are users with repeated cards).

Can someone help me please?

Thank you

Answer 1

SELECT UserID
FROM tableName
GROUP BY UserID
HAVING COUNT(*) = 24

See GROUP BY (Aggregate) Functions

Update: to find users that have 24 distinct cards:

SELECT UserID
FROM (
    SELECT UserID
    FROM tableName
    GROUP BY UserID, Card
) rs
GROUP BY UserID
HAVING COUNT(*) = 24

Alternatively:

SELECT UserID
FROM tableName
GROUP BY UserID
HAVING COUNT(DISTINCT Card) = 24

Answer 2

SELECT userid FROM (
    SELECT userid, count(*) as cnt FROM some_table GROUP BY userid
) WHERE cnt = 24