Django Notes 7: Relational Database Handling

Many-to-One Relationship

In order to perform relation between different models, we can define the field by the following:

customer = models.ForeignKey(Customer, null=True, on_delete=models.SET_NULL)

The on_delete parameter states that the whole instance will be deleted automatically when the customer is deleted.

Many-to-Many Relationship

For the many-to-many relationship, we can define the field by the following:

tags = models.ManyToManyField(Tag)

Then we can store multiple values for a corresponding type of object.