Enterprise Library 4.1学习笔记2----数据访问程序块
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.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();
}
}
}
}
}