如何根據兒童孩子的人數排序EF父母？

Question

我隊 S的編碼器小號項目 S的任務 S的。

如何有效地排序隊 01用任務 S IN實體框架的使用方法的語法和代碼優先的方法號（可能沒有加載兒童兒童的整個集合內容，我需要那種只）？

public class MyAppContext : DbContext 
{ 
    public DbSet<CTeam> Teams { get; set; } 
    // ...etc 
} 

 

[Table("Team")] 
public class CTeam 
{ 

    public int ID { get; set; } 

    [MaxLength(128)] 
    public string Title { get; set; } 

    [Display(Name = "Coders")] 
    public virtual ICollection<CCoder> Coders { get; set; } 
} 



[Table("Coder")] 
public class CCoder 
{ 

    public int ID { get; set; } 

    [MaxLength(128)] 
    public string Name { get; set; } 

    public virtual ICollection<CProject> Projects { get; set; } 

    public int TeamID { get; set; } 
    public virtual CTeam Team { get; set; } 
} 

// CProject and CTask similarly 

或者，如果你可以給一個暗示原始的SQL應該怎麼看起來像這個，這將有助於太。謝謝！

UPDATE

與關係Builder -> NewBuildingObject -> NewBuildingHouse -> NewBuildingLayout

對於觀衆的舒適，特奧多爾·伊萬諾夫的回答一個項目：

context.Teams 
.OrderBy(x => x.Coders 
    .SelectMany(y => y.Projects) 
    .SelectMany(y => y.Tasks) 
    .Count()); 

做出EF生成驗證碼：

SELECT 
    [Project1].[ID] AS [ID], 
    [Project1].[Title] AS [Title] 
    FROM (SELECT 
     [Extent1].[ID] AS [ID], 
     [Extent1].[Title] AS [Title], 
     (SELECT 
      COUNT(1) AS [A1] 
      FROM [dbo].[NewBuildingObject] AS [Extent2] 
      INNER JOIN [dbo].[NewBuildingHouse] AS [Extent3] ON [Extent2].[ID] = [Extent3].[ObjectID] 
      INNER JOIN [dbo].[NewBuildingLayout] AS [Extent4] ON [Extent3].[ID] = [Extent4].[HouseID] 
      WHERE [Extent1].[ID] = [Extent2].[BuilderID]) AS [C1] 
     FROM [dbo].[Builder] AS [Extent1] 
    ) AS [Project1] 
    ORDER BY [Project1].[C1] ASC 

和雅各布·馬薩德的回答是：

var teams = context.Teams 
    .OrderBy(team => 
     team.Coders.SelectMany(coder => 
      coder.Projects.SelectMany(project => project.Tasks)).Count()); 

使這個代碼：

SELECT 
    [Project1].[ID] AS [ID], 
    [Project1].[Title] AS [Title] 
    FROM (SELECT 
     [Extent1].[ID] AS [ID], 
     [Extent1].[Title] AS [Title], 
     (SELECT 
      COUNT(1) AS [A1] 
      FROM [dbo].[NewBuildingObject] AS [Extent2] 
      INNER JOIN (SELECT [Extent3].[ObjectID] AS [ObjectID] 
       FROM [dbo].[NewBuildingHouse] AS [Extent3] 
       INNER JOIN [dbo].[NewBuildingLayout] AS [Extent4] ON [Extent3].[ID] = [Extent4].[HouseID]) AS [Join1] ON [Extent2].[ID] = [Join1].[ObjectID] 
      WHERE [Extent1].[ID] = [Extent2].[BuilderID]) AS [C1] 
     FROM [dbo].[Builder] AS [Extent1] 
    ) AS [Project1] 
    ORDER BY [Project1].[C1] ASC 

Answer 1

你可以嘗試像

context.Teams 
.OrderBy(x => x.Coders 
    .SelectMany(y => y.Projects) 
    .SelectMany(y => y.Tasks) 
    .Count()); 

Answer 2

您可以使用SelectMany這樣的：

var teams = context.Teams 
    .OrderBy(team => 
     team.Coders.SelectMany(coder => 
      coder.Projects.SelectMany(project => project.Tasks)).Count());