EF 6保存相关实体组合键

我有以下EF实体：

public class EmployeeHoliday
    {

        public int HolidayId { get; set; }
        public int EmployeeId { get; set; }
        public DateTime StartDate { get; set; }
        public DateTime EndDate { get; set; }

        public bool IsActive { get; set; }

    }

    public class EmployeeHolidayItem
        {
            public int HolidayId { get; set; }
            public DateTime Date { get; set; }
            public int EmployeeId { get; set; }
            public string MasterEntity { get; set; }
            public bool IsRealHoliday { get; set; }
            public bool IsActive { get; set; }

        }

EF配置图为：

public EmployeeHolidayMap()
        {
            // Primary Key
            this.HasKey(t => t.HolidayId);

            // Properties
            this.Property(t => t.HolidayId)
               .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

            // Properties
            this.Property(t => t.EmployeeId)
                .IsRequired();

            // Table & Column Mappings
            this.ToTable("employee_holiday");
            this.Property(t => t.HolidayId).HasColumnName("holidayid");
            this.Property(t => t.EmployeeId).HasColumnName("employeeid");
            this.Property(t => t.StartDate).HasColumnName("startdate");
            this.Property(t => t.EndDate).HasColumnName("enddate");
            this.Property(t => t.IsActive).HasColumnName("isactive");

        }




public EmployeeHolidayItemMap()
        {
            // Primary Key
            this.HasKey(t => new { t.HolidayId, t.Date });

            this.Property(t => t.EmployeeId)
              .IsRequired();

            this.Property(t => t.MasterEntity)
             .IsRequired();


            // Table & Column Mappings
            this.ToTable("employee_holiday_item");
            this.Property(t => t.HolidayId).HasColumnName("holidayid");
            this.Property(t => t.Date).HasColumnName("date");
            this.Property(t => t.EmployeeId).HasColumnName("employeeid");
            this.Property(t => t.MasterEntity).HasColumnName("masterentity");
            this.Property(t => t.IsRealHoliday).HasColumnName("isrealholiday");
            this.Property(t => t.IsActive).HasColumnName("isactive");
        }

现在，我试图EmployeeHoliday用几个保存一个新文件，EmployeeHolidayItems但是我HolidayId在EmployeeHolidayItems模型中的键上得到了一个错误。

这是用于插入新代码的代码EmployeeHoliday：

int holidayId = 0;

var newRequest = new Model.EmployeeHoliday();

                newRequest.HolidayId = holidayId;

                newRequest.EmployeeId = request.EmployeeId;
                newRequest.StartDate = dates.FirstOrDefault();
                newRequest.EndDate = dates.LastOrDefault();
                newRequest.IsActive = true;


var newRequestDates = new List<Model.EmployeeHolidayItem>();

// Add Days to Holiday Item
                foreach (var date in dates)
                {
                    var newDate = new Model.EmployeeHolidayItem();

                    newDate.HolidayId = holidayId;
                    newDate.EmployeeId = request.EmployeeId;
                    newDate.MasterEntity = Uow.MasterEntity;
                    newDate.Date = date;
                    newDate.IsRealHoliday = true; 
                    newDate.IsActive = true;

                    // add to list
                    newRequestDates.Add(newDate);
                }

DbContext.EmployeeHoliday.Add(newRequest);
DbContext.EmployeeHolidayItem.AddRange(newRequestDates);

DbContext.SaveChanges();

在插入新记录时，有什么方法可以强制EmployeeHoliday和EmployeeHolidayItem之间的关系？我不想在“映射”中建立关系。