Study
t/subclass.t
in the distribution.
Tim.
On Sun, Oct 07, 2001 at 10:47:54PM -0700, Jared Still wrote:
>
> I'm having a little trouble with subclassing DBI
> when used with Oracle. After upgrading DBI and DBI::Oracle
> the other day, some code I was working on no longer worked.
>
> I'm rather new to using Perl in an OOP way, and am doing
> so only at the simplest levels rigth now.
>
> Below is some code from a module that I am using to subclass
> the DBI::connect method when used with Oracle.
>
> This code has been reduced to just the relevant bits. Sorry
> if it's still kind of large. The problems I'm having with it
> are detailed in the comments, and more text below the code.
>
> ...
> require DBI;
> @ISA=qw(DBI DBI::db DBI::st);
>
> use Carp;
> use strict;
> use warnings;
> use diagnostics;
>
> sub new {
> my $pkg = shift;
> my $class = ref($pkg) || $pkg;
>
> my ( %args ) = @_;
>
> my $connectionMode = 0;
> if ( exists( $args{MODE} )) {
> if ( $args{MODE} eq 'SYSOPER') { $connectionMode = 4 }
> if ( $args{MODE} eq 'SYSDBA' ) { $connectionMode = 2 }
> }
>
> my $dbh = $class->SUPER::connect(
> 'dbi:Oracle:' . $args{DATABASE},
> $args{USERNAME}, $args{PASSWORD},
> {
> RaiseError => 1, AutoCommit => 0 ,
> ora_session_mode => $connectionMode
> }
> );
>
> croak "Connect to $args{USERNAME} failed \n" unless $dbh;
>
> # blessing $dbh into a class works with
> # DBI 1.13 and DBD::Oracle 1.08
> # works as expected.
> # when DBI is upgraded to 1.20 and DBD::Oracle to 1.12,
> # this no longer works and you must just return the dbh
> # handle. Do not know why yet.
>
> # DBI 1.13; DBD::Oracle 1.08
> my $connection = bless $dbh, $class;
> return $connection;
>
> # works with all, and the only way to do it
> # with DBI 1.20 and DBD::Oracle 1.08 and newer
> #return $dbh;
>
> }
>
> Here's an example of making a connection with this method
> and then disconnecting:
>
> my $dbh = new PDBA::CM(
> DATABASE => 'ts01',
> USERNAME => 'scott',
> PASSWORD => 'tiger',
> );
>
> $dbh->disconnect;
>
> This worked fine on older versions of DBI 1.13 and DBD::Oracle 1.08
>
> With DBI 1.20 and DBD::Oracle 1.12 however, the following error message
> is thrown upon disconnect when the connection module returns a blessed
> $connection:
>
> Uncaught exception from user code:
> DBI->disconnect is not a DBI method. Read the DBI manual. at test.pl line
> 37
> Carp::croak('DBI->disconnect is not a DBI method. Read the DBI manual.')
> called at /usr/lib/perl5/site_perl/5.6.0/i586-linux/DBI.pm line 474
> DBI::disconnect('PDBA::CM=HASH(0x83520ac)') called at test.pl line 37
> Issuing rollback() for database handle being DESTROY'd without explicit
> disconnect() at /usr/lib/perl5/5.6.0/Carp.pm line 119.
> make: *** [test_dynamic] Error 255
>
> The workaround for this is to return the handle $dbh rather than the
> blessed handle as I had done before, which interestingly enough seems
> to work for all versions of DBI/DBD::Oracle that I have tried.
>
> If I'm just doing something wrong here, I'm sure someone will take
> the opportunity to correct me. :)
>
> TIA
>
> Jared
>
>
>
>
>
