解决多对多关系的问题

Question

我有这些模型，例如产品，订单和order_lines。订单模型通过称为产品的ManyToManyField链接到产品模型。 这是模型。 但是，当我运行makemigrations and migration命令时，无法在表顺序中看到现场产品。我删除了两次数据库，删除了迁移文件，然后重新运行迁移，仍然遇到相同的错误。我修改了模型订单并再次运行，但出现以下错误：  “通过=在M2M字段上）”％（old_field，new_field） ValueError：无法将字段page.Orders.products更改为pages.Orders.products-它们是不兼容的类型（您不能在M2M字段之间来回更改，也不能在M2M上添加或删除through = 字段）

class StatusCode(models.Model):
    """
    The StatusCode model represents the status of an order in the system.
    This field is intended to function as a tracking system.
    """
    short_name = models.CharField(max_length=10)
    name = models.CharField(max_length=300)
    description = models.TextField()


class Orders(models.Model):
    """
    The Order model represents a customer order. It includes a
    ManyToManyField of products the customer is ordering and stores
    the date and total price information.
    """
    customer= models.ForeignKey(User, on_delete=models.CASCADE)
    status_code = models.ForeignKey(StatusCode, on_delete=models.CASCADE)
    orderDate = models.DateTimeField()
    total_price = models.DecimalField(max_digits=7, decimal_places=2)
    comment=models.TextField(blank=True)
    products=models.ManyToManyField(Product, blank=True, through='Order_lines')

class Order_lines(models.Model):
    """
    The Order_line model represents information about a specific product ordered by a customer.
    """
    order = models.ForeignKey(Orders, on_delete=models.CASCADE)
    product=models.ForeignKey(Product, on_delete=models.CASCADE)
    unit_price = models.DecimalField(max_digits=7, decimal_places=2)
    total_price = models.DecimalField(max_digits=7, decimal_places=2)
    quantity = models.PositiveIntegerField()
    comments = models.TextField(blank=True)

这是餐桌顺序的屏幕截图。

请问这是什么错误？