EF 主键自增、级联删除

 public class Destination
    {
        public int DestinationId { get; set; }
        public string Name { get; set; }
        public string Country { get; set; }
        public string Description { get; set; }
        public byte[] Photo { get; set; }
        public List<Lodging> Lodgings { get; set; }
    }

    public class Lodging
    {
        public int LodgingId { get; set; }
        public string Name { get; set; }
        public string Owner { get; set; }
        public bool IsResort { get; set; }
        public decimal MilesFromNearestAirport { get; set; }
        [Required]
        public Destination Destination { get; set; }
    } 

modelBuilder.Entity<Lodging>().HasRequired(l => l.Destination).WithMany(d => d.Lodgings).WillCascadeOnDelete(true);

modelBuilder.Entity<Lodging>().HasRequired(l => l.Destination).WithMany(d => d.Lodgings).WillCascadeOnDelete(false);