sybperl-l Archive

From: Andrew dot Crossland at citicorp dot com
Subject: Callbacks in Sybase::Simple
Date: Jan 15 2001 4:27PM

I have a problem which I hope someone out there can help me with. I have 
extended the Sybase::Simple class and provided a new one for my 
application called DBConnection as per code below:-

package DBConnection;

@ISA         = qw(Sybase::Simple Exporter);

sub new
{
....
  my $type = shift;
....
  my $self = Sybase::Simple->new ($user, $passwd, $server);
....
  Sybase::Simple::ct_callback(CS_SERVERMSG_CB, \&serverCBH);
  bless $self, $type;
}

sub ExecSql
{
  my $self=shift;
....
   $retRef = $self->SUPER::ExecSql(@_);
....
}

sub printCallback()
{
     my $self = shift; 
     my ($dbh, $number, $severity, $state, $line, $server, $proc, $msg) = 
@_;

     print "printCallback: $number $msg\n";
}

# NB: Not called as a method
sub serverCBH
{
   my ($dbh, $number, $severity, $state, $line, $server, $proc, $msg) = @_;
....
   $dbh->printCallback(@_);
}

If I run the following code:-
{
  my $dbh = DBConnection->new ($user, $passwd, $server);

  $dbh->ExecSql("use mydatabase");
  $dbh->ExecSql("some sql that causes an insert of a duplicate row into a 
table");
}

I get the following results:

printCallback: 5701 Changed database context to 'mydatabase'.
Can't locate auto/Sybase/CTlib/printCallback.al in @INC (@INC 
contains: /apps/perl/PA-
RISC1.1 /apps/perl /apps/CEDEV/CEDEV_RUN_MENU/release
 /apps/CEDEV/CEDEV_RUN_MENU/perl /home01/acrossla/lib /apps/perl/lib/site_p
erl/PA-RISC1.1 /apps/perl/lib/site_perl /opt/perl5/lib/PA
-RISC1.1/5.00404 /opt/perl5/lib /opt/perl5/lib/site_perl/PA-
RISC1.1 /opt/perl5/lib/site_perl .) ...propagated at /apps/CEDEV/CEDEV_R
UN_MENU/perl/CEProcessor.pm line 111,  chunk 7.

If I run the code in debug and stop in DBConnection::serverCBH and do 
a 'print $dbh' then I get DBConnection=HASH(0x40555fe0) for the first 
ExecSql and Sybase::CTlib=HASH(0x405608d4) for the second ExecSql. So, I'm 
a little confused at to how/why perl thinks that $dbh is a DBConnection 
object one time and a Sybase::CTlib object the second time. Does anyone 
have any help, please!!! Should I be downcasting in someway? I have looked 
through the OO stuff and can't find any information. The best way I can
make it work is to change the line in serverCBH to
$dbh->DBConnection::printCallback(@_)

Thanks V.much,

Andrew.