He usado la siguiente consulta en mi modelo, pero cuando combino mis resultados, solo devuelve la última consulta.

 $this->db->where('type','user'); $this->db->where('status','Approve'); $this->db->select('*'); $this->db->from('trending_update'); $this->db->order_by('trending_update.update_time','DESC'); $this->db->join('user_profile', 'user_profile.id = trending_update.user_id'); $query = $this->db->get(); $data_user= $query->result(); $this->db->where('type','employer'); $this->db->where('status','Approve'); $this->db->select('*'); $this->db->from('trending_update'); $this->db->order_by('trending_update.update_time','DESC'); $this->db->join('event_master', 'event_master.employer_id = trending_update.user_id','left outer'); $this->db->join('employer_profile', 'employer_profile.id = trending_update.user_id','left outer'); $this->db->join('news_master', 'news_master.employer_id = trending_update.user_id','left outer'); $this->db->group_by('employer_profile.id'); $query = $this->db->get(); $data_employer = $query->result(); $data_all=$data_employer+$data_user;