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sybperl-l Archive

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From: Rob_Osattin at ajc dot com (Rob Osattin)
Subject: Problems with writing text
Date: Jan 25 1996 4:01AM

Date	1/24/96
Subject	Problems with writing text 
From	Rob Osattin
To	Sybperl Mailing List
CC	Keith Dryden, Don Morris

                      Problems with writing text data
Dear fellow Sybperl'ers,

My company uses a turnkey  client/server system with mac clients and Sun
servers running Sybase 10.0 under Solaris.  The software includes sybperl
programs that run under perl 4 to perform limited utility functions but we
wanted more so we wrote a sybperl program ourselves

But it doesn't work right. We're stumped and the vendor is useless. HELP!!

The purpose of the program is to continuously scan directories on the Sun
and copy the contents of all files found to rows in a certain table. Each
file goes into a text column in its own row. What we're seeing is that,
after a while, files are being run together- the text in the most recently
created row includes all the text of every row previously written since the
program was started. This is not good!

I'm suspecting that we've made some mistakes in either the &dbwritetext call
or have done something resulting in memory corruption. By the way, our
debugging shows that the contents of all perl variables are correct before
each call. The text presented to the writetext is, in all cases, what it
should be. It's not run together.

Here's the main logic outline. I'd appreciate any comments or criticisms you
might have. Please, no flames, it's our first sybperl. (I hope my metacode
is okay)

 ($dbproc1)   &dblogin

 ($dbproc2)   &dblogin

 ($dbproc1)   &dbuse

 ($dbproc2)   &dbuse

 ($dbproc1)   &dbsql (cmd+exec)  "set nocount on"
 .
 .
 file loop
    if file in directory

          ($dbproc1) &dbsql (cmd+exec) insert new row into story table
providing values for several columns      ***note the text column is not set
to anything here***

           read the contents of the file into variable $storyText ***this
variable looks fine each time ***

          ($dbproc1)  &dbsql (cmd+exec) update the row, setting a non text
column

          ($dbproc1)  &dbsql (cmd+exec) update the row, setting text column
to NULL

          ($dbproc2)  &dbsql (cmd+exec) select the text column from the row

          if &dbresults($dbproc2) != $NO_MORE_RESULTS
              repeatedly execute  ($dbproc2) &dbnextrow until results are 0
or null
              endif

           &dbwritetext($dbproc1, "story.text',$dbproc2,1,$storyText)  
***actual statement***

           ($dbproc1)  &dbsql (cmd+exec) update the row with additional info
for other colums #1

           ($dbproc1)  &dbsql (cmd+exec) update the row with additional info
for other colums #2

           ($dbproc1)  &dbsql (cmd+exec) update the row with additional info
for other colums #3

       end of "if file in directory"
 end of file loop


Note that we're not using begin trans or commits. Could this be a problem?
Also,  although I didn't show it, we're checking the return status from each
call and are rolling back and exiting if a non zero status is returned.

I apologize for being so wordy here but this is the only way I know to
describe the problem.

I hope you Sybperl gurus can help. If not, I fear my management is going to
be so afraid of development in Sybperl that they'll force us either to C or
*choke* Cobol.

Please save us.

Thanks.

Rob Osattin
Atlanta Journal-Constitution
Atlanta, GA