Step 1:
Database
I created a database called mysql and saved it in the same folder which have table called sqltest with fields.

Step 2:
Drag the grid view from the toolbox
Step 3:
now on the Default.aspx.cs or whatever you given the name of form write this coding
using System;
using System.Data;
/* Please remember to import SqlClient namespace */
using System.Data.SqlClient;
public partial class GridView_Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
/* Check whether the page is post back or not */
if (!Page.IsPostBack)
{
BindData();
}
}
private void BindData()
{
SqlConnection con= new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|mysql.mdf;Integrated Security=True;User Instance=True");
SqlDataAdapter ad = new SqlDataAdapter("select * from sqltest",con);
DataSet ds = new DataSet();
ad.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}
}
The Output is :