drpdown list fill using query

 
  SqlCommand cmd = new SqlCommand("select * from user_login where groupid=1", cnn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            ddlstudentname.DataSource=ds;
            ddlstudentname.DataTextField="name";
            ddlstudentname.DataVlaueField="name";
            ddlstudentname.DataBind();