asp.net 多数据库支持的思考

<connectionstrings>
<add name="mycmsconnectionstring" connectionstring="server=(local);user id=sa;pwd=123456;database=mycms;"/>
</connectionstrings>

using system;
using system.collections.generic;
using system.text;
using system.configuration;
using system.data;
using system.data.common;
namespace common
{
public class class1
{
public dbconnection getdatabaseconnection()
{
connectionstringsettings settings = configurationmanager.connectionstrings["conn"];
dbproviderfactory factory = dbproviderfactories.getfactory(settings.providername);
dbconnection conn = factory.createconnection();
conn.connectionstring = settings.connectionstring;
return conn;
}
}
}