sub _upgrade_data { #class method
my ($class, %opts) = @_;
- my $sql = 'UPDATE h_cust_main SET paycvv = NULL';
+ my $sql = 'UPDATE h_cust_main SET paycvv = NULL WHERE paycvv IS NOT NULL';
my $sth = dbh->prepare($sql) or die dbh->errstr;
$sth->execute or die $sth->errstr;