问使用映射另一个类的Litedb，插入第一个对象，但在主值内映射的对象为空或默认

EN

public class Player
    {
        public Guid Id { get; set; }
        public string PlayerName { get; set; }
        public long SoundCardId { get; set; }
        public string SoundCardName { get; set; }
        public Guid PlayerId { get; set; }
        public long? Volume { get; set; }
        public long OutputChannel { get; set; }
        public Guid HardwareId { get; set; }
        public IList<Schedules> Schedules { get; set; }
    }

  
    public class Schedule
    {
        public Guid Id { get; set; }
        public DateTime startDate { get; set; }
        public DateTime endDate { get; set; }
        public DateTime startTime { get; set; }
        public DateTime endTime { get; set; }
        public int PlayDays { get; set; }
        public string ScheduleName { get; set; }
        public int Volume { get; set; }
        public bool hasPriority { get; set; }
        public bool isActive { get; set; }
        public bool shuffleEnabled { get; set; }
        public bool HarmonicShuffleEnabled { get; set; }
        public DateTime LastUpdateDate { get; set; }
       
      
    }

               string dbPath = Path.Combine(Application.StartupPath, "music.db");
            // set id as bsonid
            BsonMapper.Global.Entity<Schedule>().Id(oid => oid.Id);

            //set id as bsonid and ref other table
            BsonMapper.Global.Entity<Player>()
                .Id(oid => oid.Id)
                .DbRef(x => x.Schedules, "SchedulesTable");




            using (var db = new LiteDatabase(dbPath))
            {
                //create if not exists 
                var p1 = db.GetCollection<Player>("PlayerTable");
                var p2 = db.GetCollection<Schedule>("SchedulesTable");

                var p = new Player
                {
                    PlayerId = Guid.NewGuid(),
                    HardwareId = Guid.NewGuid(),
                    OutputChannel = 1,
                    PlayerName = "default player",
                    SoundCardId = -1,
                    SoundCardName = "Default sound card",
                    Volume = 100,
                    Id = Guid.NewGuid(),
                    Schedules = new List<Schedule>()
                };

                var col = db.GetCollection<Player>("PlayerTable");

                var q = col.Query().Include(c => c.Schedules).ToList();
                if (q.Count() == 0)
                {
                    var sch = new Schedule
                    {
                        Id = Guid.NewGuid(),
                        startDate = DateTime.Now,
                        endDate = DateTime.Now.AddDays(2),
                        startTime = DateTime.Now.Add(new TimeSpan(0, 0, 1)),
                        endTime = DateTime.Now.Add(new TimeSpan(22, 0, 0)),
                        isActive = true,
                        HarmonicShuffleEnabled = true,
                        hasPriority = false,
                        LastUpdateDate = DateTime.Now,
                        PlayDays = 127,
                        ScheduleName = "test schedule",
                        shuffleEnabled = true,
                        Volume = 100
                    };

                    p.Schedules.Add(sch);
                    var r1 = col.Insert(p);

                    col.EnsureIndex(c => new { c.HardwareId, c.PlayerId }, true);
                    //lets check if insert success?
                    var q1 = col.Query().Include(c => c.Schedules).FirstOrDefault();
                    //yes its inserted without any problem
                    var q2 = q1.Schedules.FirstOrDefault();
                    //yes there is one record.. 
                    //and the Id is the same with sch.Id 
                    // but the rest of the properties are null or empty

                }