Active Record

This is a design pattern we all being using for sometime, sometimes without knowing this is a design pattern.

Martin Fowler describes Active Record as;

An object that wraps a row in a database table or view, encapsulates the database access, and adds domain logic on that data.

Active record is an approach to accessing data in a database. A database table or view is wrapped into a class, thus an object instance is tied to a single row in the table. After creation of an object, a new row is added to the table upon save. Any object loaded gets its information from the database; when an object is updated, the corresponding row in the table is also updated. The wrapper class implements accessor methods or properties for each column in the table or view.

This pattern is commonly used by object persistance tools, and in object-relational mapping. Typically foreign key relationships will be exposed as an object instance of the appropriate type via a property.

1. Castle Project Active Record an open-source Microsoft .NET Implementation
2. Dunn & Churchill Diamond Binding a commercially supported Microsoft .NET Implementation
3. Ruby on Rails contains a Ruby implementation of Active Record.
4. Subsonic Project contains a .NET implementation of Active Record.
5. Akelos PHP Framework contains a PHP version of Rails Active Record.
6. Cake PHP contains a PHP implementation of Active Record.
7. Elixir is a Python implementation of Active Record.
8. Grails contains a Groovy implementation of Active Record.