Trial Balance Update accounts

Question

Am looking to update my chartofaccount to get an trial balance here what i have in the table of chartofaccount

Id             parent         Debit          Credit

1
10              1              
101             10
1011            101                          30
101121231       1011          40
101134121       1011          20

i need the table to look like this

Id             parent         Debit          Credit

1                             60             30
10              1             60             30
101             10            60             30
1011            101           60             30
101121231       1011          40
101134121       1011          20

The idea is that i need to sum the account Id with respect to the parent

here what am using but its just updating 1 record

    $select2="SELECT sum(debit),sum(credit),parent
                    FROM chartofaccount
                    group by parent
                    ORDER BY parent DESC";
    $run2=mysql_query($select2,$con);
    if(!$run2)die("ERROR22".mysql_error());

    for($counter=0;$row1=mysql_fetch_array($run2);$counter++){

        $parentid=$row1[2];
        $update3="UPDATE chartofaccount
                    SET debit='$row1[0]',
                        credit='$row1[1]'
                        WHERE Id='$parentid'";
        $run3=mysql_query($update3,$con);
        if(!$run3)die("ERROR1".mysql_error());

    }

Answer 1

$select2="SELECT Distinct(parent) FROM chartofaccount
                            ORDER BY parent DESC";
            $run2=mysql_query($select2,$con);
            if(!$run2)die("ERROR22".mysql_error());

            for($counter=0;$row1=mysql_fetch_assoc($run2);$counter++){

                $parentid=$row1['parent'];

                $select3="SELECT sum(debit),sum(credit),parent
                            FROM chartofaccount
                            WHERE parent='$parentid'
                            group by parent";
                $run3=mysql_query($select3,$con);
                if(!$run3)die("ERROR22".mysql_error());

                for($counter=0;$row2=mysql_fetch_array($run3);$counter++){

                        $parentidz=$row2[2];

                            $update3="UPDATE chartofaccount
                                        SET debit='$row2[0]',
                                            credit='$row2[1]'
                                            WHERE Id='$parentidz'";
                            $run4=mysql_query($update3,$con);
                            if(!$run4)die("ERROR1".mysql_error());
                }
            }