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();
}
}
}
}
}
出处:http://yjmyzz.cnblogs.com
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