July 7, 2021

Programmingempire

Although, there are many ways to create a DataTable object, in this article I will explain Creating a DataTable from a DataReader object. To begin with, first I will explain the DataReader object in brief.

DataReader in ADO.NET

Basically, a DataReader object in ADO.NET represents the connected approach of data access. A DataReader object provides read-only and forward-only access to data. Hence, the data access using DataReader is sequential. In other words, it is not possible to access any record randomly with DataReader.

DataTable in ADO.NET

Another class available in the ADO.NET library is DataTable that represents an in-memory table of data. Since we have this object in the application’s memory, it is possible to retrieve records in any order. Hence, we can use DataTable to get non-sequential access to data. furthermore, it is possible to bind the DataTable object to a Data Bound control in, ASP.NET such as GridView.

Load() Method of DataTable

As can be seen in the following code, we use the Load() method to fill the data values retrieved from a data source using an implementation of the IDataReader interface. In fact, the SqlDataReader class inherits from the abstract class DbDataRedaer. Further, the DbDataReader class implements the IDataRedaer interface. Hence, we can pass the object of SqlDataReader class as a parameter to the Load() method.

Example of Creating a DataTable from a DataReader

As an illustration, the WebForm just contains a GridView control.

WebForm1.aspx.cs

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="DataTableExample.WebForm1" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:GridView ID="GridView1" runat="server"></asp:GridView>
        </div>
     </form>
</body>
</html>

WebForm1.aspx.cs

The following code shows how to access data from a database table using a connected approach. As a result of executing the select command of SQL, a DataReader object is returned. Later, we use this object to fill the DataTable object using the Load() method. Finally, the data binding is performed that loads the DataTable in GridView control.

using System;
using System.Data;
using System.Data.SqlClient;

namespace DataTableExample
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        SqlConnection c1;
        SqlCommand cmd;
        SqlDataReader dr;
        DataTable dt;
        public void Connect()
        {
            c1 = new SqlConnection(@"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=C:UsersKAVITADocumentsd1.mdf;Integrated Security=True;Connect Timeout=30");
            c1.Open();
        }
        public void CreateTable()
        {
            Connect();
            cmd = new SqlCommand("select * from Items", c1);
            dr = cmd.ExecuteReader();
            dt = new DataTable();
            dt.Load(dr);
        }
        protected void Page_Load(object sender, EventArgs e)
        {
            CreateTable();
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }
    }
}

Output

**An Example to Demonstrate Creating a DataTable from a DataReader**

Creating a DataTable from a DataReader in ASP.NET

Programmingempire

DataReader in ADO.NET

DataTable in ADO.NET

Load() Method of DataTable

Example of Creating a DataTable from a DataReader

Further Reading

Programmingempire

DataReader in ADO.NET

DataTable in ADO.NET

Load() Method of DataTable

Example of Creating a DataTable from a DataReader

Further Reading

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