sort varchar column codeigniter - php

Question

i first checked if there any same problems like mine i ddnt find anything.
all are sorting alphanumeric column mixed with numeric data.
here is my problem.
i have a table that contain column A datas like this.
WRG-01 WRG-39 WRG-22 WRG-45 WRG-43
need to sort that as
WRG-01 WRG-22 WRG-39 WRG-43 WRG-45
this is the code i using so far in codeigniter frame work
$data['products'] = $this->db->order_by('product_id', 'asc')->get('products');
in mysql i can use this query to get done my work
preg_replace("/[^\d]/", "",'product_id'), 'asc')
How to apply it to my above codeigniter code?
here is search funtion
public function search()
{
$data['title'] = 'Search Product';
$product_name = $this->input->get('product_name');
$product_id = $this->input->get('product_id');
$product_category = $this->input->get('product_category');
$secondCategory = $this->input->get('secondCategory');
$thirdCategory = $this->input->get('thirdCategory');
$data['category'] = $this->db->order_by('id', 'asc')->get_where('categories', ['parent' => 0]);
if($product_category != '')
{
$data['secondCategory'] = $this->db->get_where('categories', ['parent' => $product_category]);
}
if($secondCategory != '')
{
$data['thirdCategory'] = $this->db->get_where('categories', ['parent' => $secondCategory]);
}
if($product_name != '')
{
$this->db->like('product_name', $product_name);
}
if($product_id != '')
{
$this->db->where('product_id', $product_id);
}
if($product_category != '')
{
$this->db->where('product_category', $product_category);
}
if($secondCategory != '')
{
$this->db->where('secondCategory', $secondCategory);
}
if($thirdCategory != '')
{
$this->db->where('thirdCategory', $thirdCategory);
}
$data['products'] = $this->db->order_by('product_id' 'asc')->get('products');
theme('all_product', $data);
}
i can't use sql query here because products is result array from product table.

Answer 1

Use MySQL cast
cast(product_id as SIGNED)
or
cast(product_id as UNSIGNED)
Try query like that :-
select * from products cast(product_id as UNSIGNED) ASC|DESC

Answer 2

Try this
$query= $this->db->query("SELECT * FROM products WHERE ??==?? ORDER BY product_id ASC");
$result= $query->result_array();
return $result;
as default data will sort by Ascending Order
This is in model. So if you pass it to controller it will return data as Objective Array.
So in controller you can access
$result = $this->model_name->method_for_above_code();
$name = $result[0]['name'];
$id = $result[0]['id'];
if in View
$result['this_for_view'] = $this->model_name->method_for_above_code();
foreach ($this_for_view as $new_item) {
echo "Name is ".$new_item['name'];
echo "ID is ".$new_item['id'];
}