带相关模型的Django查询

对于以下型号:

class Customer(models.Model):
    id = models.IntegerField(primary_key=True)

class OrderA(models.Model):
    name = models.CharField(max_length=20)
    foo = models.FloatField()
    customer = models.ForeignKey(Customer)
    type = models.IntegerField()

class OrderB(models.Model):
    name = models.CharField(max_length=20)
    customer = models.ForeignKey(Customer)
    type = models.IntegerField()

我想在一个条件中一次性获取所有客户对象及其相关的ordera和orderb对象(其中键入ordera和orderb等于1)