db to passwd comparison

[Rob]

Hi, I'm trying to find out which users in a passwd file are not in a
database.  What I've tried so far(see below) finds a few but misses even
more.  I'm thinking it might be the way I'm preparing the statement or
perhaps executing it?  Something else all together?  Any help appreciated.

<snip>
$sql = $dbh->prepare_cached("SELECT CustNo, UserName FROM call_log WHERE
    UserName = ?");

open(IN, "passwd") || die "Can't open passwd file:$!\n";
open(OUT, ">usernames.db") || die "Can't create output file:$!\n";
while(<IN>) {
    chomp;
    ($userP, $group) = (split /:/)[0,3];
    $grps{$group}++;
    $sql->execute($userP)
            or warn "Can't execute select " . $sql->errstr;
    $userD = $sql->fetchrow_array();
    if($userD eq "") {
        print OUT "UserP:$userP - UserD:$userD\n";
    }
    $sql->finish;
}
close(OUT);
close(IN);
</snip>

Thanks,
--
Rob