1. 在app/etc/local.xml 中，添加新的数据库选项

<?xml version="1.0"?>  
    <config>  
        <global>  
            <install>  
                <date><![CDATA[Tue, 05 Jul 2011 03:23:52 +0000]]></date>  
            </install>  
            <crypt>  
                <key><![CDATA[80eb4be66ce28df745f27c75f2604d33]]></key>  
            </crypt>  
            <disable_local_modules>false</disable_local_modules>  
            <resources>  
                <db>  
                    <table_prefix><![CDATA[]]></table_prefix>  
                </db>  
                <default_setup>  
                    <connection>  
                        <host><![CDATA[localhost]]></host>  
                        <username><![CDATA[root]]></username>  
                        <password><![CDATA[]]></password>  
                        <dbname><![CDATA[hello]]></dbname>  
                        <active>1</active>  
                    </connection>  
                </default_setup>  
      
                <vip_space_read>  
                    <connection>  
                        <host><![CDATA[localhost]]></host>  
                        <username><![CDATA[root]]></username>  
                        <password><![CDATA[]]></password>  
                        <dbname><![CDATA[hello_dev_test]]></dbname>  
                        <model>mysql4</model>  
                        <initStatements>SET NAMES utf8</initStatements>  
                        <type>pdo_mysql</type>  
                        <active>1</active>  
                    </connection>  
                </vip_space_read>  
            </resources>  
            <session_save><![CDATA[files]]></session_save>  
        </global>  
        <admin>  
            <routers>  
                <adminhtml>  
                    <args>  
                        <frontName><![CDATA[hello_admin]]></frontName>  
                    </args>  
                </adminhtml>  
            </routers>  
        </admin>  
    </config>  

2. 在需要使用的不同数据库的model resource中，重写 _setResource 方法，例如

  class Hello_Vip_Model_Entity_Vip_Adapter extends Mage_Core_Model_Mysql4_Abstract  
    {  
        protected $_logFile = 'vip.adapter.log';  
      
        protected function _construct()  
        {  
            $this->_setResource(array('read' =>'vip_space_read', 'write'

=>'vip_space_read'));  
        }  

经过以上两步，就能在某个model中使用不同的数据库