if ( exists $database->{ $table }{ _unique } ) 
{
    my @unique_fields = @{ $database->{ $table }{ _unique } };
    foreach my $field ( @unique_fields ) 
    {
        my %field_count;
        my $sql = "SELECT $field FROM $table";
        my $fields = $dbh->selectall_arrayref( $sql );
        foreach ( @$fields )
            $field_count{ $_->[0] }++;
        }
        foreach ( keys %field_count ) 
        {
            if ( $field_count{$_} > 1 ) 
            {
                print $err "Table: '$table' Unique field: '$_' was found $field_count{$_} times\n";
                $error_count++;
            }
        }
    } # next $field
}