How do I define relationships between models in Django ORM?

How do I define relationships between models in Django ORM?

In Django ORM, you can define relationships using fields like ForeignKey, OneToOneField, and ManyToManyField.

Can you give me an example of a ForeignKey relationship?

Sure! If you have a Book model and an Author model, you can define a ForeignKey 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=models.CASCADE mean?

on_delete=models.CASCADE means that when the referenced Author is deleted, all related Book instances will also be deleted.

How can I create a ManyToMany relationship?

You can create a ManyToMany relationship by using the ManyToManyField. For example:

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

class Course(models.Model):
    title = models.CharField(max_length=200)
    students = models.ManyToManyField(Student)