django.db.utils.OperationalError:外键不匹配-“；进入“返回气缸”；引用；条目“气缸条目”；

即使在我清除了所有迁移之后，仍出现以下错误。在我稍后删除Cylinderentry模型的主键之前，一切都正常工作，但它仍然显示“django.db.utils.OperationalError:外键不匹配-“Entry_returncylinder”引用“Entry_Cylinderentry”

当我运行py manage.py makemigrations时，它会显示：

You are trying to add a non-nullable field 'id' to cylinderentry without a default; we can't do that (the database needs something to populate existing rows).splays following :

django.db.utils.OperationalError: foreign key mismatch - "Entry_returncylinder" referencing "Entry_cylinderentry"

或者，当我运行py manage.py migrate时，它会显示：

You are trying to add a non-nullable field 'id' to cylinderentry without a default; we can't do that (the database needs something to populate existing rows).splays following :

django.db.utils.OperationalError: foreign key mismatch - "Entry_returncylinder" referencing "Entry_cylinderentry"

以下是所有型号：

from django.db import models
from django.utils import timezone
from django.urls import reverse
# Create your models here.
class CylinderEntry(models.Model):
    stachoice=[
    ('Fill','fill'),
    ('Empty','empty') 
    ]
    substachoice=[
    ('Available','availabe'), 
    
    ]
    cylinderId=models.CharField(max_length=50,unique=True)
    gasName=models.CharField(max_length=200)
    cylinderSize=models.CharField(max_length=30)
    Status=models.CharField(max_length=40,choices=stachoice,default='fill')
    Availability=models.CharField(max_length=40,choices=substachoice,default="available")
    EntryDate=models.DateTimeField(default=timezone.now)

    

    def get_absolute_url(self):
        return reverse('cylinderDetail',args=[(self.id)])

    def __str__(self):
        return self.cylinderId


class IssueCylinder(models.Model):
    cylinder=models.OneToOneField('CylinderEntry',on_delete=models.CASCADE)
    userName=models.CharField(max_length=60)
    issueDate=models.DateTimeField(default=timezone.now)
    
    def save(self,*args,**kwargs):
        if not self.pk:
            CylinderEntry.objects.filter(cylinderId=self.cylinder.cylinderId).update(Availability=('issued'))

        super().save(*args,**kwargs)

    def __str__(self):
        
        return self.userName

class ReturnCylinder(models.Model):
    rechoice=[
    ('fill','Fill'),
    ('empty','Empty') 
    ]
    reav=[
        ('Yes','yes'),
        ('No','no')
    ]
    cylinder=models.ForeignKey('CylinderEntry',on_delete=models.CASCADE)
    user=models.ForeignKey('IssueCylinder',on_delete=models.CASCADE)
    status=models.CharField(max_length=20,choices=rechoice)
    returnDate=models.DateTimeField(default=timezone.now)
    Availability=models.CharField(max_length=5,choices=reav)

    

    def save(self,*args,**kwargs):
        if not self.pk:
            IssueCylinder.objects.get(userName=self.user.userName).delete()
            if self.status=='yes' or self.status=='Yes':
                CylinderEntry.objects.get(cylinderId=self.cylinder.cylinderId).update(Availability=('available'))
            else:
                CylinderEntry.objects.get(cylinderId=self.cylinder.cylinderId).delete()

            

        super().save(*args,**kwargs)
    
    def __str__(self):
        return self.cylinder

---

我不知道我在哪里失踪。救命

查看这篇文章，我认为它可能会有所帮助。感谢您的建议，但它不起作用。正如我在问题中提到的，我曾尝试将主键放在CylinderEntry模型上，后来我将其删除，这就是发生此错误的原因。为了解决这个问题，我只清除了所有旧的迁移（在上一个案例中我没有执行），然后再次运行所有迁移。