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.