無法確定“ICollection<Product>”型別的導航“Customer.BoughtProducts”表示的關系

我有 3 個模型和一個 User 類，它定義了客戶和賣家的公共屬性，所以我不會附加它（我想這將是無用的資訊）。

public class Seller : User
{
    public bool IsApproved { get; set; }

    public ICollection<Product> WaitingForShipping { get; set; }

    public ICollection<Product> ProductsOnSell { get; set; }
} 

public class Customer : User
{
    public bool IsSubscriber { get; set; }

    public ICollection<Product> WaitingForReceiving { get; set; }

    public ICollection<Product> BoughtProducts { get; set; }
}

public class Product
{
    [Key] public Guid Id { get; set; }

    public string Name { get; set; }

    public decimal Price { get; set; }

    public string Description { get; set; }

    public ProductCategory Category { get; set; }

    public int SellerId { get; set; }
    [ForeignKey("SellerId")] public Seller ProductSeller { get; set; }

    public int CustomerId { get; set; }

    [ForeignKey("CustomerId")] public Customer ProductCustomer { get; set; }

    public ICollection<Characteristic> ProductInfo { get; set; }

    public ICollection<Image> ImagesURLs { get; set; }

    public long Quantity { get; set; }

    public long AmountSold { get; set; }

    public byte Rating { get; set; }

    public bool InStock { get; set; }
}

最后是 DbContext 類

public class AppDbContext : DbContext
{
    public DbSet<Customer> Customers { get; set; }

    public DbSet<Seller> Sellers { get; set; }

    public DbSet<Product> Products { get; set; }

    public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        
        // There were a lot of useless tries of configuring the relationships like
        // this
        // modelBuilder.Entity<Customer>().HasMany(prods => prods.BoughtProducts)
        // .WithOne(s => s.ProductSeller).HasForeignKey(i => i.SellerId);
        base.OnModelCreating(modelBuilder);
    }
}

當我使用：

dotnet ef migrations add inital

進入終端我得到這個：

無法確定“ICollection”型別的導航“Customer.BoughtProducts”表示的關系。手動配置關系，或使用“[NotMapped]”屬性或使用“OnModelCreating”中的“EntityTypeBuilder.Ignore”忽略此屬性。

我不知道如何解決它。

uj5u.com熱心網友回復：

我不知道您的客戶代碼。但我想你可能會使用 ICollection<Product> 不止一個。以賣家為例。

根據您的 Seller.cs，我在產品中添加以下代碼，

        public Guid SellerId { get; set; }
        public Seller ProductSeller { get; set; }

        public Guid OnSellId { get; set; }
        public Seller OnSell { get; set; }

并添加.OnDelete(DeleteBehavior.Restrict);背景關系

 protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Product>()
       .HasOne(p => p.ProductSeller)
       .WithMany(t => t.WaitingForShipping)
       .HasForeignKey(m => m.SellerId)
       .OnDelete(DeleteBehavior.Restrict);

            modelBuilder.Entity<Product>()
                .HasOne(p => p.OnSell)
                .WithMany(t => t.ProductsOnSell)
                .HasForeignKey(m => m.OnSellId)
                .OnDelete(DeleteBehavior.Restrict);


        }

它有效，我的 customer.cs 在下面。如果您的 Customer.cs 喜歡賣家，請像我一樣更改 Product 和 Context 中的代碼。

public class Customer
    {
        public int CustomerId { get; set; }
        public string CustomerName { get; set; }
      
       
        public ICollection<Product> BoughtProducts { get; set; }
       
    }

客戶更新

在背景關系中添加：

modelBuilder.Entity<Product>()
       .HasOne(p => p.ProductCustomer)
       .WithMany(t => t.WaitingForReceiving)
       .HasForeignKey(m => m.CustomerId)
       .OnDelete(DeleteBehavior.Restrict);

            modelBuilder.Entity<Product>()
                .HasOne(p => p.BoughtCustomer)
                .WithMany(t => t.BoughtProducts)
                .HasForeignKey(m => m.BoughtId)
                .OnDelete(DeleteBehavior.Restrict);

添加產品：

       public Guid CustomerId { get; set; }
       public Customer ProductCustomer { get; set; }
        
        public Guid BoughtId { get; set; }
        public Customer BoughtCustomer { get; set; }

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