public ErrorData Delete(Context context, SiteSettings ss, bool notice = false)
        {
            var statements = new List <SqlStatement>();

            var where = Rds.RegistrationsWhere().RegistrationId(RegistrationId);
            statements.AddRange(new List <SqlStatement>
            {
                Rds.DeleteRegistrations(where : where),
            });
            Rds.ExecuteNonQuery(
                context: context,
                transactional: true,
                statements: statements.ToArray());
            return(new ErrorData(type: Error.Types.None));
        }