LINQ的GroupBy多個列和Count

Question

模型類

public class tstsStates 
{ 
    public string Name { get; set; } 
    public string title{ get; set; } 
    public int jcount { get; set; } 
    public int DCount { get; set; } 
    public Guid JobId { get; set; } 
    public Guid PId { get; set; } 
    public Guid JId { get; set; } 
    public DateTime Date { get; set; } 
} 

我LAMBDA查詢

List<model> list= _context.Table 
    .Include(x => x.Table1) 
    .Include(x => x.Table2) 
    .Include(x => x.Table2) 
    .Where(x => Ids.Contains(x.Table4.Id)) 
    .Select(x => new model 
    { 
     Name = x.table.FirstName + "" + x.table.LastName, 
     Position = x.table.Title, 
     JobId = x.table.Id, 
     id= x.Id, 
     rId= x.Id, 
     Date = x.Date 

    }).ToList(); //Till here query works absolutely fine. 


// How i can group two columns and get the count. 

我的問題：

1）我被兩列丟失分組的邏輯（ PId，jbId），計數並將其分配回我的模型以返回查看。

2）我錯過了由兩列（pid，mydate）分組的邏輯，將dCount分配給我的模型並將其返回給視圖。

我的要求

jcount：我需要採取鮮明JobIds的數量從上面的IEnumerable？

dcount：我需要從IEnumerable上面計算不同日期的計數嗎？

原因：

Answer 1

至於我也明白了，你要顯示的JobsCount &天計算每個人，每個都具有不同的一組標題的，在這種情況下，試試這個： -

var result = tstPData.GroupBy(x => new { x.PersonnelId, x.Name , x.Position }) 
        .Select(x => new 
            { 
             PersonnelId = x.Key.PersonnelId, 
             Name = x.Key.Name, 
             Position = x.Key.Position , 
             JobCount = x.Count(), 
             DaysCount = x.Count() 
            }); 

最後，您可以枚舉結果並分配給您的模型。

更新：根據您的型號

我已創建自定義的數據對象： -

List<PersonnelStats> persons = new List<PersonnelStats> 
      { 
       //Same Job for Alex but different date 
       new PersonnelStats { Name="Alex", Position="Dev", JobId= new Guid("11223344-5566-7788-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-5566-7788-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,12)}, 
       new PersonnelStats { Name="Alex", Position="Dev", JobId= new Guid("11223344-5566-7788-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-5566-7788-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,15)}, 
       //Two jobs for Mary 
       new PersonnelStats { Name="Mary", Position="App", JobId= new Guid("11229944-2356-7788-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-1567-6565-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,13)}, 
       new PersonnelStats { Name="Mary", Position="App", JobId= new Guid("11229944-3445-7788-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-1567-6565-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,13)}, 
       //Two jobs for Mark with 1 job being at different dates. 
       new PersonnelStats { Name="Mark", Position="Test", JobId= new Guid("11223344-7879-2344-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-2245-4343-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,17)}, 
       new PersonnelStats { Name="Mark", Position="Test", JobId= new Guid("11223344-5522-2344-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-2245-4343-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,17)}, 
       new PersonnelStats { Name="Mark", Position="Test", JobId= new Guid("11223344-5522-2344-99AA-BBCCDDEEFF00"), PersonnelId = new Guid("11223344-2245-4343-99AA-BBCCDDEEFF00"), Date= new DateTime(2015,03,18)}, 
      }; 

這是給我所需要的輸出代碼： -

  var result = persons.GroupBy(x => new { x.PersonnelId, x.Name, x.Position }) 
        .Select(x => new 
        { 
         PersonnelId = x.Key.PersonnelId, 
         Name = x.Key.Name, 
         Position = x.Key.Position, 
         JobCount = x.Select(z => z.JobId).Distinct().Count(), 
         DaysCount = x.Select(z => z.Date.Date).Distinct().Count() 
        });