introduction-to-model.md

Non-Relational Models > Introduction to Model

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Base Class for your Real-Life entities. For use with no-SQL Data Controllers. Implements active record. Compatible with most Views.

$book = $this->add('Model_Book')
  ->setSource('MemCached','book')
  ->load($_GET['id']);
$book['views']++;
$book->save();

Model is a fundamental class in Agile Toolkit which introduces concept of a very basic Active Record mechanism. Models also hold meta-information about your entity fields such as types, captions, validation, etc

Depending on the requirement you can choose from 3 parent classes: Model_Table, Model or AbstractModel:

• Model_Table is the most commonly used and offers powerful ORM features for working with relational databases
• Model provides a pluggable interface to NoSQL data storage, Arrays and Sessions
• AbstractModel is a minimal Model used to develop alternative implementations.

GOALS AND FEATURES OF MODEL

• Hierarchical Business Model - Objects in our life are hierarchical. Your database is not. Agile Toolkit models follow your business model and adapt your data-base.
• Field Object - Each field is defined through a "Field" object. Need more meta-information, properties or flexibility? Extend the Field class.
• Database, Table, ID - Models assume that controller is using one database at a time. Inside a database you may have multiple tables (or files). Inside each file you will have records identified by "ID" (or key).
• Allow do modify existing Model - After you create instance of a model, you can define few more fields if you need to.
• Multiple Data Controllers - You may load model through one Data Controller, save will use same controller by default. You can, however, use another controller with same model.
• Great Syntax - Models implement iterators and array access. That means you can access model properties as it would be array and you can traverse through records inside a foreach() loop.
• Field names are unique - You can't have multiple fields with the same name.
• Use in View or directly - Models are great for either direct use or to be used by standard views. Some other controllers will accept models too.
• Hooks - Models use hooks allowing you to control loading / saving events.

WHAT DSQL IS NOT?

In the spirit of Agile Toolkit — all of it's classes are strictly focused on a one simple task, without trying to do everything. Here are things which Model will not do and why:

• No code generation - Model is implemented in under 200 lines of PHP code. It is designed to be common lowest denominator for many views.
• No Relations, Dependencies, Conditions or Expressions - Model is designed to be simple. It does not support RDBMS features.
• No emulation of SQL - Model does not attempt to emulate SQL features such as offsets. That's job of a Controller to implement.