Relation = Table or File Attribute = Column or Field Entity = Tuple, Record or Row
-- Simon Oliver "Vuillemot, Ward W" wrote: > > Basically that is what I thought. > > However, please define "relation". Do you mean table? > > -----Original Message----- > From: Simon Oliver [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, October 23, 2001 7:06 AM > To: '[EMAIL PROTECTED]' > Subject: Re: multiple primary keys > > Each relation should have one primary key: the set of columns that > identifies unique entities. The set of columns may contain between 1 > and n columns, where n is the number of columns in the relation. > > Some database design applications allow alternate primary keys. In real > life these are usually defined by creating unique indexes. > > -- > Simon Oliver
