如何按月獲得運行總數

Question

我正在嘗試填充圖形，我的模型看起來像這樣

public class Transaction : BaseEntity
{
    public TransactionType TransactionType { get; set; }
    public DateTime TransactionDate { get; set; }
    public double TransactionAmount { get; set; }
}
public enum TransactionType{
    Deposit = 0,
    Withdraw = 1
}

我用 2018 年前 2 個月的樣本數據填充了這個模型。

    b.HasData(new
            {
                Id = Guid.NewGuid().ToString(),
                AccountId = "37846734-172e-4149-8cec-6f43d1eb3f60",
                TransactionAmount = 3334.38,
                TransactionDate = new DateTime(DateTime.UtcNow.AddYears(-2).Year, 1, 20),
                TransactionType = TransactionType.Deposit
            });
            b.HasData(new
            {
                Id = Guid.NewGuid().ToString(),
                AccountId = "37846734-172e-4149-8cec-6f43d1eb3f60",
                TransactionAmount = -3334.38,
                TransactionDate = new DateTime(DateTime.UtcNow.AddYears(-2).Year, 1, 21),
                TransactionType = TransactionType.Withdraw

            });
            b.HasData(new
            {
                Id = Guid.NewGuid().ToString(),
                AccountId = "37846734-172e-4149-8cec-6f43d1eb3f60",
                TransactionAmount = 1000.23,
                TransactionDate = new DateTime(DateTime.UtcNow.AddYears(-2).Year, 1, 25),
                TransactionType = TransactionType.Deposit
            });
            b.HasData(new
            {
                Id = Guid.NewGuid().ToString(),
                AccountId = "37846734-172e-4149-8cec-6f43d1eb3f60",
                TransactionAmount = 1008.18,
                TransactionDate = new DateTime(DateTime.UtcNow.AddYears(-2).Year, 4, 10),
                TransactionType = TransactionType.Deposit
            });
            b.HasData(new
            {
                Id = Guid.NewGuid().ToString(),
                AccountId = "37846734-172e-4149-8cec-6f43d1eb3f60",
                TransactionAmount = -34.10,
                TransactionDate = new DateTime(DateTime.UtcNow.AddYears(-2).Year, 4, 19),
                TransactionType = TransactionType.Withdraw
            });

我試圖得到一個結果，即每個月末的余額是多少。

例如在

2018 年 1 月 1000.23
4 月 1974.23（1 月為 1000.23 + 4 月為 974.0）

但我得到的是

1 月 1000.23
四月 974.0

基本上它是單獨添加每個月的所有值。

 var data = from t in transactions
                   group t by new { t.TransactionDate.Year, t.TransactionDate.Month } into g
                   select new
                   {
                       //Balance = g.Select(i =>
                       //{
                       //    currentTotal += g.Sum(x => x.TransactionAmount);
                       //    return new
                       //    {
                       //        //Date = i.TransactionDate,
                       //        //Amount = i.TransactionAmount,
                       //        currentTotal
                       //    };
                       //}),
                       Balance = g.Sum(x => x.TransactionAmount),
                       g.First().TransactionDate.Month,
                       g.First().TransactionDate.Year
                   };
        var yearlyGroups = data.OrderBy(x => x.Month).GroupBy(x => x.Year);
        var lastTwoYearsSortedByMonth = yearlyGroups.OrderBy(x => x.Key).TakeLast(2);

正如您在上面的代碼中看到的，我嘗試了一些方法來獲得運行總數。 但不工作。

Answer 1

我想我的建議誤導了你。 我.Aggregate()一個足夠優雅的解決方案來使用.Aggregate() 。

    var runningBalance = 0.0;
    var data = transactions.GroupBy(t => new { t.TransactionDate.Year, t.TransactionDate.Month })
        .OrderBy(d => d.Key.Year)
        .ThenBy(dd => dd.Key.Month)
        .Select((g) => new
        {
            Year = g.Key.Year,
            Month = g.Key.Month,
            Balance = g.Sum(i => i.TransactionAmount),
            RunningBalance = (runningBalance = (runningBalance + g.Sum(i => i.TransactionAmount)))
        });