python - 无法分配 "": "Model.user"必须是 "User"实例

Question

创建模型的第一个条目会抛出错误

我执行了以下命令进行迁移

manage.py makemigrations
manage.py migrate

在我执行这些命令以在数据库中创建第一个“数据”之后，一切正常

manage.py shell
from sms.models import Post
from django.contrib.auth.models import User
post_1 = Post(name="testname", email="testemail", gender="Monsieur", number="23233", author=User)

它给了我这个错误:

ValueError: Cannot assign "<class 'django.contrib.auth.models.User'>": "Post.author" must be a "User" instance.

models.py 文件

from django.db import models
from django.contrib.auth.models import User

THE_GENDER = [
    ("Monsieur", "Monsieur"),
    ("Madame", "Madame")
]


class Post(models.Model):


    name = models.CharField(max_length=100)
    email = models.CharField(max_length=100)
    gender = models.CharField(max_length=8, choices=THE_GENDER)
    number = models.CharField(max_length=100)
    author = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.name

Answer 1

您看到此错误是因为您尝试将类对象分配给 author 属性。但它假设是用户实例。所以你应该先创建用户记录并使用它，而不是这样:

user = User.objects.create_user(username="name", email="email@mail.com", password="Pass12345")
post_1 = Post(name="testname", email="testemail", gender="Monsieur", number="23233", author=user)

您可以将模型类视为数据库表。而模型实例代表该表中的记录。