Kim Majali

OneToOne Relationship

Kim Majali wrote on 08/06/2022

Create

class Place(models.Model):
    name = models.CharField(max_length=50)

class Restaurant(models.Model):
    place = models.OneToOneField(Place, on_delete=models.CASCADE, primary_key=True)
    serves_pizza = models.BooleanField(default=False)

OneToMany Relationship

Kim Majali wrote on 08/06/2022

To define a many-to-one relationship, use ForeignKey:

If a model has a ForeignKey, instances of that model will have access to the related (foreign) object via an attribute of the model.

Circular Import Problem Between Apps

Kim Majali wrote on 08/06/2022

ImportError: cannot import name 'Customer' from partially initialized module 'translation.models' (most likely due to a circular import)

To use in model fields

Instead of import from another app link to it directly App.Model

Django Model’s Methods

Kim Majali wrote on 08/06/2022

FAT models THIN view

1. Can be called from any where by selecting the object (No need to repeat)

2.Can be accessed on templates if they return value (No need to pass to the context)

Django Signals

Kim Majali wrote on 08/06/2022

Signals allow certain senders to notify a set of receivers that some action has taken place so they continue

List is here https://docs.djangoproject.com/en/4.0/ref/signals/