迁移中缺少外键

Question

我有模型 trade/ Trade .py：

from datetime import datetime
from django.db import models
from home.models import Player


class Trade(models.Model):
    buyer = models.ForeignKey(Player, on_delete=models.CASCADE, related_name='buyer'),
    buyee = models.ForeignKey(Player, on_delete=models.CASCADE, related_name='buyee'),
    date = models.DateTimeField(default=datetime.now)

模型主页/玩家.py：

from django.contrib.auth.models import User
from django.db import models
class Player(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True, related_name='user')
    value = models.IntegerField(default=1500)
    owner = models.OneToOneField(User, on_delete=models.CASCADE, related_name='owner', blank=True, null=True)

交易发生在 2 个Player之间。也就是说，Trade中的buyer和buyee字段是Player的外键。

现在，当我为Trade模型进行迁移时，我得到的是：

class Migration(migrations.Migration):

    initial = True

    dependencies = [
    ]

    operations = [
        migrations.CreateModel(
            name='Trade',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('date', models.DateTimeField(default=datetime.datetime.now)),
            ],
        ),
    ]

为什么迁移中缺少 2 个外键字段？

Answer 1

这是由于类中每个字段末尾的逗号而发生的Trade。去掉逗号就可以了。

class Trade(models.Model):
    buyer = models.ForeignKey(Player, on_delete=models.CASCADE, related_name='buyer')
    buyee = models.ForeignKey(Player, on_delete=models.CASCADE, related_name='buyee')
    date = models.DateTimeField(default=datetime.now)