Find deleted item but throw exception-CodePudding

I have two entity class as below :

class SessionMaster 
{
  public int ID { get; set; }      
  public string SessionTag { get; set; }
  public List<SessionLog> SessionLogs { get; set; }
}
class SessionLog
{
  public long ID { get; set; }
  public int SessionMasterID { get; set; }      
  public string LogMessage { get; set; }      
}

For and I have FormObject define as below :

class FO_SessionMaster 
{
      public int? ID { get; set; }      
      public string SessionTag { get; set; }
      public List<FO_SessionLog> fo_SessionLogs { get; set; }
}
class FO_SessionLog 
{
      public long? ID { get; set; }
      public int? SessionMasterID { get; set; }
      public string LogMessage  { get; set; }    
}

for some reason, Front end will pass null value during update During work on delete Item of SessionLogs, I want to find out which log detail is deleted, I try to work on below :

public void UpdateSession (FO_SessionMaster formData) 
{
  var findDeletedLog = dBContext.Set<SessionLog>().Where(w => w.SessionMasterID == formData.ID && !formData.fo_SessionLogs.Any(a => (long)a.ID == w.ID));
  var getFirstRecord = findDeletedLog.First();
}

when I go to findDeletedLog.First(), it throw exception : System.InvalidOperationException: .... 'The LINQ expression could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'. Even I turn into list is not work, Can I know how to solve it ?

CodePudding user response：

I think the problem is that LINQ does not support using Any on this local in-memory collection. Note that the LINQ provider needs to translate your code to valid sql.

Try this:

public void UpdateSession (FO_SessionMaster formData) 
{
    List<long> sessionLogIdList = formData.fo_SessionLogs
        .Select(sl => (long) a.ID)
        .ToList();

    var findDeletedLog = dBContext.Set<SessionLog>()
        .Where(w => w.SessionMasterID == formData.ID && !sessionLogIdList.Contains(w.ID));

    // ...
}