Message: Call to a member function row() on boolean

Hey guys, took me the entire week to get familiarise with your CI FrameWork. However been having an issue with fetching and inserting data into the sqli database... I checked the Database connectivity config file and it seems fine.

anyways this is my issue below:
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An uncaught Exception was encountered
Type: Error

Message: Call to a member function row() on boolean

Filename: /application/models/Login_model.php

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and this is my code:

<?php

class login_model extends CI_Model
{
function cek_login($where)
{

$this->db->order_by('user_name', 'DESC');
print_r($this->db->get_where('admin', $where)->row());
$query=$this->db->get_where('admin', $where)->row_array();

$data = array();
if($query !== FALSE && $query->num_rows() > 0){
foreach ($query->result_array() as $row) {
$data[] = $row->row_array();
}
}

return $data;

}
}
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anywayz hope someone out there with enough experience is able to really help me solve this.