It depends a lot on what db you are using. My DB (Openbase) knows how to handle this:
Select Name from Person Where (Select Count(*) From Link Where Link.pid=Personen.id)>1 Max -> Maximilian Tyrtania | [EMAIL PROTECTED] fischerAppelt Kommunikation GmbH Tucholskystr. 18 | D-10117 Berlin | Germany Tel. ++49-30-726146-728 | Fax ++49-30-726146-710 www.fischerAppelt.de _______________________________________________________________ +++mamamoto, die Initiative von Ligalux für ein neues Familienbild, ist am 10. März in Hamburg gestartet. Damit Familie wieder sichtbar Spaß macht http://www.mamamoto.de +++ -- > Hello all, > > I hope some of you SQL wizards can help me figure this out: > > The statement below works perfectly. I get all student names in the > class with a class id of "A" > SELECT person.name FROM person, class, link WHERE link.pid=person.id > AND link.cid=class.id AND class.id="A" > > What I can't figure out is how to get the names of students who are in > TWO or more classes, "A" and "B", for example. In English: "Select > all students who are in class A as well as class B". Or any > combination of multiple classes: A&C, A,B&C, etc. Can that be > accomplished in one select statement? I haven't been able to do that. > > db setup: > > Table: person > Columns: id, Name > > Table: class > Columns: id, Name > > Table: link > Columns: pid, cid > > Thanks for any guidance. I'm really stumped. > > -- > Sean McCollum > Mac OS 10.4.7 > RB 2006 r3 Pro > _______________________________________________ > Unsubscribe or switch delivery mode: > <http://www.realsoftware.com/support/listmanager/> > > Search the archives of this list here: > <http://support.realsoftware.com/listarchives/lists.html> _______________________________________________ Unsubscribe or switch delivery mode: <http://www.realsoftware.com/support/listmanager/> Search the archives of this list here: <http://support.realsoftware.com/listarchives/lists.html>
