Updating fields in access
Each “reverse” operation described in this section has an immediate effect on the database.
Every addition, creation and deletion is immediately and automatically saved to the database.
The only difference is in the attribute naming: The model that defines the Other object-relational mappers require you to define relationships on both sides.
The Django developers believe this is a violation of the DRY (Don’t Repeat Yourself) principle, so Django only requires you to define the relationship on one end.
These references can then be used in query filters to compare the values of two different fields on the same model instance.
The answer lies in the module inside each application.
The hook that the compiler uses in this case to figure out the type is the record field name.
Later in the chapter, we'll talk about what happens when there is more than one record type in scope with the same field name.
For this reason, it’s particularly important that all the models you’re using be defined in applications listed in Queries involving related objects follow the same rules as queries involving normal value fields.
When specifying the value for a query to match, you may use either an object instance itself, or the primary key value for the object.