Getting data from a database

Most applications today use databases. Be it a small website or a social network, at least some parts are powered by databases. Yii introduces three ways that allow you to work with databases:

• Active Record

• Query builder

• SQL via DAO

We will use all these methods to get data from the film, film_actor, and actor tables and show it in a list. We will measure the execution time and memory usage to determine when to use these methods.

Getting ready

1. Create a new application by using yiic webapp as described in the official guide at the following URL:

   http://www.yiiframework.com/doc/guide/en/quickstart.first-app

2. Download the Sakila database from the following URL:

   http://dev.mysql.com/doc/index-other.html

3. Execute the downloaded SQLs; first schema then data.

4. Configure the DB connection in protected/config/main.php to use the Sakila database.

5. Use Gii to create models for the actor and film tables.

How to do it...

1. We will create protected/controllers/DbController.php as follows...