Php Codeigniter活动记录中的多个Select Count SQL查询

我喜欢将以下MySQL查询转换为Codeigniter活动记录查询

以下是MySQL：

select brand_id,name,(select count(*) from items where brand_id = b.brand_id) as itemc, (select count(*) from models where brand_id = b.brand_id) as modelc from brands as b

编码点火器：

$this->db->limit($perpage,$page);
    $query = 'select brand_id,name,(select count(*) from items where brand_id = b.brand_id) as itemc, (select count(*) from models where brand_id = b.brand_id) as modelc from brands as b limit '.$perpage.' offset '.$page.'';
    $query = $this->db->query($query);
    $query = $query->result();
    return $query;

---

请帮助我将上述代码转换为Codeigniter活动记录。

以下是活动记录中的查询

 $rows =   $this->db->select('b.brand_id,b.name')
    ->select('(select count(*) from items where brand_id = b.brand_id) as itemc',FALSE)
    ->select('(select count(*) from models where brand_id = b.brand_id) as modelc',FALSE)
    ->from('brands as b')
    ->limit($perpage,$page)->get()->result();

---

这是活动记录中的查询

 $rows =   $this->db->select('b.brand_id,b.name')
    ->select('(select count(*) from items where brand_id = b.brand_id) as itemc',FALSE)
    ->select('(select count(*) from models where brand_id = b.brand_id) as modelc',FALSE)
    ->from('brands as b')
    ->limit($perpage,$page)->get()->result();