my $sth = $dbh->prepare('SELECT * FROM [Production Words]');
$sth->execute;

# finish the rest of this line after you design the new table
my $new_sth = $dbh->prepare('INSERT INTO new_table ...');

my %hash;
while (my $row = $sth->fetchrow_hashref) {

##</code><code>##

   my ($str,$num) = $row->{ID} =~ /(\D+)(\d+)/;
   my $new_id = lc($str) . int($num);

##</code><code>##

   unless ($hash{$new_id}++) {
      # INSERT $row into the new table 
      $new_sth->execute( ... );
   }
   else {
      # possibly fetch existing row and check to see
      # if this redundant old row has better data
   }
}