Path: utzoo!mnetor!uunet!husc6!mailrus!ames!ncar!noao!arizona!naucse!wew
From: wew@naucse.UUCP (Bill Wilson)
Newsgroups: comp.databases
Subject: Re: dBaseIII+
Message-ID: <640@naucse.UUCP>
Date: 18 Apr 88 17:24:50 GMT
References: <2413@mandrill.CWRU.Edu>
Organization: Northern Arizona University, Flagstaff, AZ
Lines: 29
Keywords: dBaseIII+, Existential Quantifiers
Summary: Finding a record in a set relation in DB3+

In article <2413@mandrill.CWRU.Edu>, ananth@mandrill.CWRU.Edu (ananth srinivasan) writes:
> I have a problem with dBaseIII+ syntax and would appreciate any help.
> I have two relations with join-able attributes (say ID) and I need
> to find out those ID's that exist in one and don't exist in the other.
> In SQL I can use the NOT EXISTS syntax; in QUEL I can use the
> ANY...=0 syntax; and in Rbase V I can use the SUBTRACT operator
> (which really makes the most sense). My question is what is the
> appropriate syntax in dBase?

After setting your relations up, try the following:

select 1
accept 'Enter ID: ' to ID
seek ID
select 2
if eof()
  ? 'That ID is not in the second database.'
endif

This assumes that ID is a character field and that the files
are indexed on ID for both.

If you hve any other problems feel free to contact me.  I have
some friends that do custom dBASE work if you have any good
sized projects.

Bill Wilson
602-523-6461
Bitnet: ucc2wew@nauvm