Unable to Update and delete in CodeIgniter? - php

Question

I'm new in CodeIgniter, just watched the tutorial on youtube and followed the steps.
I can't edit or delete records of my database. I can insert or fetch records, but update and delete functions always return error. Here is my code
Controller:
function __construct()
{
parent::__construct();
$this->load->model('Danhmuc_model');
}
function xoadm()
{
$id = $this->uri->segment(5);
$this->Danhmuc_model->delete($id);
$this->session->set_flashdata('mess',' Đã xóa thành công');
redirect(admin_url('danhmuc/xemdm'));
}
function suadm()
{
$data = array();
$id = $this->uri->segment(5);
$row = $this->Danhmuc_model->get_info($id);
if($this->input->post())
{
$this->form_validation->set_rules('ten_dm',"Tên danh mục",'required');
if($this->form_validation->run())
{
$tendm = $this->input->post('ten_dm');
$input = array('ten_dm'=>$tendm);
$this->Danhmuc_model->update($id,$input);
$this->session->set_flashdata('mess',' Đã sửa thành công');
}
}
$data['row'] = $row;
$data['temp'] = 'admin/danhmuc/suadm';
$this->load->view('admin/index',$data);
}
Model:
function update($id, $data)
{
if (!$id)
{
return FALSE;
}
$where = array();
$where[$this->key] = $id;
$this->update_rule($where, $data);
return TRUE;
}
/**
* Xoa row tu id
* $id : gia tri cua khoa chinh
*/
function delete($id)
{
if (!$id)
{
return FALSE;
}
//neu la so
if(is_numeric($id))
{
$where = array($this->key => $id);
}else
{
//xoa nhieu row
//$id = 1,2,3...
$where = $this->key . " IN (".$id.") ";
}
$this->del_rule($where);
return TRUE;
}
View:
Edit view:
<td>
<input name="title" class="form-control" type="text" value="<?php echo $row['ten_dm'] ?>">
</td>
If I use this value="<?php echo $row['ten_dm'] ?>", the text box doesn't appear the category's title (I'm inserting and editing categories)
https://imgur.com/lW7FeDA
https://imgur.com/Z6TjnhL
But if I use this value="<?php echo $row->ten_dm ?>", error with this message
A PHP Error was encountered
Severity: Notice
Message: Trying to get property of non-object
Filename: danhmuc/suadm.php
Line Number: 13
I can't understand where is the error, please help me. Thanks in advance.