分级分层Linq中

Question

如果我有一组类似的员工数据：

var users = new[] 
{ 
    new {SupervisorId = "CEO", UserId = "CEO", UserName = "Joe"}, 
    new {SupervisorId = "CEO", UserId = "CIO", UserName = "Mary"}, 
    new {SupervisorId = "CIO", UserId = "XDIR", UserName = "Ed"}, 
    new {SupervisorId = "CIO", UserId = "YDIR", UserName = "Lisa"}, 
    new {SupervisorId = "XDIR", UserId = "AMNGR", UserName = "Steve"}, 
    new {SupervisorId = "AMNGR", UserId = "ASUP", UserName = "Lesley"} 
}; 

是否可以使用Linq添加分级层，在这个意义上说：

• CEO = 1（顶部）
• CIO = 2（第二级）
• XDIR和YDIR = 3（第三级）
• AMNGR = 4（等）
• ASUP = 5（等）

我已经能集团员工根据SupervisorId，但不知道如何使“水平”发生。

var userGroups = from user in users 
    group user by user.SupervisorId into userGroup 
    select new 
    { 
    SupervisorId = userGroup.Key, 
    Level = ?????? 
    Users = userGroup.ToList() 
    }; 

    foreach (var group in userGroups) 
    { 
    Console.WriteLine("{0} - {1} - {2}", group.SupervisorId, group.Level, group.Users.Count); 
    } 

非常感谢。

Answer 1

我想补充的排名到您的LINQ“用户对象”

public class User{ 

    public string SupervisorId {get;set;} 
    public string UserId {get;set;} 
    public string UserName {get;set;} 
    public int Level {get { return GetRank(SupervisorId ) ; } } 

    private int GetRank(string userId){ 
    if(string.IsNullOrEmpty(userId)){ 
     //Bad case, probably want to use a very large number 
     return -1; 
    } 
    int level = 0; 
    switch(userId){ 
     case "CEO": 
      level = 0; 
      break; 

     //insert others here 

    } 

    } 
} 

那么你的Linq您将添加一个连接。

 var userGroups = from user in users 
        join super in users on user.SupervisorId equals super.UserId 
        group user by user.SupervisorId into userGroup 
        select new 
    { 
     SupervisorId = userGroup.Key, 
     Level = super.Level, 
     Users = userGroup.ToList() 
    }; 

Answer 2

更新

继承人之一，创建一个查找表为每个级别的方式。它相当，我不知道它会如何扩大。显然，您需要调整它以从数据库中提取行。

定义一个类来保存我们的查找表

public class user{ 
    public string SupervisorId; 
    public string UserId; 
    public int Level; 
} 

然后我们得到用户名/ SupervisorId组合和循环的唯一列表通过列表计算每个组合的水平通过“走”了树。

var uniqueusers = (new user[] 
     { 
      new user {SupervisorId = "CEO", UserId = "CEO"}, 
      new user {SupervisorId = "CEO", UserId = "CIO"}, 
      new user {SupervisorId = "CIO", UserId = "XDIR"}, 
      new user {SupervisorId = "CIO", UserId = "YDIR"}, 
      new user {SupervisorId = "XDIR", UserId = "AMNGR"}, 
      new user {SupervisorId = "AMNGR", UserId = "ASUP"} 
     }).Distinct(); 


     foreach (var item in uniqueusers) 
     {   
      int level = 0; 
      user CurrentUser = item; 
      while (CurrentUser.UserId != CurrentUser.SupervisorId){ 
       CurrentUser = uniqueusers.Where(c => c.UserId == CurrentUser.SupervisorId).FirstOrDefault(); 
       level++; 
      } 
      item.Level = level;    
     } 

现在，您可以使用uniqueusers作为查找表来确定查询的级别。例如：

private int GetLevel(string userId){   
    return uniqueusers.Where(c => c.UserId == userId).FirstOrDefault().Level;  
    } 

你甚至可以用一点努力将它结合成一个单一的步骤。

Answer 3

ILookup<string, User> subordLookup = users 
    .ToLookup(u => u.SupervisorId); 

foreach(User user in users) 
{ 
    user.Subordinates = subordLookup[user.UserId].ToList(); 
} 

User userHierarchy = user.Single(u => u.UserId == "CEO"); 

免责声明：

• 不处理多个老总。
• 保留循环关系。
• 遗落的孤儿。

Answer 4

这是你在找什么？

  var levels = new[] 
     { 
      new { Level = 1, LevelName = "CEO" }, 
      new { Level = 2, LevelName = "CIO" }, 
      new { Level = 3, LevelName = "XDIR" }, 
      new { Level = 3, LevelName = "YDIR" }, 
      new { Level = 4, LevelName = "AMNGR" }, 
      new { Level = 5, LevelName = "ASUP" } 
     };       

     var userGroups = from user in users 
         join level in levels on 
         user.UserId equals level.LevelName        
         group new{ User = user, Level = level.Level } by new { SuperId = user.SupervisorId, Level = level.Level } into userGroup 
         select new 
          { 
           SupervisorId = userGroup.Key.SuperId, 
           Level = userGroup.Key.Level, 
           Users = userGroup.ToList() 
          };