Update function does not update to SQL database

<pre> protected void gvStudent_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {
            try
            {
                using (SqlConnection conn = new SqlConnection(strConn))
                {
                    conn.Open();
                    string query = "UPDATE Student SET Name=@Name,Photo=@Photo,Course=@Course,EmailAddr=@EmailAddr,Password=@Password,Status=@Status,MentorID=@MentorID WHERE StudentID = @id";
                    SqlCommand cmd = new SqlCommand(query, conn);
                    cmd.Parameters.AddWithValue("@Name", (gvStudent.Rows[e.RowIndex].FindControl("txtName") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@Photo", (gvStudent.Rows[e.RowIndex].FindControl("txtPhoto") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@Course", (gvStudent.Rows[e.RowIndex].FindControl("txtCourse") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@EmailAddr", (gvStudent.Rows[e.RowIndex].FindControl("txtEmail") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@Password", (gvStudent.Rows[e.RowIndex].FindControl("txtPassword") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@Status", (gvStudent.Rows[e.RowIndex].FindControl("txtStatus") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@MentorID", (gvStudent.Rows[e.RowIndex].FindControl("txtMentorID") as TextBox).Text.Trim());
                    cmd.Parameters.AddWithValue("@id", Convert.ToInt32(gvStudent.DataKeys[e.RowIndex].Value.ToString()));
                    cmd.ExecuteNonQuery();
                    gvStudent.EditIndex = -1;
                    getStudentDetails();
                    lblSuccessMessage.Text = "Selected Record Updated";
                    lblErrorMessage.Text = "";
                }
            }
            catch (Exception ex)
            {
                lblSuccessMessage.Text = "";
                lblErrorMessage.Text = ex.Message;
            }
        }