What are foreign keys in Django models?

What are foreign keys in Django models?

Foreign keys in Django models are used to create a relationship between two models. They allow you to link one model to another.

Can you give me an example of how to define a foreign key in a Django model?

Sure! You can define a foreign key in a Django model using the ForeignKey field. For example:

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

What does the on_delete parameter do?

The on_delete parameter specifies what should happen when the referenced object is deleted. For example, models.CASCADE will delete all related books if the author is deleted.

Are there other options for the on_delete parameter?

Yes, there are several options like SET_NULL, PROTECT, and SET_DEFAULT, each defining different behaviors when the referenced object is deleted.