magento 切换数据库，使用不同数据库

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