First add a Image button to your application and pass the url of Image in it like this:
<asp:ImageButton Width="200px" Height="50px" ID="img" ImageUrl="~/Anubhav Chaudhary.jpg" runat="server" OnClick="img_Click" />
Now go to your aspx.cs file and writ on the click of this Image button like this:
protected void img_Click(object sender, ImageClickEventArgs e)
{
}
As you had done the coding on normal button, similar coding will be done here also. Firstly add Namespace for SQL/Oracle/Access/Excel etc. now add the Connection, Command, Adaptar, reader or whatever you need and just provide the coding in the click of this Image button.