/**
* 获取购物车中某个商品的数量
*
* @param string $goodsId
* @return integer
*/
public function getCartGoodsQuantity($goodsId)
{
$quantity = (int) CartGoods::find()->select('count')->where(['goods_id' => $goodsId, 'user_id' => $this->id])->scalar();
return $quantity;
}
