$query .= ' where upper(env)=upper(?)';
  push(@sql_params,$query(env});
  ...

  my $sth = $dbh->prepare($query) or die;
  $sth->execute(@sql_params);

##</code><code>##

if (defined($query{component}))
  push(@querypart, 'where upper(component) = upper(?)';
  push(@sql_params,$query{component});
}
if (defined($query{env})) {
  push(@querypart, 'where upper(env) = upper(?)';
  push(@sql_params,$query{env});
}

$query = 'SELECT * FROM or_mod ' .
         join(' AND ',@queryparts) .
         ' order by env, application, component, mod_date, desc';

print $query;
my $sth = $dbh->prepare($query); 
$sth->execute(@sql_params);