Django. many-to-many. How to do a cascading delete from a link table?

Question

Django

Let's admit there are two tables and connecting between them...

How to make that at removal of entity "developer", record from the connecting table was deleted also???
What is the correct way to write this in Django? I understand it does not do this by default?

Answer 1

on_delete=models.CASCADE by default. In essence, manytomanyfield just behind the scenes creates another table with ForeignKey relationships for two tables, but no one forbids you to control this manually. Then be sure to include the through attribute in the ManyToManyField:

class M2M(models.Model):
    developer = models.ForeignKey('Developer', on_delete=models.CASCADE)
    project = models.ForeignKey('Project', on_delete=models.CASCADE)
    
    class Meta:
        db_table = "m2m"