Hi !'ve been wondering how to formulate a query to get a set of objects out of a database, and am a bit stuck. I hope that someone here might be able to help. This is what the db looks like: Table TYPES id int primary key, description text Table GROUPS id int primary key description text Tables WIDGETS type_id int references TYPES(id), group_id int references GROUPS(id), primary key(type_id, group_id) Now, given two type_id's, say A and B, I would like to find all groups (or group_id's of course) that have a widget of both of these two types. Can anyone help with this please? Thanks! ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly