想明智地查詢月費

Question

var TotalFee = (from item in _dbEntities.MonthlyFees
                               where item.Year == DateTime.Now.Year &&
                               item.FeeStatus == true
                               select item).GroupBy(x =>x.MonthID);//.AsEnumerable().Sum(x => int.Parse(x));

我想總結列“費用”，它是nvarchar類型，並按MonthID分組

Answer 1

請看這個例子

var feesDictionary = _dbEntities.MonthlyFees
            .Where(x => x.Year.Equals(DateTime.Now.Year) && x.FeeStatus)
            .GroupBy(x => x.MonthID)
            .ToDictionary(x => x.Key, x => x.Sum(y => Convert.ToDouble(y.Fee)));

密鑰是月份和值的標識符 - 適當月份的費用總和。