my $sql_select = "select * from $tableName";

 	my $sth = $db->do($str_select);

        $sql_delete = "delete from $tableName where LiftChr=? and LiftPos=?";

 	my $sth1 = $db->prepare($sql_delete);

  	while ($snp = $sth->fetchrow_hashref) {

          $sth1->execute($sql_delete, undef, $snp->{'LiftChr'}, $snp->{'LiftPos'});
	}