Question

这是我的型号代码

class Poll(models.Model):
    created_at = models.DateTimeField(auto_now=True)
    edited_at = models.DateTimeField(auto_now_add=True)
    title = models.CharField(max_length=200,default="X vs Y")
    description = models.CharField(max_length=200,default="A poll")
    def __str__(self):
        return self.title



class Item(models.Model):
    poll = models.ForeignKey('Poll',on_delete=models.CASCADE)
    created_at = models.DateTimeField(auto_now=True)
    edited_at = models.DateTimeField(auto_now_add=True)
    name = models.CharField(max_length=200)
    type_of = models.CharField(max_length=200)
    description = models.TextField(max_length=1200)
    votes = models.IntegerField(default=0)
    def __str__(self):
        return self.name

您可以在项目模型中看到投票权。那是个问题。我使用makemigrations migrate命令。但我仍然没有得到这样的列错误。

编辑：这是makemigrations vs_chart输出

Migrations for 'vs_chart':
  vs_chart\migrations\0001_initial.py:
    - Create model Item
    - Create model Poll
    - Add field poll to item

这是migrate命令输出。

Operations to perform:
  Apply all migrations: vs_chart
Running migrations:
  No migrations to apply.

Answer 1

在向项目添加字段轮询之前，您可能会尝试为ForeignKey提供默认值，缺少默认值可能会导致此问题：

poll = models.ForeignKey('Poll',on_delete=models.CASCADE, default=0)

即使在迁移之后，Django也没有这样的专栏

1 个答案: