计算评论id并按博客id对查询进行分组。

public function get_entry(){

        $id = $this->input->post('ID', true);

        $this->db->select('u.*, a.*, count(b.ID) as total');
        $this->db->where('u.ID', $id)
         ->from('gb_blod as u')
         ->join('gb_users as a', 'u.user_email = a.email', 'LEFT')
         ->join('gb_comments as b', 'u.ID = b.journal_id', 'LEFT')
         ->group_by('u.ID');
         $result = $this->db->get();

            if($result->num_rows() > 0){

            return $result->result_array();

            }else{

                return false;
            }

    }

尝试使用此选项，您可以根据您的请求更改查询quirement:-

$usr_flds = "count(u.ID) as count_rows";
  $this->db->select('usr_flds');
  $this->db->where('u.ID', $id)
 ->from('gb_blod as u')
 ->join('gb_users as a', 'u.user_email = a.email', 'LEFT')
 ->join('gb_comments as b', 'u.ID = b.journal_id', 'LEFT');
   $result = $this->db->get();
   return $res->num_rows();

试试这个。我希望对你有用。

$result = $this->db->get();
 $count = $result->get()->num_rows();
        return [$result, $count];