codeigniter多表更新查询

Question

这是我的代码

$RestaurantId=14;
$data['status']=0;

$this->db->set('a.status', $data['status']);
$this->db->set('b.status', $data['status']);
$this->db->where('a.id', $RestaurantId);
$this->db->join('b','a.id = b.business_location_id');
$result =$this->db->update('b_locations_info as a,b_images as b');

错误：

表kpbaiger.b_locations_info as a,b_images不存在 在SQL上：

  

更新b_locations_info as a,b_images为b设置a。status ='0'，b。status ='0'   在a。id ='14'