What is a Foreign Key in Django models?

What is a Foreign Key in Django models?

A Foreign Key in Django models is a field that creates a relationship between two models. It allows one model to reference another.

Can you give me an example of how to use a Foreign Key in a Django model?

Sure! For instance, if you have a Book model and an Author model, you can define a Foreign Key in the Book model like this:

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 to the related records when the referenced record is deleted. For example, models.CASCADE means that when an Author is deleted, all related Book records will also be deleted.

Are there other options for the on_delete parameter?

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