SQL joins question

I want to link up 3 tables to list all members of a particular group. My
code (which is wrong) looks like this:

@group_members = Membership.find( :all,
:joins => ['FROM memberships INNER
JOIN groups ON memberships.group_id= group.id' + 'INNER JOIN users ON

this form of sql assumes that you are giving it a list of associaton
names, ie

Membership.find(:all, :joins => [:groups, :users]) looks like it would
do what you are trying to do.

The other form involves sql fragments, in which case you must provide
one such fragment, not an array ie

@group_members = Membership.find( :all,
                                   :joins => 'INNER JOIN groups ON
memberships.group_id= group.id INNER JOIN users ON