y @AssignmentIDs = ();
my $GetAssignmentID_sth=$query_dbh->prepare($SQL);
$GetAssignmentID_sth->execute();
{
   my $rows = $GetAssignmentID_sth->rows;
     if($rows > 0) {
       while (my ($AssignmentID, $UserCount) = $GetAssignmentID_sth-> fetchrow_array() )  {
          push(@AssignmentIDs, $AssignmentID);
       }
     }
}
my $AssignmentIDs = join(",",@AssignmentIDs);
$GetAssignmentID_sth->finish();