public QueryModel Alter(string filterField = null, string filterValue = null, string filterOper = null, string orderBy = null, int orderDir = 0, int take = 0, int skip = -1)
        {
            var newQueryModel = new QueryModel(FilterField, FilterValue, FilterOper, OrderBy, OrderDir, Take, Skip);
            if (!String.IsNullOrEmpty(filterField))
            {
                newQueryModel.FilterField = filterField;
            }
            if (!String.IsNullOrEmpty(filterValue))
            {
                newQueryModel.FilterValue = filterValue;
            }
            if (!String.IsNullOrEmpty(filterOper))
            {
                newQueryModel.FilterOper = filterOper;
            }
            if (!String.IsNullOrEmpty(orderBy))
            {
                newQueryModel.OrderBy = orderBy;
            }
            if (orderDir != 0)
            {
                newQueryModel.OrderDir = orderDir;
            }
            if (take != 0)
            {
                newQueryModel.Take = take;
            }
            if (skip > -1)
            {
                newQueryModel.Skip = skip;
            }

            return newQueryModel;
        }
 public ListResult(int allCount, QueryModel queryModel)
 {
     AllCount = allCount;
     QueryModel = queryModel;
 }