Table: group_member

Records the members that have joined each group

gid i fk: group.gid: The gid (group id) for the relationship
member_type: A non-selectable wrapper used for each item in the positions list
positions: A list of positions the member holds within the group. Valid values are {OWNER, MEMBER, ADMIN, OFFICER, NOT_REPLIED}
uid i fk: user.uid: The uid (user id) for the relationship