BuecherwurmAPI/Models/Item.cs

using System.ComponentModel.DataAnnotations;

namespace BuecherwurmAPI.Models
{
    public class Item
    {
        [Key, Required]
        public long ItemId { get; set; }
        [Required]
        public long BookId { get; set; }
    }
    public class ItemPost
    {
        public int BookId { get; set; }
    }
    
}