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));
I want to sum Column "Fee" which is nvarchar type and group it by MonthID
Just look to this example
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)));
The keys are identifiers of months and values - sums of fee for appropriate month.