IQueryable<NotificationFilterBase> filters = repository.GetUserFilters(userId);

        var query = filters.Select(x =>
            x is AlertNotificationFilter
                ? new
                {
                    Strategies = ((AlertNotificationFilter)x).Strategies.Select(strategy =>
                        strategy == AlertStrategy.DayTrade ? NotificationFilterAlertStrategy.DayTrade :
                        strategy == AlertStrategy.FiveStarTrade ? NotificationFilterAlertStrategy.FiveStarTrade :
                        strategy == AlertStrategy.LongTerm ? NotificationFilterAlertStrategy.LongTerm :
                        NotificationFilterAlertStrategy.Swing
                    ).ToArray()
                } : null).ToArray();