Enterprise Library 4.1学习笔记2----数据访问程序块

简介: 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 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

<connectionStrings>
 <add name="Conn" connectionString="Data Source=.;Initial Catalog=Six;Persist Security Info=True;User ID=sa;Password=***" providerName="System.Data.SqlClient"/>
 <add name="Conn2" connectionString="Data Source=.;Initial Catalog=dbUser;Persist Security Info=True;User ID=sa;Password=***" providerName="System.Data.SqlClient"/>
</connectionStrings>
<dataConfiguration defaultDatabase="Conn"/>

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
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