Handling DB connection errors in Cakephp

The quick and dirty way to do this is to put a condition in the constructor. I say dirty because it creates a conditional config and with the introduction of a bug could leave your production app connected to a dev database.

class DATABASE_CONFIG {

    public $default = array(
        'driver' => 'mysql',
        'persistent' => false,
        'host' => '',
        'login' => '',
        'password' => '',
        'database' => '',
        'prefix' => '',
        'encoding' => 'utf8'
    );

    public $testDB = array(
        'driver' => 'mysql',
        'persistent' => false,
        'host' => '',
        'login' => '',
        'password' => '',
        'database' => '',
        'prefix' => '',
        'encoding' => 'utf8'
    );

    public function __construct()
    {
        if (false !== stripos($_SERVER['HTTP_HOST'], 'test'))
        { // Use the test DB since 'test' is present in the server host
            $this->default = $testDB;
        }
    }
}

To test connection you could put the following in the contructor for app_model.php

public function __construct()
{
    parent::__construct();                

    $db =& ConnectionManager::getDataSource('default');
    if (empty($db->connection))
    {
            echo 'oh noes we werent able to connect';
            exit;
    }
}