python - 更改 model.py 中的类名后，无需在 Django 中应用任何迁移

Question

在我将class BillingAddress 的名称更改为class Address 后。并尝试了这些阶段

1. 从应用的迁移目录中删除了所有迁移记录。

2. 还删除了 db.sqlite3 文件。

然后，我执行了以下命令

python manage.py makemigrations core
python manage.py migrate

迁移后，不再显示插入的数据，而是显示没有要应用的迁移。 在终端

PS C:\Users\Dell\project5> python manage.py makemigrations core
Migrations for 'core':
  core\migrations\0001_initial.py
    - Create model Address
    - Create model Coupon
    - Create model Item
    - Create model Order
    - Create model Refund
    - Create model Payment
    - Create model OrderItem
    - Add field items to order
    - Add field payment to order
    - Add field shipping_address to order
    - Add field user to order
PS C:\Users\Dell\project5> python manage.py migrate
Operations to perform:
  Apply all migrations: account, admin, auth, contenttypes, core, sessions, sites, socialaccount
Running migrations:
  No migrations to apply.
PS C:\Users\Dell\project5>

当我点击添加到购物车按钮时，它显示错误为

OperationalError at /add-to-cart/test-product-4/ table core_order has no column named shipping_address_id

模型.py

from django.conf import settings
from django.db import models
from django.db.models import Sum
from django.shortcuts import reverse
from django_countries.fields import CountryField

# Create your models here.
CATEGORY_CHOICES = (
    ('SB', 'Shirts And Blouses'),
    ('TS', 'T-Shirts'),
    ('SK', 'Skirts'),
    ('HS', 'Hoodies&Sweatshirts')
)

LABEL_CHOICES = (
    ('S', 'sale'),
    ('N', 'new'),
    ('P', 'promotion')
)

ADDRESS_CHOICES = (
    ('B', 'Billing'),
    ('S', 'Shipping')
)


class Item(models.Model):
    title = models.CharField(max_length=100)
    price = models.FloatField()
    discount_price = models.FloatField(blank=True, null=True)
    category = models.CharField(choices=CATEGORY_CHOICES, max_length=2)
    label = models.CharField(choices=LABEL_CHOICES, max_length=1)
    slug = models.SlugField()
    description = models.TextField()
    image = models.ImageField()

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse("core:product", kwargs={
            'slug': self.slug
        })

    def get_add_to_cart_url(self):
        return reverse("core:add-to-cart", kwargs={
            'slug': self.slug
        })

    def get_remove_from_cart_url(self):
        return reverse("core:remove-from-cart", kwargs={
            'slug': self.slug
        })


class OrderItem(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL,
                             on_delete=models.CASCADE)
    ordered = models.BooleanField(default=False)
    item = models.ForeignKey(Item, on_delete=models.CASCADE)
    quantity = models.IntegerField(default=1)

    def __str__(self):
        return f"{self.quantity} of {self.item.title}"

    def get_total_item_price(self):
        return self.quantity * self.item.price

    def get_total_discount_item_price(self):
        return self.quantity * self.item.discount_price

    def get_amount_saved(self):
        return self.get_total_item_price() - self.get_total_discount_item_price()

    def get_final_price(self):
        if self.item.discount_price:
            return self.get_total_discount_item_price()
        return self.get_total_item_price()


class Order(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL,
                             on_delete=models.CASCADE)
    ref_code = models.CharField(max_length=20)
    items = models.ManyToManyField(OrderItem)
    start_date = models.DateTimeField(auto_now_add=True)
    ordered_date = models.DateTimeField()
    ordered = models.BooleanField(default=False)
    shipping_address = models.ForeignKey(
        'Address', related_name='shipping_address', on_delete=models.SET_NULL, blank=True, null=True)
    billing_address = models.ForeignKey(
        'Address', related_name='billing_address', on_delete=models.SET_NULL, blank=True, null=True)
    payment = models.ForeignKey(
        'Payment', on_delete=models.SET_NULL, blank=True, null=True)
    coupon = models.ForeignKey(
        'Coupon', on_delete=models.SET_NULL, blank=True, null=True)
    being_delivered = models.BooleanField(default=False)
    received = models.BooleanField(default=False)
    refund_requested = models.BooleanField(default=False)
    refund_granted = models.BooleanField(default=False)

    '''
    1. Item added to cart
    2. Adding a BillingAddress
    (Failed Checkout)
    3. Payment
    4. Being delivered
    5. Received
    6. Refunds
    '''

    def __str__(self):
        return self.user.username

    def get_total(self):
        total = 0
        for order_item in self.items.all():
            total += order_item.get_final_price()
        if self.coupon:
            total -= self.coupon.amount
        return total


class Address(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL,
                             on_delete=models.CASCADE)
    street_address = models.CharField(max_length=100)
    apartment_address = models.CharField(max_length=100)
    country = CountryField(multiple=False)
    zip = models.CharField(max_length=100)
    address_type = models.CharField(max_length=1, choices=ADDRESS_CHOICES)
    default = models.BooleanField(default=False)

    def __str__(self):
        return self.user.username

    class Meta:
        verbose_name_plural = 'Address'


class Payment(models.Model):
    stripe_charge_id = models.CharField(max_length=50)
    user = models.ForeignKey(settings.AUTH_USER_MODEL,
                             on_delete=models.SET_NULL, blank=True, null=True)
    amount = models.FloatField()
    timestamp = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.user.username


class Coupon(models.Model):
    code = models.CharField(max_length=15)
    amount = models.FloatField()

    def __str__(self):
        return self.code


class Refund(models.Model):
    order = models.ForeignKey(Order, on_delete=models.CASCADE)
    reason = models.TextField()
    accepted = models.BooleanField(default=False)
    email = models.EmailField()

    def __str__(self):
        return f"{self.pk}"

设置.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'django.contrib.sites',
    'allauth',
    'allauth.account',
    'allauth.socialaccount',
    'crispy_forms',
    'django_countries',
    'core'
]

Answer 1

不应始终执行此操作，但您可以删除迁移文件夹中的所有迁移，但不要删除 init.py。之后，您可以再次运行迁移，它应该可以工作。