往往一个网站需要同时连接多个数据库，例如 用户中心库、消息库、业务库、审批流程库、论坛等等n多数据库，而且很可能还是多种类型的数据库，所以我们需要有一个灵活的数据库访问组件。下面我们看看通用权限管理系统组件里的数据库访问连接库的用法，例子代码是连接4个数据库的实际例子。
//--------------------------------------------------------------------// All Rights Reserved , Copyright (C) 2011 , Hairihan TECH, Ltd. //--------------------------------------------------------------------using System;using System.Data;namespace DotNet.WebForm.Example{ using DotNet.Utilities; /// /// MultiDatabase /// /// 修改纪录 /// /// 版本：1.0 2013.02.03 JiRiGaLa 创建。 /// /// 版本：1.0 /// /// JiRiGaLa /// 2013.02.03 /// /// public partial class MultiDatabase : System.Web.UI.Page { /// /// 同时多数据库连接的方法。 /// /// 优点： /// 同时可以连接多个数据库 /// private void UseMultiDatabase() { // 当然这个数据库连接也可以从配置文件获取，这里是简单的例子，直接写入数据库连接串了 // 用户中心的数据库连接 BaseSystemInfo.UserCenterDbConnection = "Data Source=localhost;Initial Catalog=UserCenterV37;User Id = sa ; Password = Password@sa;max pool size=50;min pool size=10"; // 业务数据库连接 BaseSystemInfo.BusinessDbConnection = "Data Source=localhost;Initial Catalog=ProjectV37;User Id = sa ; Password = Password@sa;max pool size=50;min pool size=10"; // 审批流程数据库连接 BaseSystemInfo.WorkFlowDbConnection = "Data Source=localhost;Initial Catalog=WorkFlowV37;User Id = sa ; Password = Password@sa;max pool size=50;min pool size=10"; // 消息中心数据库连接 BaseSystemInfo.MessageDbConnection = "Data Source=localhost;Initial Catalog=MessageCenterV37;User Id = sa ; Password = Password@sa;max pool size=50;min pool size=10"; // 用户中心的数据库连接 IDataReader dataReader1 = DbHelper.ExecuteReader(BaseSystemInfo.UserCenterDbConnection, "SELECT Id FROM BaseUser"); while (dataReader1.Read()) { } dataReader1.Close(); DbHelper.ExecuteNonQuery(BaseSystemInfo.UserCenterDbConnection, "SELECT COUNT(1) FROM BaseUser"); DbHelper.Fill(BaseSystemInfo.UserCenterDbConnection, "SELECT Id FROM BaseUser"); DbHelper.ExecuteScalar(BaseSystemInfo.UserCenterDbConnection, "SELECT COUNT(1) FROM BaseUser"); // 业务数据库连接 IDataReader dataReader2 = DbHelper.ExecuteReader(BaseSystemInfo.BusinessDbConnection, "SELECT Id FROM Project"); while (dataReader2.Read()) { } dataReader2.Close(); DbHelper.ExecuteNonQuery(BaseSystemInfo.BusinessDbConnection, "SELECT COUNT(1) FROM Project"); DbHelper.Fill(BaseSystemInfo.BusinessDbConnection, "SELECT Id FROM Project"); DbHelper.ExecuteScalar(BaseSystemInfo.BusinessDbConnection, "SELECT COUNT(1) FROM Project"); // 审批流程数据库连接 IDataReader dataReader3 = DbHelper.ExecuteReader(BaseSystemInfo.WorkFlowDbConnection, "SELECT Id FROM BaseWorkFlowProcess"); while (dataReader3.Read()) { } dataReader3.Close(); DbHelper.ExecuteNonQuery(BaseSystemInfo.WorkFlowDbConnection, "SELECT COUNT(1) FROM BaseWorkFlowProcess"); DbHelper.Fill(BaseSystemInfo.WorkFlowDbConnection, "SELECT Id FROM BaseWorkFlowProcess"); DbHelper.ExecuteScalar(BaseSystemInfo.WorkFlowDbConnection, "SELECT COUNT(1) FROM BaseWorkFlowProcess"); // 消息中心数据库连接 IDataReader dataReader4 = DbHelper.ExecuteReader(BaseSystemInfo.MessageDbConnection, "SELECT Id FROM BaseMessage"); while (dataReader4.Read()) { } dataReader4.Close(); DbHelper.ExecuteNonQuery(BaseSystemInfo.MessageDbConnection, "SELECT COUNT(1) FROM BaseMessage"); DbHelper.Fill(BaseSystemInfo.MessageDbConnection, "SELECT Id FROM BaseMessage"); DbHelper.ExecuteScalar(BaseSystemInfo.MessageDbConnection, "SELECT COUNT(1) FROM BaseMessage"); } protected void Page_Load(object sender, EventArgs e) { // 调用多个数据库连接 UseMultiDatabase(); } }}