Netflix SQL Interview Question 09

Multi-Genre
Users

Find users who watched content from more than 2 distinct genres.

Schema

Table
Setup

Column Name	Type	Description
user_id	integer	User identifier.
content_id	integer	Watched content identifier.

Column Name	Type	Description
content_id	integer	Content identifier.
genre	varchar	Genre name.

Sample Data

Sample Input: watching_activity

Sample Input: content

Expected Output

user_id
101
104

SQL Editor

Waiting for query

user_id
101
104

Hints

Hint 01: The genre is in content.

Hint 02: Join on content_id.

Hint 03: Use HAVING COUNT(DISTINCT genre) > 2.

Solution

Solution is locked until you decide to reveal it. Try the editor first, then open this when you want the reference answer.

SELECT
  w.user_id
FROM watching_activity w
JOIN content c
  ON w.content_id = c.content_id
GROUP BY w.user_id
HAVING COUNT(DISTINCT c.genre) > 2;

Explanation

Join each watched content row to its genre.

Group the result by user_id.

Keep users with more than two distinct genres.