There are two possibilities ('A' for automatic and 'M' for manual) in the database that are selected from a form entry. But for some database entries, there is only one, and I can't know that until I query the database. In case the user selects one that doesn't exist, how do I iterate through the results more than once?

transmission.pm

# this is functioning now
# get $results from Mojo::Pg
my $results = $db->select('w_fuellmengen', undef, {fuellmengen_typ => $car->{'fztyp_typschl'}});
my $hash;
# process rows with Mojo::Pg::Results
while (my $next = $results->hash) {
  # try form value
  if ($next->{fuellmengen_getriebe} eq $self->param('trans')) { 
        $hash = $next;
  }
  # try auto
  elsif ($next->{fuellmengen_getriebe} eq 'A') { 
        $hash = $next unless($hash);
  }
  # try manual
  elsif ($next->{fuellmengen_getriebe} eq 'M') { 
        $hash = $next unless($hash);
  }
}
return ($hash);