Enterprise Library 学习之--数据访问程序块@慕课网原创_慕课网

Data Access Application Block 其实个人感觉相当于另一个版本的dbHelper

废话不多说，先看下如何使用:

1.引用Microsoft.Practices.EnterpriseLibrary.Data.dll(EL安装目录下的bin中就有)

2.配置web.config

<configSections>
...
<section name="dataConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, Version=4.1.0.0, Culture=neutral"/>
...

这一节是系统自动加上去的，原来后面还有一截PublicKeyToken=....，不过在使用中发现系统总是报错无法加载EL程序集之类，所以到园子里搜索了下，参考前人的解决办法去掉了这一段（可能是发行时版本不一致造成的）

此外还要添加连接字符串

这跟常规的web开发几乎没什么不同，要说明的是<dataConfiguration defaultDatabase="Conn"/>这一节标明了默认情况下使用哪个连接字符串

3.下面可以正式使用了，示例代码:

using System;
using System.Data;
using System.Data.Common;
using Microsoft.Practices.EnterpriseLibrary.Data;

namespace test
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            Database db = DatabaseFactory.CreateDatabase("Conn");

            //查询数据
            //this.Repeater1.DataSource = db.ExecuteReader(CommandType.Text, "Select * from GoGo365");

            //调用存储过程(直接传参数的简单调用)
            //this.Repeater1.DataSource = db.ExecuteReader("up_test", "2");

            //切换数据库
            db = DatabaseFactory.CreateDatabase("Conn2");

            //带输出和返回参数的存储过程调用
            DbCommand cmd = db.GetStoredProcCommand("up_Page2005");
            db.AddInParameter(cmd, "TableName", DbType.String, "T_User");
            db.AddInParameter(cmd, "Fields", DbType.String, "F_NickName");
            db.AddInParameter(cmd, "OrderField", DbType.String, "F_Id");
            db.AddInParameter(cmd, "sqlWhere", DbType.String, "F_Status=1");
            db.AddInParameter(cmd, "PageSize", DbType.Int16, 50);
            db.AddInParameter(cmd, "PageIndex", DbType.Int16, 2);
            db.AddOutParameter(cmd, "TotalPage", DbType.Int16, 4);
            db.AddParameter(cmd, "RecordCount", DbType.Int16, ParameterDirection.ReturnValue, "", DataRowVersion.Default, 0);

            this.Repeater1.DataSource = db.ExecuteReader(cmd);
            this.Repeater1.DataBind();

            Response.Write("输出参数值：" + db.GetParameterValue(cmd, "TotalPage").ToString());
            Response.Write("<br />返回参数值：" + db.GetParameterValue(cmd, "RecordCount").ToString());

            //使用事务
            db = DatabaseFactory.CreateDatabase("Conn");
            using (IDbConnection conn = db.CreateConnection())
            {
                conn.Open();
                IDbTransaction _trans = conn.BeginTransaction();
                try
                {
                    DbCommand _cmd = db.GetSqlStringCommand("Insert Into GoGo365(F_NickName) values(@NickName)");
                    db.AddInParameter(_cmd, "NickName", DbType.String, "AA");
                    db.ExecuteNonQuery(_cmd, _trans as DbTransaction);
                    db.ExecuteNonQuery(_cmd, _trans as DbTransaction);//F_NickName字段上建有唯一索引，故第二次插入同样记录时会报错
                    _trans.Commit();
                }
                catch
                {
                    try
                    {
                        _trans.Rollback();//事务提交失败时，则回滚(是否回滚成功，可查看表中有无AA的记录即可)
                    }
                    catch { }
                }
                finally
                {
                    conn.Close();
                }
            }
        }
    }
}
基本上涉及数据库操作的东东都已经在里面了,更多功能大家自己去体验吧