
Odoo 14 Development Cookbook
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Hierarchies are represented like a model having relations with the same model. Each record has a parent record in the same model, and many child records. This can be achieved by simply using many-to-one relations between the model and itself.
However, Odoo also provides improved support for this type of field by using the nested set model (https://en.wikipedia.org/wiki/Nested_set_model). When activated, queries using the child_of
operator in their domain filters will run significantly faster.
Staying with the Library Books
example, we will build a hierarchical category tree that can be used to categorize books.
We will continue using the my_library
add-on module from the previous recipe.
We will add a new Python file, models/library_book_categ.py
, for the category tree, as follows:
models/__init__.py
:from . import library_book_categ