+sub _upgrade_schema {
+ my ($class, %opts) = @_;
+
+ my $sql = '
+ DELETE FROM pkg_referral WHERE NOT EXISTS
+ ( SELECT 1 FROM cust_pkg WHERE cust_pkg.pkgnum = pkg_referral.pkgnum )
+ ';
+
+ my $sth = dbh->prepare($sql) or die dbh->errstr;
+ $sth->execute or die $sth->errstr;
+ '';
+}
+