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Chapter 3
In addition to that, each Model type is formed by the following layers:
• Model class: Here is where most of our business logic resides. Models are
used to manipulate the data, but they don't access it directly.
• Resource Model class: Resource Models are used to interact with
the database on behalf of our models. They are in charge of the actual
CRUD operations.
• Model Collection class: Each Data Model has a collection class; collections
are objects that hold a number of individual Magento Model instances.
CRUD stands for the four basic types of database operations:
create, read, update, and delete.
Magento Models don't contain any logic for communicating with the database; they
are database agnostic. Instead, this code resides in the Resource Model layer.
This gives Magento the capacity to support different types of databases and
platforms. Although currently only MySQL is officially supported, it is entirely
possible to write a new resource class for a new database without touching any
of the Model logic ones.
Model Layer
Model
Resource Layer
Resource Model
Adapter Layer
Database adapter
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