count total number if rows in table

    protected void Button2_Click(object sender, EventArgs e)

    {

        cmd = new SqlCommand("select count(id) from std", con);

        con.Open();

        int c = Convert.ToInt32(cmd.ExecuteScalar());//ExecuteScalar is use when you want single value result like number of rows, total of salary average etc.

        Response.Write("total no of records are : " + c);

    }