<?php
/**
 * 
 *
 */
class Util_Dao_Dsn
{
	
	/**
	 * 获取数据库
	 * 
	 * @param String $dbname 	数据库名称
	 * @param String $readtag    读、写
	 * @return Array
	 **/
	public static function getDbServer($dbname, $readtag = true, $dbType = 'Mysql',$charset='UTF8MB4')
	{
	    $options = array(
			'dbname' => 'pre_'.$dbname, 
			'readtag' => $readtag
		);
		$server = Util_Server::factory('Db', $dbType, $options)->loadBalanceServer();
		if (empty($server))
		{
			throw new Util_Dao_Exception('server config is null ,find: ' . $dbname . ' No such config file ');
		}
		$driver_options = array(
			'driver_options' => array(
				PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES '.$charset, 
				PDO::ATTR_PERSISTENT => false, 
				PDO::ATTR_TIMEOUT => defined('Util_DB_ATTR_TIMEOUT') ? Util_DB_ATTR_TIMEOUT : 30
			
		));
		return array_merge($server, $driver_options);
	}
}