perl dbi sybase error handling question

[G S]

I don't understand something.  I am executing a sybase stored procedure. 
While testing, I am forcing various error conditions.  In a couple cases I 
am puzzled about the outcome.

Here is the execute statement.  I was getting results I did not understand, 
so I decided to capture $retCode and take a look at it.  I also repeated the 
printf statement so I could see err and errstr even when the error handler 
was not executed.

# Execute query and handle error condition. Capture $retCode for later 
examination.

$retCode = $sth->execute() ||
printf("<BR>##### Trouble with dbh->execute():<br>" .
 "dbh->err= '%s'<br>" .
 "dbh->errstr= '%s'<br>",
 $dbh->err,
 $dbh->errstr
);
# Examine $retCode, err, and errstr

print "<BR>after execute retCode is: $retCode <br>";
printf("dbh->execute():<br>" .
"dbh->err= '%s'<br>" .
"dbh->errstr= '%s'<br>",
$dbh->err,
$dbh->errstr
);
scenario 1 ------------------------------------------
Here is the output from successful execution.  You can see that the error 
handler part is not executed.  $retCode is -1.

after execute retCode is: -1
dbh->execute():
dbh->err= ''
dbh->errstr= ''
scenario 2 ------------------------------------------
Here I deliberately passed an incorrect data type as a parameter to the 
stored procedure.  As you can see, there was an error, but it was not caught 
by the error handling code (after the "||").  It seems strange to me that 
retCode is -1.

after execute retCode is: -1
dbh->execute():
dbh->err= '257'
dbh->errstr= 'Server message number=257 severity=16 state=1 line=0 
server=SCATS1P_SQL procedure=sc_deal_update text=Implicit conversion from 
datatype 'VARCHAR' to 'SMALLINT' is not allowed. Use the CONVERT function to 
run this query.'

scenario 3 ------------------------------------------
Here I deliberately changed the stored procedure name to an incorrect one. 
This time the error handling code (after the "||") is executed.  Oddly, 
$retCode is 1.  I would think that the error handler would get executed only 
if $retCode is 0 or empty.  What's going on here?

##### Trouble with dbh->execute():
dbh->err= '2812'
dbh->errstr= 'Server message number=2812 severity=16 state=5 line=22 
server=SCATS1P_SQL text=Stored procedure 's_deal_update' not found. Specify 
owner.objectname or use sp_help to check whether the object exists (sp_help 
may produce lots of output). '

after execute retCode is: 1
dbh->execute():
dbh->err= '2812'
dbh->errstr= 'Server message number=2812 severity=16 state=5 line=22 
server=SCATS1P_SQL text=Stored procedure 's_deal_update' not found. Specify 
owner.objectname or use sp_help to check whether the object exists (sp_help 
may produce lots of output). '

Thanks!





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