Question

I have user and user_role tables.

The user_role table has two columns:

user_id
role_name

I want to find users that have multiple roles at the same time, for example ‘admin‘ and ‘moderator‘.

How can I build this query?

Answer 1

You need two joins, one for filtering admins, and the other one for moderators:

SELECT user.*
FROM user
INNER JOIN user_role admins
ON admins.user_id = user.id
AND admins.role_name = 'admin'
INNER JOIN user_role mods
ON mods.user_id = user.id
AND mods.role_name = 'moderator'