对象名 'tb_examResult' 无效

public static void BindDG(GridView dg, string id, string strSql, string Tname)
    {
        SqlConnection conn = DBCon();
        SqlDataAdapter sda = new SqlDataAdapter(strSql, conn);
        DataSet ds = new DataSet();
        sda.Fill(ds, Tname);
        dg.DataSource = ds.Tables[Tname];
        dg.DataKeyNames = new string[] { id };
        dg.DataBind();
    }
红色为错误提示