C# ASP.NET 通用权限管理系统组件的数据访问层的调用方法参考2 - 多种类型的多数据库连接方法

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;
    
    /// <remarks>
    /// MultiDatabase
    /// 
    /// 修改纪录
    /// 
    ///        版本：1.0 2013.02.03    JiRiGaLa    创建。
    ///    
    /// 版本：1.0
    /// <author>
    ///        <name>JiRiGaLa</name>
    ///        <date>2013.02.03</date>
    /// </author> 
    /// </remarks>
    public partial class MultiDatabase : System.Web.UI.Page
    {
        /// <summary>
        ///  同时多数据库连接的方法。
        ///     
        ///     优点：
        ///     同时可以连接多个数据库
        /// </summary>
        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();
        }
    }
}