linq聚集

假设我有如下课程：

    public class ServiceCall 
    { 
        public int ServiceCallID {get; set;}
        public DateTime ReportedTimestamp {get; set;}
        public bool IsPaid {get; set;}
        public decimal LabourNet { get; set;}
        public decimal LabourVat {get; set;}
    }
    public class UsedPart
    {
        public int UsedPartID { get; set; }
        public decimal NetPrice { get; set; }
        public decimal VatAmount {get; set;}
    }

我想以以下格式返回数据：

Month    #CallsReceived   AmountInvoiced    MoneyReceived
Jan 2009 202              €32050.20         €29200.00
Feb 2009 213              €35050.20         €34200.00

发票金额是一个月内所有（净价格+增值税金额）+（LabourNet+LabourVat）净额的总和，收到的金额是所有金额的总和，其中IsPaid=true。 我在获取此报表的正确linq查询时遇到问题。我不确定在哪里分组以及何时执行求和

我目前的linq查询如下所示，但我目前没有得到任何接近我想要的东西。有人有点善良吗

var q = from s in ServiceCalls
 join up in UsedParts on s.ServiceCallID equals up.ServiceCallID into tmp
 from nullablePart in tmp.DefaultIfEmpty()
 group s by s.ReportedTimestamp.Month
 into grp
 select new 
  { 
   Month = grp.Key,
   CallsReceived = grp.Count(),
   AmountInvoiced = grp.Sum(s => s.UsedParts.Sum(p => p.NetPrice)),
  };

---

好的，我必须把它分解成几个子查询才能让它工作。很可能有更好、更有效的方法来实现这一点，但目前我有一个linq解决方案。不包括获取收到的钱的代码，因为它与其他代码非常相似，只是在IsPaid=true上过滤

在我使用LLBL Gen Pro时，我的环境略有不同，但您可以从以下代码中获得基本要点：

// Get the number of calls by month
var callsCount = from s in ServiceCalls group s by new DateTime(s.ReportedTimestamp.Year, s.ReportedTimestamp.Month, 1) into grp select new { ReportDate = grp.Key, Count = grp.Count()};
//callsCount.Dump();

// Get the labour on all calls by month
var serviceCallLabour = from s in ServiceCalls 
    select new 
    { 
        ReportDate = new DateTime(s.ReportedTimestamp.Year, s.ReportedTimestamp.Month, 1), 
        IsPaid = s.IsPaid, 
        GrossLabour = s.LabourChargeNet + s.LabourChargeVat 
    } 
    into labour
    group labour by labour.ReportDate into grp
    select new  {ReportDate = grp.Key, IsPaid = grp.Select(l => l.IsPaid).First(), GrossLabour = grp.Sum(l => l.GrossLabour) };
//serviceCallLabour.Dump();

// Get the value of parts used on all calls by month
var serviceCallParts = from s in ServiceCalls 
    join up in UsedParts on s.ServiceCallID equals up.ServiceCallID into tmp
    from np in tmp.DefaultIfEmpty()
    select new 
    { 
        ReportDate = new DateTime(s.ReportedTimestamp.Year, s.ReportedTimestamp.Month, 1),
        GrossPart = np != null ? (np.NetPrice + np.VatAmount) : 0
    }
    into callParts
    group callParts by callParts.ReportDate into grp
    select new { ReportDate = grp.Key, GrossPart = grp.Sum(p => p.GrossPart) };
//serviceCallParts.Dump();

var results = from l in serviceCallLabour
                join p in serviceCallParts on l.ReportDate equals p.ReportDate
                join c in callsCount on l.ReportDate equals c.ReportDate                
                select new { ReportDate = l.ReportDate, CallsReceived = c.Count, AmountInvoiced = l.GrossLabour + p.GrossPart} into callAmounts
                group callAmounts by callAmounts.ReportDate into grp
                select new {Month = grp.Key, CallsReceived = grp.Select(c => c.CallsReceived).First(), AmountInvoiced = grp.Sum(c => c.AmountInvoiced)};

results.Dump();

---

我知道这是一个古老的历史问题，但这里是我的答案

var byMonth =
    from sc in ServiceCalls
    join up in UsedParts
        on sc.ServiceCallID equals up.ServiceCallID
        into gups
    let tsd = sc.ReportedTimestamp.Date
    let month = tsd.AddDays(1 - tsd.Day)
    group new
    {
        Calls = 1,
        sc.IsPaid,
        ChargeNet = sc.LabourNet + gups.Sum(gup => gup.NetPrice),
        ChargeVat = sc.LabourVat + gups.Sum(gup => gup.VatAmount),
    } by month into gscs
    select new
    {
        Month = gscs.Key,
        CallsReceived = gscs.Sum(gsc => gsc.Calls),
        AmountInvoiced
            = gscs.Sum(gsc => gsc.ChargeNet)
            + gscs.Sum(gsc => gsc.ChargeVat),
        MoneyReceived
            = gscs.Sum(gsc => gsc.IsPaid ? gsc.ChargeNet : 0m)
            + gscs.Sum(gsc => gsc.IsPaid ? gsc.ChargeVat : 0m),
    };

---

享受吧

请告诉我们你得到了什么。请记住，这将在“一年中的一个月”而不是“一年中的一个月”进行汇总-即，它将在2009年2月和2008年2月进行汇总。显示我目前拥有的东西没有多大意义，因为它确实有点到处都是。基本上，我想做的是从细节行聚合数据，并在主行上按年/月对数据进行分组。在sql中不是很难，但在linq中似乎不太可能正确。我认为，它将不得不细分为几个问题。有什么好办法吗？