Yii has a special class named CClientScript that can help include scripts, CSS, and other resources in the page.
In order to include an external JS , you can use the following code:
Yii::app()->clientScript-> registerScriptFile('http://example.com/js/main.js);

The name of configuration file is main.php and it is located in protected/config/main.

The name of configuration file is main.php and it is located in protected/config/main.

We can active MySql database driver in YII by this way:
'connectionString' => 'mysql:host=localhost;dbname=yii_sir',
'username' => 'root',
'password' => '',
and we have to work on  protected/config/ database.php

We can import custom classes in YII by following way:
<?php Yii::import(“application.Something.Animal/MountDuck”); ?>