my $sth = $dbh->prepare("exec PerlTest2 \@RetVal = ? OUTPUT, \@SomeParam = ? ");

$sth->bind_param(1, undef, SQL_INTEGER);
$sth->bind_param(2, "val1", SQL_VARCHAR);

$sth->execute;   # first batch exec

$sth->bind_param(1, undef);
$sth->bind_param(2, "val22");

$sth->execute;  # exec some more 

$sth->finish;
$dbh->rollback;   # <---- still records get committed into the dB !!!

print "finishing...\n";
$dbh->disconnect;

close dbh;