如果MySQL中的字段为null，则返回0?mysql

在MySQL中，是否可以将“总计”字段设置为零（如果它们为NULL）？

这是我所拥有的：

SELECT uo.order_id, uo.order_total, uo.order_status, (SELECT SUM(uop.price * uop.qty) FROM uc_order_products uop WHERE uo.order_id = uop.order_id ) AS products_subtotal, (SELECT SUM(upr.amount) FROM uc_payment_receipts upr WHERE uo.order_id = upr.order_id ) AS payment_received, (SELECT SUM(uoli.amount) FROM uc_order_line_items uoli WHERE uo.order_id = uoli.order_id ) AS line_item_subtotal FROM uc_orders uo WHERE uo.order_status NOT IN ("future", "canceled") AND uo.uid = 4172; 数据输出正常，但NULL字段应为0。

如何在MySQL中为NULL返回0？