DataReader

Hi,


Here are some differences between DataReader & DataSet

DataSet object	DataReader object
Read/Write access	Read-only access
Supports multiple tables from different databases	Supports a single table based on a single SQL query of one database
Disconnected mode	Connected mode
Bind to multiple controls	Bind to a single control
Forward and backward scanning of data	Forward-only scanning of data
Slower access to data	Faster access to data
Greater overhead to enable additional features	Lightweight object with very little overhead
Supported by Visual Studio .NET tools	Must be manually coded

For more detail :http://msdn.microsoft.com/en-us/magazine/cc188717.aspx

Hi Aamir,

DataReader provides forward-only and read-only access to data , while the DataSet object can hold more than one table (in other words more than one rowset) from the same data source as well as the relationships between them.

Dataset is a disconnected architecture while datareader is connected architecture.

Dataset can persists contents while datareader can not persist contents , they are forward only.


Dataset Datareader example to display record in gridview.

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>





   


   

   

   
   

   
   
            Text="Using Dataset" />
            Text="Using Datatable" />
            Text="Using Datareader" />
   




using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.OleDb;
public partial class _Default : System.Web.UI.Page
{
    OleDbConnection con;
    OleDbCommand com;
    OleDbDataAdapter oda;
    DataSet ds;
    DataTable dataTable;
  
    protected void Button1_Click(object sender, EventArgs e)
    {
        con = new OleDbConnection("Provider = Microsoft.Jet.OLEDB.4.0; Data Source = D:\\mydb.mdb");
        com = new OleDbCommand("Select * from emp", con);
        con.Open();
        oda = new OleDbDataAdapter(com);
        ds = new DataSet();
        oda.Fill(ds, "emp");
        con.Close();
        GridView1.DataMember = "emp";
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        con = new OleDbConnection("Provider = Microsoft.Jet.OLEDB.4.0; Data Source = D:\\mydb.mdb");
        dataTable = new DataTable();
        com = new OleDbCommand();
        com.Connection = con;
        con.Open();
        com.CommandText = "Select * from emp";
        oda = new OleDbDataAdapter(com);
        oda.Fill(dataTable);
        con.Close();
        GridView1.DataSource = dataTable;
        GridView1.DataMember = "emp";
        GridView1.DataBind();
    }
    protected void Button3_Click(object sender, EventArgs e)
    {
        con = new OleDbConnection("Provider = Microsoft.Jet.OLEDB.4.0; Data Source = D:\\mydb.mdb");
        com = new OleDbCommand("Select * from emp", con);
        con.Open();
        OleDbDataReader reader;
        reader = com.ExecuteReader();
        GridView1.DataMember = "emp";
        GridView1.DataSource = reader;
        GridView1.DataBind();
        reader.Close();
        con.Close();
    }
}




Thanks
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