sub AUTOLOAD {
   my $method = substr($AUTOLOAD, rindex($AUTOLOAD, '::')+2);
   my $code_ref = DBI::db->can($method);

   if (!$code_ref) {
      require Carp;
      Carp::croak("Undefined subroutine $method called");
   }

   # This only works with methods,
   # and only if they are non-static
   # (just like your code).
   local $_[0] = $_[0]->{DBH};
   
   goto($code_ref);
}