问获取id的数据，并包含在Codeigniter的update_batch中

EN

public function updateCart($data)
  {

    for($i=0;$i < count($data['id']);$i++)
    {

      // select the product ID
      $this->db->select('product_id')->from('shopping_cart');
      $this->db->where('id',$data['id'][$id]);
      $query = $this->db->get();
      $productID = $query->row_array()['product_id'];

      // now select the cost of the item from DB
      $this->db->where('id',$productID);
      $this->db->select('price')->from('products');
      $query = $this->db->get();
      $productPrice = $query->row_array()['price'];

      // now calculate your total as:
      $total = $productPrice * $data['quantity'][$i];

      // and include it on the array as:
      $batch[] = array('id' => $data['id'][$i],
              'quantity' => $data['quantity'][$i],'total_price' => $total
              );
    }

    $this->db->update_batch($this->table , $batch ,'id');
  }