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Your intermediate model must contain one - and only one - foreign key to the target model (this would be Person in our example). If you have more than one foreign key, a validation error will be raised.
1 Answer. Show activity on this post. In your models Device and History models are related with a foreign key from History to DeviceModel, this mean when you have a History object you can retrieve the Device model related to it, and viceversa (if you have a Device you can get its History).
The only difference between these two is that ForeignKey field consists of on_delete option along with a model's class because it's used for many-to-one relationships while on the other hand, the OneToOneField, only carries out a one-to-one relationship and requires only the model's class.
ForeignKey is a Django ORM field-to-column mapping for creating and working with relationships between tables in relational databases.
Let's say I have the following:
class Employee(models.Model): firstName = models.CharField(max_length = 30) lastName = models.CharField(max_length = 30) class License(models.Model): employee = models.ForeignKey(Employee) type = models.CharField(max_length = 30) and in a custom management command, I'm pulling in all the Employee objects with employees = Employee.objects.all()... how can I access associated License objects for each employee object? I have seen questions that talk about using ContentType for this purpose, but I'm confused on it's practical use. Can anyone provide an example on how to use ContentType (or another solution) in this context?
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