linq groupby（）和Sum（）

Question

这可能很琐碎，但我不能得到它的工作（LINQ级新手）。

我想为同一天的客户端（日期显示在epoc/unixtime中）对行进行分组和总计。

目前它只显示最大值为21（从Kbytes转换为Gbytes），而不是±26，这是我想看到的。

如何添加GroupBy和Sum子句来为每天添加Kbytes？

public class Images 
{ 
    public string ClientName { get; set; } 
    public string ImageID { get; set; } 
    public int PolicyType { get; set; } 
    public int ScheduleType { get; set; } 
    public Int64 BackupTime { get; set; } 
    public Int64 KBytes { get; set; } 
} 

和

public static List<Images> images = new List<Images>(); 

和

public void calc() 
    { 

     foreach (var client in clients) 
     { 
      totalmax = 0; 
      totalavg = 0; 
      foreach (var ptype in ptypes) 
      { 

       var windowsquery = images 
        .Where(s => s.PolicyType == Convert.ToInt16(ptype) && s.ScheduleType == 0 && s.ClientName == client) 
        .Select(s => s.KBytes); 

       double typemax = windowsquery.DefaultIfEmpty().Max()/1048576; 
       totalmax = Math.Round(totalmax + typemax); 
       double typeavg = windowsquery.DefaultIfEmpty().Average()/1048576; 
       totalavg = Math.Round(totalavg + typeavg); 

      } 
      Console.WriteLine("Client = {0}, Max = {1}, Ave = {2}", client,totalmax, totalavg); 
      Console.ReadKey(); 
     } 
    } 

输出继电器（省略了来自输出的其他客户端）

客户=客户机2，最大值= 21，平均= 14

更新：实施t他的

var summary = (from image in images 
          where image.ScheduleType == 0 
          group image by new 
          { 
           image.ClientName, 
           image.PolicyType, 
           image.ScheduleType, 
           BackupDateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0) 
                     .AddSeconds(image.BackupTime) 
                     .ToString("yyyy-MM-dd") 
          } into imageGroup 
          select new 
          { 
           ClientName = imageGroup.Key.ClientName, 
           PolicyType = imageGroup.Key.PolicyType, 
           BakupDateTime = imageGroup.Key.BackupDateTime, 
           SumGBytes = imageGroup.Sum(s => s.KBytes)/1048576.0, 
           AvgGBytes = imageGroup.Average(s => s.KBytes)/1048576.0, 

          } 
            ).ToList(); 

但总和是不正确的，平均工作正常。

Answer 1

检查这一项。

var summary = (from image in images 
       group image by new { image.ClientName, 
            image.PolicyType, 
            BackupDateTime = new DateTime(1970, 1, 1, 0, 0, 0, 0) 
               .AddSeconds(image.BackupTime) 
               .ToString("MM/dd/yyyy", CultureInfo.InvariantCulture) 
            } into imageGroup 
       select new { ClientName = imageGroup.Key.ClientName, 
          PolicyType = imageGroup.Key.PolicyType, 
          BakupDateTime = imageGroup.Key.BackupDateTime, 
          SumGBytes = imageGroup.Sum(s => s.KBytes)/1048576.0, 
          AvgGBytes = imageGroup.Average(s => s.KBytes)/1048576.0, 
          MaxGBytes = imageGroup.Max(s => s.KBytes)/1048576.0, 
          Records = imageGroup.Count() 
          } 
      ).ToList(); 

可以使用以下查询列出具有转换的BackupTime的所有记录：

var listWithDateTime = (from image in images 
         orderby image.ClientName ascending, 
           image.PolicyType ascending, 
           image.BackupTime ascending 
         select new { 
           ClientName = image.ClientName, 
           PolicyType = image.PolicyType, 
           GBytes = image.KBytes/1048576.0, 
           UnixTimestamp = image.BackupTime, 
           NormalDate = new DateTime(1970, 1, 1, 0, 0, 0, 0) 
              .AddSeconds(image.BackupTime) 
              .ToString("MM/dd/yyyy", CultureInfo.InvariantCulture) 
           } 
         ).ToList(); 

Answer 2

你已经尝试过这个吗？

var windowsquery = images 
        .Where(s => s.PolicyType == Convert.ToInt16(ptype) 
        && s.ScheduleType == 0 && s.ClientName == client) 
        .GroupBy(s => s.date) 
        .Select(s => s.Sum(y=>y.KBytes)); 

在附图中，日期似乎不正确，或者是特殊格式？

Answer 3

这似乎重复后，答案已经在堆栈溢出可用...

var windowsquery = images 
       .Where(s => s.PolicyType == Convert.ToInt16(ptype) && s.ScheduleType == 0 && s.ClientName == client).GroupBy(s => YourDateField) 
       .Select(s => s.Sum(i => i.KBytes)); 

或

var windowsquery = images 
         .Where(s => s.PolicyType == Convert.ToInt16(ptype) && s.ScheduleType == 0 && s.ClientName == client).GroupBy(s => YourDateField) 
         .Select(g=>new { sum = g.Sum(k=>k.KBytes), field = g.Key });