如何我可以通过我的全部邮件组

Question

我试图让每个用户的所有邮件的数量

msg 1 = SenderId =1 , ReciverId =2 
msg 2 = SenderId =2 , ReciverId =1 
msg 3 = SenderId =1 , ReciverId =2 

我在我的例子 考虑1个使用相同的用户作为一个消息聊天等等查询需要reurn，我有一个消息

这是什么查询？ 我写了一个查询底部，告诉我想要什么 但是回肠，我怎么写一个工作？

public class UserMessages 
{ 
    public long Id { get; set; } 
    public long SenderId { get; set; } 
    public long ReciverId { get; set; } 
    public string Text { get; set; } 
    public DateTime? DateTime { get; set; } 
    public bool FastMessage { get; set; } 
    public bool SenderDelete { get; set; } 
    public bool ReciverDelete { get; set; } 
    public bool ReciverRead { get; set; } 
} 

     var UserMessages = db.UserMessages 
          .Where(x => (x.SenderId == id && x.SenderDelete == false) || 
             (x.ReciverId == x.Id && x.ReciverDelete == false)) 
          .GroupBy(x => new { x.ReciverId, x.SenderId }) 
          .GroupBy((y, w) => y.Key.SenderId == w.Key.ReciverId 
               && y.Key.ReciverId == w.Key.SenderId) 
          .Count(); 

Answer 1

我采取的是这样的：

var result = db.UserMessages 
       .Where(x => x.SenderId == id || x.ReceiverId == id) 
       .Select(x => x.ReceiverId == id ? x.SenderId : x.ReceiverId) 
       .Distinct() 
       .Count(); 

Answer 2

var id = 1; // the ID of the person to count chat partners for 

var chatPartnerCount = db.UserMessages 
    .Where(x => x.SenderId == id && !x.SenderDelete || x.ReceiverId == id && !x.ReceiverDelete) 
    .GroupBy(x => x.SenderId == id ? x.ReceiverId : x.SenderId) // group by the chat partner 
    .Count(); // count the number of unique chat partners