my $q = new CGI;
    my %vars = $q->Vars; # Fetch all CGI parameters
    my %db_vars = pop_defaults(); # Fetch from database
  
    # Override defined values from database
    $vars{$_} = $db_vars{$_} for (keys %db_vars);

    # Fetch all defaults from the DB and return as a hash ref
    sub pop_defaults { my $r = { }; ... return $r }

##</code><code>##

    $vars{$_} = $db_vars{$_} // $q->param($_) for ($q->param);

##</code><code>##

    %vars{keys %db_vars} = values %db_vars;