django on delete set default

In Django, the "on_delete" attribute is used to specify the behavior of the foreign key when the referenced object is deleted. The "on_delete" attribute can be set to various options, such as "models.SET_DEFAULT," which sets the foreign key to its default value when the referenced object is deleted. When using "on_delete=models.SET_DEFAULT" in a ForeignKey field, the default value for the field is used to replace the value of the field when the referenced object is deleted. This ensures that the integrity of the database is maintained by providing a default value for the foreign key field when the referenced object is no longer available.