SqlException：当IDENTITY_INSERT设置为OFF ASP.NET Core 2.1

如何解决SqlException：当IDENTITY_INSERT设置为OFF ASP.NET Core 2.1

在数据库中插入新产品时，出现以下SQL错误消息：

表格：

错误SQL：

我一直在寻找有关它的信息，这是一个SQL错误，可以从Entity Framework中修复该错误，但收效不佳

我涉及的模型如下...

Producto.CS：

public class Producto : IEntity
{
    
    public int Id { get; set; }

    [Display(Name = "Nombre")]
    [MaxLength(50,ErrorMessage = "El campo {0} solo puede contener {1} caracteres de largo.")]
    [Required]
    public string Name { get; set; }

    [Display(Name = "Descripción")]
    [MaxLength(150,ErrorMessage = "El campo {0} solo puede contener {1} caracteres de largo.")]
    [Required]
    public string Description { get; set; }

    [Display(Name = "Precio")]
    [DisplayFormat(DataFormatString = "{0:C2}",ApplyFormatInEditMode = false)]
    public decimal Price { get; set; }

    [Display(Name = "Imagen")]
    public string ImageUrl { get; set; }

    public User User { get; set; }

    public Category Category { get; set; }
}

类别。CS：

 public class Category : IEntity
    {
        
        public int Id { get; set; }

        [Display(Name = "Nombre Categoría")]
        [Required (ErrorMessage = "El campo categoría es obligatorio.")]
        [MaxLength(30,ErrorMessage = "el campo {0} solo puede contener {1} caracteres de largo.")]
        public string Name { get; set; }

    }

IEntity.CS：

   public interface IEntity
   {
       int Id { get; set; }
            
   }

为我的产品控制器添加了POST操作。

 [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Create(ProductoViewModel view)
        {
            if (ModelState.IsValid)
            {
                var path = string.Empty;

                if (view.ImageFile != null && view.ImageFile.Length > 0)
                {
                    var guid = Guid.NewGuid().ToString();
                    var file = $"{guid}.jpg";

                    path = Path.Combine(Directory.GetCurrentDirectory(),"wwwroot\\images\\Productos",file);

                    using (var stream = new FileStream(path,FileMode.Create))
                    {
                        await view.ImageFile.CopyToAsync(stream);
                    }

                    path = $"~/images/Productos/{file}";
                }

                //TRANSFORMO EL PRODUCTO PRODUCTOVIEWMODEL A PRODUCTO
                var producto = this.ToProducto(view,path);

                //USUARIO CREADOR
                producto.User = await userHelper.GetUserByEmailAsync(User.Identity.Name);

                //CATEGORIA DEL PRODUCTO
                producto.Category = await categoryRepository.GetByIdAsync(view.CategoryId);

                await productoRepository.CreateAsync(producto);

                //FALTA VALIDAR QUE DEVUELVE (TRUE OR FALSE)            
                return RedirectToAction(nameof(Index));
            }

            return View(view);
        }

        private Producto ToProducto(ProductoViewModel view,string path)
        {
            return new Producto
            {
                Id = view.Id,ImageUrl = path,IsAvailabe = view.IsAvailabe,LastSale = view.LastSale,Name = view.Name,Description = view.Description,Price = view.Price,Stock = view.Stock,User = view.User,Category = view.Category
            };
        }

通过跟踪断点，确保我发送的是有效模型

我正在占用存储库模式，并且在POST操作中，我的系统在以下行崩溃

 await productoRepository.CreateAsync(producto);

我附上我的 IProductoRepository.CS：

  public interface IProductoRepository :  IGenericRepository<Producto>
    {

        IQueryable GetAllWithCategories();

        IQueryable GetAllWithUser();

        IEnumerable<SelectListItem> GetComboProductos();

    }

GenericRepository.CS：

  public class GenericRepository<T> : IGenericRepository<T> where T : class,IEntity
    {
        private readonly DataContext context;

        public GenericRepository(DataContext context)
        {
            this.context = context;
        }

        public async Task<T> CreateAsync(T entity)
        {
            await this.context.Set<T>().AddAsync(entity);
            await SaveAllAsync();
            return entity;
        }
    }

这是怎么回事？为什么我不能保存带有各自类别的产品？

我已经在SQL引擎中验证了各种密钥

我将附加我的 DataContext.CS 作为附加信息：

     public class DataContext : IdentityDbContext<User>
        {
           
            public DbSet<Producto> Productos { get; set; }
            public DbSet<Category> Categories { get; set; }
    
    
            #region Constructor
            public DataContext(DbContextOptions<DataContext> options) : base(options)
            {
    
            }
            #endregion

   //METODO QUE DESHABILITA EL BORRADO EN CASCADA 
        //Y ELIMINA LOS WARNING AL MIGRAR LA BASE DE DATOS
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            //MANTISA DE 18 NUMEROS Y DOS DECIMALES
            modelBuilder.Entity<Producto>().Property(p => p.Price).HasColumnType("decimal(18,2)");

            //DESHABILITAR EL BORRADO EN CASCADA
            var cascadeFKs = modelBuilder.Model
                .G­etEntityTypes()
                .SelectMany(t => t.GetForeignKeys())
                .Where(fk => !fk.IsOwnership && fk.DeleteBehavior == DeleteBehavior.Casca­de);

            foreach (var fk in cascadeFKs)
            {
                fk.DeleteBehavior = DeleteBehavior.Restr­ict;
            }

            base.OnModelCreating(modelBuilder);
        }
    }
    
        }

我尝试将以下DataAnnotations添加到相关的类中：

1. [键]
2. [DatabaseGenerated（DatabaseGeneratedOption.Identity）]
3. [ForeignKey（“ ....”）]

还删除了数据库，我再次尝试了一切

我还验证了我的SQL的身份规范值

我知道这是一个已知的ASP.NET Core错误，但是如何在2.1版中修复它？我忘记了什么吗？对我有帮助吗？

解决方法

public class Category : IEntity
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]   
    public int Id { get; set; }

    [Display(Name = "Nombre Categoría")]
    [Required (ErrorMessage = "El campo categoría es obligatorio.")]
    [MaxLength(30,ErrorMessage = "el campo {0} solo puede contener {1} caracteres de largo.")]
    public string Name { get; set; }

    public IList<Producto> Productos { get; set; }
}

public class Producto : IEntity
{    
  [Key]
  [DatabaseGenerated(DatabaseGeneratedOption.Identity)]   
  public int Id { get; set; }

  [Display(Name = "Nombre")]
  [MaxLength(50,ErrorMessage = "El campo {0} ....")]
  [Required]
  public string Name { get; set; }

  [Display(Name = "Descripción")]
  [MaxLength(150,ErrorMessage = "El campo {0} solo puede contener {1} 
  caracteres de largo.")]
  [Required]
  public string Description { get; set; }

  [Display(Name = "Precio")]
  [DisplayFormat(DataFormatString = "{0:C2}",ApplyFormatInEditMode = false)]
  public decimal Price { get; set; }

  [Display(Name = "Imagen")]
  public string ImageUrl { get; set; }

  public User User { get; set; }

  public int CategoryId { get; set; }

  [ForeignKey(nameof(CategoryId))]
  public Category Category { get; set; }
 }