Step 4 – Implementing the model layer
Models describe and store business object data, such as a customer relationship management (CRM) opportunity, sales order, or a partner (customer, supplier, and so on). A model describes a list of fields and can also have specific business logic attached to it.
Model data structure and attached business logic are described with Python code, using an object class derived from an Odoo template class. A model maps to a database table, and the Odoo framework takes care of all the database interactions, both in keeping the database structure in sync with the object and in translating all transactions to database instructions. The framework component responsible for this is the object-relational mapping (ORM) component.
Our application will be used to manage a library, and we need a model for the book catalog.
Creating a data model
Following the Odoo development guidelines, the Python files for models should be placed inside a models...
