search for: find_in_set

Hi, i was hoping someone could help me out with a small yet quite time-boggling task...i have a two tables users, groups joined in as a habtam relashinship (has and belongs to many) and i need to select from the mydb (mysql if it matters) users out of the User model, in accordance with TWO groups in one rails opperation to improve performance...basicly, say i have ten groups and ten users,