$dbh->{RaiseError} = 1;
my $sth = $dbh->prepare (qq;
    select tax_id
    from   gene2acc
    where  genomic_ac_ver = '$ref';
    ); # qq;; is a nice way to make cut-n-paste to sql easier
$sth->execute;
my $tax_id;
$sth->bind_columns (\$tax_id);
my %seen;
while ($sth->fetch) {
    $seen{$tax_id}++ and next; # Only use first occurance
    print "Entering taxID_format with $tax_id\n";
   #taxID_format ($tax_id);
    }
keys %seen or print "No records matched for $ref\nn";