有沒有辦法使用lambda表達式編寫此LINQ查詢？

Question

我有一個linq查詢，使用2個聯接從3個表中獲取數據。 我更喜歡將其編寫為lambda表達式，以便我的團隊發現它更具可讀性。 有辦法嗎？ 我找不到任何合適的例子。

var q = (
     from sus in susManager.Get()
     join su in suManager.Get() on sus.SUId equals su.Id
     join p in pManager.Get() on su.PId equals p.Id
     where sus.EndTimeStamp >= oneDayAgo
     select new
     {
         Name = p.FirstName + " " + p.LastName,
         Email = su.Email,
         LastLogIn = sus.StartTimeStamp,
         LastSessionDurationInMinutes = 
             DbFunctions.DiffMinutes(sus.StartTimeStamp, sus.EndTimeStamp),
         LastActive = sus.EndTimeStamp
     }).ToList();

Answer 1

假定Get()函數返回List ，則等效的lambda如下所示：

var q = systemUserSessionManager.Get()
    .Where(sus => sus.EndTimeStamp >= oneDayAgo)
    .Join(systemUserManager.Get(), 
        sus => sus.SystemUserId, 
        su => su.Id, 
        (sus, su) => new { sus, su })
    .Join(personManager.Get(), 
        j => j.su.PersonId, 
        p => p.Id, 
        (j, p) => new { sus = j.sus, su = j.su, p })
    .Select(x => new
    {
        Name = p.FirstName + " " + p.LastName,
        Email = su.Email,
        LastLogIn = sus.StartTimeStamp,
        LastSessionDurationInMinutes = 
            DbFunctions.DiffMinutes(sus.StartTimeStamp, sus.EndTimeStamp),
        LastActive = sus.EndTimeStamp
    })
    .ToList();

Answer 2

試試這個

var q = (
     from sus in systemUserSessionManager.Get()
     join su in systemUserManager.Get() on sus.SystemUserId equals su.Id
     join p in personManager.Get() on su.PersonId equals p.Id
     select new { sus = sus, su = su, p = p})
     .Where(x => x.sus.EndTimeStamp >= oneDayAgo)
     .Select(x => new {
         Name = x.p.FirstName + " " + x.p.LastName,
         Email = x.su.Email,
         LastLogIn = x.sus.StartTimeStamp,
         LastSessionDurationInMinutes = 
             DbFunctions.DiffMinutes(x.sus.StartTimeStamp, x.sus.EndTimeStamp),
         LastActive = x.sus.EndTimeStamp
     }).ToList();