Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!gatech!gitpyr!mlw
From: mlw@pyr.gatech.EDU (Michael Williams)
Newsgroups: comp.lang.pascal
Subject: Re: Deleting records from TYPED file
Summary: Use "truncate"
Keywords: turbo pascal
Message-ID: <9094@pyr.gatech.EDU>
Date: 31 Aug 89 00:20:52 GMT
References: <833@cbnewse.ATT.COM>
Reply-To: mlw@pyr.UUCP (Michael Williams)
Distribution: usa
Organization: Georgia Institute of Technology
Lines: 20

In article <833@cbnewse.ATT.COM> rtf1@cbnewse.ATT.COM (richard.t.ferber) writes:
>
>I am writing a simple database program in Turbo Pascal (version 5) that
>uses a TYPED file to store data records. One of the basic operations I
>want the program to do is to delete records in the file (along with add,
>update, etc.). 

  It depends on how you are storing your records.  If you are trying to keep
them in some kind of order, it will be necessary to 'slide' them all down
one and call truncate at the last position in the file.  Otherwise, you
could just swap the last record for the one to be deleted, and then do the
truncate.  Another approach is to have a boolean 'used' in each record to
simply mark deleted ones, taking care of the actual deletion at a later time
to improve efficiency.  Hope this helps ...

-- 
Michael Williams
Georgia Insitute of Technology, Atlanta Georgia, 30332
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