如何通过执行group_by获取所有内容 - CodeIgniter

I am working in codeigniter my problem is i have a query in which i am performing group_by('content_id'), i need to display all the content of same content_id seperately but its showing content of only first row of that group. Pls help.

Below is my Model

public function get_content(){
        $this->db->select('*');
        $this->db->from('content');
        $this->db->order_by('content_id', 'ASC');
        $this->db->group_by('content_id');
        $query = $this->db->get();
        return $query->result();
    }

GROUP_CONCAT is what you need.

$this->db->select('GROUP_CONCAT(column_name separator ", ") as alias',FALSE) // FALSE to protect the backticks