Question

I have piece of PHP code written in Codeigniter framework that returns nothing (an empty set).
Have a look at it and tell me what is wrong with it.

function sbsn($serial){
    $this->db->select('asset_types.name as type_name,asset_brands.name as brand_name');
    $this->db->from('asset_types,asset_brands,assets');
    $this->db->where('assets.type_code','asset_types.code');
    $this->db->where('assets.brand_code','asset_brands.code');
    $this->db->where('serial_no',$serial); 
    $result = $this->db->get();
    return $result;
}

Answer 1

The problem can be easily solved by joining the tables in the following way.

$this->db->select('at.name as type_name,ab.name as brand_name');
$this->db->from('asset_types as at,asset_brands as ab');
$this->db->join('assets as a', 'a.type_code = at.code and a.brand_code as ab.code');
$this->db->where('a.serial_no',$serial); 
$result = $this->db->get()->result_array();
return $result;