django models.py-從一個模型類遷移到另一個模型類

Question

我正在嘗試分解現有的模型類。 原始類不是最佳選擇，因此我想將所有與客戶相關的信息從CustomerOrder移到新類Customer中。 在Django中執行此操作的最佳方法是什么？

舊模型類：

class CustomerOrder(models.Model):

    # Customer information fields
    first_name = models.CharField(max_length=200)       # Customer first name
    last_name = models.CharField(max_length=200)        # Customer last name
    email = models.EmailField()                 # Customer email address
    address = models.CharField(max_length=255)      # Address to deliver (e.g. 1532 Commonwealth St. Apt 302)
    city = models.CharField(max_length=200)         # City to deliver   (e.g. Fullerton, CA 92014)

    # Order information fields
    note = models.TextField()           # Any notes the customer may have about shipping
    shipping_method = models.CharField(max_length=200)      # Shipping in LA or OC
    total_price = models.FloatField(default=0)              # Total price of the order
    delivery_date = models.DateField()  # When to deliver the order. Order is "live" until the next 
                            # day after delivery. So if delivery date is Jan 3, it's "live" until Jan 4.

    order_date = models.DateField()     # When the customer ordered
    time_slot = models.CharField(max_length=200)            # What time to deliver the product
    is_cancelled = models.BooleanField(default=False)       # If the order is cancelled or refunded, we mark it here.

    created_at = models.DateTimeField(auto_now_add=True)    # When the order entry was saved into database
    updated_at = models.DateTimeField(auto_now=True)        # When the order was last updated in database

    def __str__(self):
        return self.first_name + " " + self.last_name

新模型類別：

class Customer(models.Model):
    first_name = models.CharField(max_length=200)       # Customer first name
    last_name = models.CharField(max_length=200)        # Customer last name
    email = models.EmailField()                 # Customer email address
    address = models.CharField(max_length=255)      # Address to deliver (e.g. 1532 Commonwealth St. Apt 302)
    city = models.CharField(max_length=200)         # City to deliver   (e.g. Fullerton, CA 92014)

在舊模型中有重復項，因此我也希望將其刪除。

Answer 1

這取決於您的數據庫類型。 讀這個

您應該小心不要丟失數據！

Answer 2

我認為問題更多與整個關系數據庫架構有關。

我會將所有與客戶相關的東西都放在一個表中，就像您擁有的新CustomerOrder（將其重命名為Customer）類一樣，然后為Orders創建另一個類，然后將它們與一對多關系鏈接起來。 例如，一個客戶可以下很多訂單。 如果要實現這種一對多關系，只需將以下內容添加到訂單類：

class Order(models.Model):
    # The relavant order fields which you require, i.e. order number etc.
    customer = models.ForeignKey(Customer, on_delete=models.CASCADE)

現在，當您創建新的訂單實例時，您可以分配客戶。 ps可以反向訪問，即從客戶到訂單，您基本上可以使用customer.order_set（）方法（客戶可以下很多訂單）。