[Solved]-How select rows with grouping by month-LINQ,C#

we can do this by using linq. please find the below code snippet in c#. hope it helps. here we are grouping by year and month and then summing up the amount as well.

namespace solutions
{
    using system;
    using system.collections.generic;
    using system.linq;

    public class security
    {
        public guid id { get; set; }

        public string name { get; set; }

        public string quatation { get; set; }

        //public securitytype securitytype { get; set; }

        public double denomination { get; set; }

        //public currencytype demoniationtype { get; set; }

        public virtual icollection<reportperiod> reportperiods { get; set; }
    }

    public class reportperiod
    {
        public guid id { get; set; }

        public datetime start { get; set; }

        public datetime end { get; set; }

        public guid securityid { get; set; }

        public guid stockexchangeid { get; set; }

        public double amount { get; set; }

        public virtual security security { get; set; }
    }

    public class entities
    {
        public static void main(string[] args)
        {

            security security = new security()
            {
                id = guid.newguid(),
                denomination = 1,
                name = "a",
                quatation = "z",
                reportperiods = new list<reportperiod>()
            };
            security.reportperiods.add(new reportperiod()
            {
                amount = 10,
                security = security,
                securityid = security.id,
                end = datetime.now.adddays(1),
                start = datetime.now,
                id = guid.newguid(),
                stockexchangeid = guid.newguid()
            });
            security.reportperiods.add(new reportperiod()
            {
                amount = 5,
                security = security,
                securityid = security.id,
                end = datetime.now.adddays(1),
                start = datetime.now,
                id = guid.newguid(),
                stockexchangeid = guid.newguid()
            });
            security.reportperiods.add(new reportperiod()
            {
                amount = 5,
                security = security,
                securityid = security.id,
                end = datetime.now.adddays(1),
                start = datetime.now.addmonths(-1),
                id = guid.newguid(),
                stockexchangeid = guid.newguid()
            });

            foreach (var groupedreportvalues in security.reportperiods
                .groupby(period => new { period.start.year, period.start.month }).select(
                    groupedonmonth => new
                    {
                        startyear = groupedonmonth.key.year,
                        startmonth = groupedonmonth.key.month,
                        amountsum = groupedonmonth.sum(reportvalue => reportvalue.amount)
                    }))
            {
                console.writeline(groupedreportvalues.startyear);
                console.writeline(groupedreportvalues.startmonth);
                console.writeline(groupedreportvalues.amountsum);
                console.writeline();
            }

            console.readline();
        }
    }
}