sub addAtom{
    my $self = shift;
    my $pdb = shift;
    my $atom = shift;
    my $ch = $atom->chainId();
    my $dbh = DBI->connect($dbi,$u,$p,{'RaiseError' => 1});
    my $cid = $self->getCID($pdb,$atom->chainId(),$dbh);
    my ($rid,$aid,$mid,$res,$ato);
    if(!$cid){
        $dbh->do("INSERT INTO chain (pdb,chain) VALUES ('$pdb','$ch')");
        $cid = $self->getCID($pdb,$atom->chainId(),$dbh);
    }
    if($cid){
        $rid = $self->getRID($cid,$atom->resNumber,$atom->resName,$dbh);
        if(!$rid){
            $res=$dbh->quote($atom->resName());
            $dbh->do("INSERT INTO residue (cid,rnumber,rname) VALUES ('$cid','".$atom->resNumber."',$res)");
            $rid = $self->getRID($cid,$atom->resNumber,$atom->resName,$dbh);
        }
 
        if($rid){
            $aid = $self->getAID($rid,$atom->atomName,$dbh);
            if(!$aid){
                $ato=$dbh->quote($atom->atomName());
                $dbh->do("INSERT INTO atom (rid,aname) VALUES ('$rid',$ato)");
                $aid = $self->getAID($rid,$atom->atomName,$dbh);
            }
             
            if($aid){
                $mid = $self->getMID($aid,$atom->model,$dbh);
                if(!$mid){
                    $dbh->do("INSERT INTO model (aid,model,x,y,z) VALUES ('$aid','".$atom->model."','".$atom->x."','".$atom->y."','".$atom->z."')");
                    $mid = $self->getMID($aid,$atom->model,$dbh);
                }
            }
        }
    }
    $dbh->disconnect();
}