Codeigniter error Message: Undefined property: stdClass::$members_id - php

Question

I got this error message when running PHP Code Igniter project:
A PHP Error was encountered
Severity: Notice
Message: Undefined property: stdClass::$members_id
Filename: models/mtree.php
Line Number: 33
In line 33 ($row->members_id) refer to field in my database
VALUES (" . $this->db->escape($row->members_id) . ", " . $this->db->escape($left_parent) . ")";
My model function is:
function insert_to_right($direct_id='members_direct_id') {
$left_parent = $this->get_right_parent('members_id');
$row->members_direct_id = $left_parent;
$row->members_spillover_id = $left_parent;
$this->db->insert('ajmatrix_members_table', $row);
$sql = "INSERT INTO ayman_mot (child, parent)
VALUES (" . $this->db->escape($row->members_id) . ", " . $this->db->escape($left_parent) . ")";
$this->db->query($sql);
}

Answer 1

Your code don't have the members_id property in row.
$row variable have only 2 properties:
$row->members_direct_id = $left_parent;
$row->members_spillover_id = $left_parent;

Answer 2

Somewhere in your Model where you have the db select statement, for example:
$this->db->select('field1, field2, field3, field4');
try and replace it with:
$this->db->select('*');
Worked out for me, after battling it out for weeks through forums.
Though my initial mistake was putting the statement like this:
$this->db->select('field1', 'field2', 'field3', 'field4');
~ Mistakes are the ones we make ~ (speaking for myself here, don't hit me ^_^ )
Best Regards

Answer 3

You're not defining $row->members_id in your code - elsewhere you're referencing a members_direct_id - is that what you meant to use perhaps?