Searching many-to-many map tables

Hello, I am trying to find out how to search a many-to-many map table efficiently. I have an example table: user,user_group 1,1 1,2 2,1 3,2 I want to find out all the users who are a member of BOTH groups 1 AND 2. In this example, this would just be the user with id 1. Until now, I can either do this with multiple queries and using PHP array_intersect, or one really ugly MySQL query: select user, count(user_group) as num_groups_found from users_groups where group IN (1,2) GROUP BY user HAVING num_groups_found=2 i.e. narrows down the groups I'm looking for and makes sure that they are all found for a user It works quite reliably I think but it's such a rubbish query that I was hoping that somebody could teach me some syntax that is better. Many thanks in advance, Steve