python - 迁移: "There is no unique constraint matching given keys for referenced table的django错误

因此，我看到很多这类问题突然出现(很少回答)，而在我所看到的Django方面却没有一个。我很困惑为什么我得到错误，我想我在字段装饰器上缺少了某些东西，或者在模型定义中没有了。这是两个模型...(一个缩写)。我以为我在外键引用的一个表中将唯一键和主键设置为true，就可以正确地做所有事情，但是在迁移时会出现此错误:
django.db.utils.ProgrammingError: there is no unique constraint matching given keys for referenced table "swsite_zoneentity"
编辑过时的代码...

class ZoneEntity(models.Model):
    zone_number = models.CharField(max_length=100, primary_key=True)
    mpoly = models.PolygonField() #this should grow and shrink for the most representative one...
    objects = models.GeoManager()
    created_at=models.DateField(auto_now_add=True)
    updated_at=models.DateField(auto_now=True)

class CesiumEntity(models.Model):
    be_number = models.CharField(max_length=100) #the number assigned to a foot print to distinguish
    #zone_id = models.CharField(max_length=100, null=True, blank=True)
    zone_id = models.ForeignKey('ZoneEntity', null=True, blank=True)

最佳答案

Codejoy，

定义主键时，它会自动设置为唯一键。因此，只需执行以下操作:

class ZoneEntity(models.Model):
    zone_number = models.CharField(max_length=100, primary_key=True)
    ....

class CesiumEntity(models.Model):
    ...
    zone_id = models.ForeignKey('ZoneEntity', null=True, blank=True)
    ...

这将自动将ZoneEntity的PK与zone_id绑定(bind)!

如果您尝试建立关系的字段不是主键，则可以添加unique=True和to_field='foo'

 - python manage.py. makemigration
s
Migrations for 'module1':
  0002_auto_20170214_1503.py:
    - Create model CesiumEntity
    - Create model ZoneEntity
    - Add field zone_id to cesiumentity

 - python manage.py migrate
Operations to perform:
  Synchronize unmigrated apps: staticfiles, messages
  Apply all migrations: admin, contenttypes, module1, auth, sessions
Synchronizing apps without migrations:
  Creating tables...
    Running deferred SQL...
  Installing custom SQL...
Running migrations:
  Rendering model states... DONE
  Applying module1.0002_auto_20170214_1503... OK

关于python - 迁移: "There is no unique constraint matching given keys for referenced table的django错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42234330/