In this article I will explain with an example, how to fetch (retrieve) data from database using DataTable in Windows Forms (WinForms) Application using C# and VB.Net.
 
 

Database

Here I am making use of Microsoft’s Northwind Database. You can download it from here.
Download and install Northwind Database
 
 

Form Design

The following form consists of:
DataGridView – For displaying data.
Fetch (Retrieve) data from Database using DataTable with C# and VB.Net
 
 

Namespaces

You will need to import the following namespaces.
C#
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
 
VB.Net
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
 
 

Binding data to DataGridView from Database using DataTable

Inside the Form Load event handler, first the connection is read from App.Config file.
Note: For more details on how to read connection string from App.Config, file please refer my article .Net 4.5: Read (Get) Connection String from App.Config file using C# and VB.Net.
 
Then, the records are fetched from the Customers Table of Northwind database.
Finally, DataTable is assigned to the DataSource property of DataGridView.
C#
private void Form1_Load(object sender, EventArgs e)
{
    string sql = "SELECT * FROM Customers";
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter(sql, con))
        {
            using (DataTable dt = new DataTable())
            {
                sda.Fill(dt);
                dgvCustomers.DataSource = dt;
            }
        }
    }
}
 
VB.Net
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim sql As String = "SELECT * FROM Customers"
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(constr)
        Using sda As SqlDataAdapter = New SqlDataAdapter(sql, con)
            Using dt As DataTable = New DataTable()
                sda.Fill(dt)
                dgvCustomers.DataSource = dt
            End Using
        End Using
    End Using
End Sub
 
 

Screenshot

Fetch (Retrieve) data from Database using DataTable with C# and VB.Net
 
 

Downloads

Download Code