c# - Entity Framework 代码优先要求的外键

Question

我正在为一个电子商务项目首先使用代码，

我有 2 个类:类别和产品

关系是一对多，Category有很多产品，我想根据需要制作外键(不为空)，因此，如果我添加产品，我必须输入 categoryid。

当我这样做时，我得到这个错误:

Introducing FOREIGN KEY constraint 'FK_dbo.Products_dbo.Categories_categoryId' on table 'Products' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.

有什么想法吗？

public class Category :IObjectWithState
{
    [Key]
    public int CategoryId { get; set; }
    [Required]
    public string Discription { get; set; }
    public string Notes { get; set; }
    public int ParentCategoryId { get; set; }

    public virtual ICollection<Product> Products { get; set; }
    public virtual ICollection<Discount> Discounts { get; set; }
    public virtual ICollection<ProductList> ProductLists { get; set; }

    [NotMapped]
    public State state { get; set; }
}

public class Product :IObjectWithState
{
    [Key]
    public int ProductId { get; set; }
    [Required]
    public string ProductName { get; set; }
    [Required]
    public string ShortDiscription { get; set; }
    public string LongDiscription { get; set; }

     [Required]
    public bool Active { get; set; }

    [Required]
    public int categoryId { get; set; }
    [ForeignKey("categoryId")]
    public  Category Category { get; set; }

    public ICollection<ProductImage> ProductImage { get; set; }
    public ICollection<Discount> Discount { get; set; }
    public ICollection<Discussion> Duscussion { get; set; }
    public ICollection<ProductAttributeValue> ProductAttributeValue { get; set; }
    public ICollection<ProductListItem> ProductListItem { get; set; }
    public ICollection<ProductSKU> ProductSKU { get; set; }
    public ICollection<RelatedProduct> RelatedProduct { get; set; }
    public ICollection<Review> Review { get; set; }
    public ICollection<ShoppingCart> ShoppingCart { get; set; }
}

Answer 1

我在 Migration 类中将 cascadeDelete: 设置为 false