string sql = "update Teacher set TName = '" + TextBox1.Text + "'," +
            "TSex = '" + DropDownList1.SelectedItem.Text + "'," +
            "Tage = '" + TextBox7.Text + "'," +
            "TPhone = '" + TextBox3.Text + "'," +
            "TMail = '" + TextBox4.Text + "'" +
            "where TId = '" + Session["Id"] + "'";
        DBExec db = new DBExec();
        if (db.ExecGetBoolen(sql))
            Response.Write("<script>alert('修改成功')</script>");
        else
            Response.Write("<script>alert('修改失败')</script>");希望对数据库更新,但就是更新不了~~~为什么啊?