use DBI; my $dbh=DBI->connect("dbi:mysql:hostname=localhost;database=somedb","userok","passwdok"); bless $dbh, "My::Special::DBI::db"; print "can error: ", $dbh->can("error"),"\n"; package My::Special::DBI::db; use base qw(DBI::db); sub error { my $dbh=shift; return $dbh->errstr(); }