How to connect to two databases simutaneously ¶

Add these lines in /config/main.php

'components'=>array(
.........
		'db'=>array(
			'connectionString' => 'mysql:host=localhost;dbname=database1',
			'emulatePrepare' => true,
			'username' => 'root',
			'password' => 'itsasecret',
			'charset' => 'utf8',
		),
		'db2'=>array(
		    'class' => 'CDbConnection',
			'connectionString' => 'mysql:host=localhost;dbname=database2',
			'emulatePrepare' => true,
			'username' => 'root',
			'password' => 'itsasecret',
			'charset' => 'utf8',
		),
....
),

Create a new file in protected/components, this example is called AltActiveRecord.php ¶

abstract class AltActiveRecord extends CActiveRecord
{
	const BELONGS_TO='CBelongsToRelation';
	const HAS_ONE='CHasOneRelation';
	const HAS_MANY='CHasManyRelation';
	const MANY_MANY='CManyManyRelation';
	const STAT='CStatRelation';

	/**
	 * @var CDbConnection the default database connection for all active record classes.
	 * By default, this is the 'db' application component.
	 * @see getDbConnection
	 */
	public static $db;

	private static $_models=array();			// class name => model

	private $_md;								// meta data
	private $_new=false;						// whether this instance is new or not
	private $_attributes=array();				// attribute name => attribute value
	private $_related=array();					// attribute name => related objects
	private $_c;								// query criteria (used by finder only)
	private $_pk;								// old primary key value

	/**
	 * Returns the database connection used by active record.
	 * By default, the "db" application component is used as the database connection.
	 * You may override this method if you want to use a different database connection.
	 * @return CDbConnection the database connection used by active record.
	 */
	public function getDbConnection()
	{
		if(self::$db!==null)
			return self::$db;
		else
		{
		
			// Create CDbConnection and set properties
			self::$db = new CDbConnection();
			foreach(Yii::app()->db2 as $key => $value)
				self::$db->$key = $value;
		
		
		// Uncomment the following lines to prove that you have two database connections
		/*
			CVarDumper::dump(Yii::app()->db);
			echo '<br />';
			CVarDumper::dump(Yii::app()->db2);
	        die;
        */
			if(self::$db instanceof CDbConnection)
			{
				self::$db->setActive(true);
				return self::$db;
			}
			else
				throw new CDbException(Yii::t('yii','Active Record requires a "db" CDbConnection application component.'));
		}
	}
}

For each model using the second database,extend the above file example; ¶

/**
 * This is the model class for table "pagedata".
 */
class Pagedata extends AltActiveRecord
{
..
// model stuff here
..
}

Your application should now have access to two databases simultaneously. ¶

Multiple Domains with one entry script

Now for multiple sites (multiple domains) using one installation of Yii and one entry script, example parked domains.

// change the following paths if necessary
$hostname = $_SERVER['SERVER_NAME'];
$yii=dirname(__FILE__).'/../../framework/yii.php';

switch ( strtolower($hostname))
{
case 'example1.com';
case 'www.example1.com';
    $config=dirname(__FILE__).'/protected/config/main.php';
    // database 1
break;
case 'example2.com';
case 'www.example2.com';
    $config=dirname(__FILE__).'/protected/config/main2.php';
    // database 2
break;

case 'example3.com';
case 'www.example3.com';
    $config=dirname(__FILE__).'/protected/config/useAnyName.php';
    // database 3 
break;

default:
$config=dirname(__FILE__).'/protected/config/main.php';
}
// remove the following lines when in production mode
defined('YII_DEBUG') or define('YII_DEBUG',true);
defined('YII_TRACE_LEVEL') or define('YII_TRACE_LEVEL',3);

require_once($yii);
Yii::createWebApplication($config)->run();

In each config file you can specify numerous parameters that are site specific. ¶

// application-level parameters that can be accessed
	// using Yii::app()->params['paramName']
	'params'=>array(
		// this is used in contact page
		'adminEmail'=>'admin@example1.com',
		'googleCode'=>'UA-2****8-11',
		'juitheme'=>'dark-hive',
		'cssfile'=>'cwdi'
	),

For example styling could be set for each domain name like this (in layout.php)

<link rel="stylesheet" type="text/css" href="<?php echo Yii::app()->request->baseUrl; ?>/css/<?php echo Yii::app()->params->cssfile; ?>.css" />

I hope this helps someone

doodle