Cross Database foreign key error

This my model of first Database DB1:

     from django.db import models 

     class Company(models.Model): 

          name = models.CharField(max_length=100, null=True)
          address = models.TextField(max_length=200, null=True)
          website = models.CharField(max_length=200, null=True)
          conatct_no = models.CharField(max_length=20, null=True)
          email = models.EmailField(max_length=20, null=True)
          logo = models.FileField(upload_to='logo/', blank=True, null=True)
          created = models.DateTimeField('company created', auto_now_add=True)
          updated = models.DateTimeField('company updated', auto_now=True, null=True)
          def __unicode__(self):  # Python 3: def __str__(self):
                return self.name

Model of 2nd Database Db2:

    from django.db import models

    from leavebuddymaster.models import Company

    class Department(models.Model): 
       company = models.ForeignKey(Company)
       department_name = models.CharField(max_length=50, null=True)
       created = models.DateTimeField('department created', auto_now_add=True)
       updated = models.DateTimeField('department updated', auto_now=True, null=True)
       def __unicode__(self):  # Python 3: def __str__(self):
            return self.department_name

Now when i open the Department table it gives me a error as:

      ProgrammingError at /admin/leavebuddyapp/department/
      (1146, "Table 'leavebuddy_master.leavebuddyapp_department' doesn't exist")

I have done all the settings in settings.py correctly for the two databases. Can you please guide me in the right direction. Thanx in advance.

Solution

You're correct, Django does not currently support foreign key relationships spanning multiple databases. From Cross-database relations [Edit 2020: Django version bump]:

If you have used a router to partition models to different databases, any foreign key and many-to-many relationships defined by those models must be internal to a single database.

This is because of referential integrity. In order to maintain a relationship between two objects, Django needs to know that the primary key of the related object is valid. If the primary key is stored on a separate database, it’s not possible to easily evaluate the validity of a primary key.

A solution I thought up that you could try (though it may present other problems):

from leavebuddymaster.models import Company

class Department(models.Model): 
    company_id = models.IntegerField()
    
    @property
    def company(self):
        return Company.objects.get(pk=self.company_id)

This allows you to refer to Department.company like you normally would in your example. Setting it would just be a matter of Department.company_id = Company.pk. Hope it helps, or at least inspires a better solution!