Question

在一种业务场景中，需要使用代码优先方法创建模型，例如企业有很多供应商
供应商可以属于许多企业因此需要在业务和供应商之间创建很多对很多的供应商，但是供应商在逻辑上是业务本身（自我参考）。供应商模型实际上并不存在。

如何创建与Business本身具有多对多关系并且在关联表（即BusinessVendor）中具有独立列IsActive和VendorType的BusinessVendor模型？

更新：

    public class Business
    {
        public Business()
        {
            this.Users = new HashSet<User>();
            this.Departments = new HashSet<Department>();
            this.Addresses = new HashSet<Address>();            
            this.BusinessProducts = new HashSet<BusinessProduct>();
            this.Vendors = new HashSet<Vendor>();
        }

        [Key]
        public int BusinessId { get; set; }

        [Required]
        [Display(Name = "Business Name")]
        public string Name { get; set; }

        [Required]
        [Display(Name = "PAN Number")]
        public string PAN { get; set; }

        [Required]
        [DataType(DataType.EmailAddress)]
        [RegularExpression(@"[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}", ErrorMessage = "Incorrect Email Format")]
        public string Email { get; set; }

        public string Fax { get; set; }

        [Required]
        [Display(Name = "Registration Number")]
        public string RegistrationNumber { get; set; }

        [Required]
        [Display(Name ="Business ID")]
        public string DisplayName { get; set; }     

        public virtual ICollection<Address> Addresses { get; set; }
        public virtual ICollection<User> Users { get; set; }
        public virtual ICollection<Department> Departments { get; set; }        

        public virtual ICollection<BusinessProduct> BusinessProducts { get; set; }

        public virtual ICollection<CategoryOfProduct> ProductCategories { get; set; }

        public virtual ICollection<Vendor> Vendors { get; set; }

    }

public class Vendor
    {

        [Key]
        public int VendorId { get; set; }

        [Required, ForeignKey("Client")]
        public int BusinessId { get; set; }     

        public int VendorTypeId { get; set; }

        [ForeignKey("VendorTypeId")]
        public virtual VendorType VendorType { get; set; }

        public bool IsActive { get; set; }

        public virtual Business Client { get; set; }

        public virtual ICollection<Business> Businesses { get; set; }


    }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
modelBuilder.Entity<Business>()
                  .HasMany(c => c.Vendors)
                  .WithMany(c => c.Businesses)                
                  .Map(op =>
                  {
                      op.MapLeftKey("BusinessId");
                      op.MapRightKey("VendorId");
                      op.ToTable("BusinessVendors");                      
                  });

}

但现在级联删除的问题为

介绍FOREIGN KEY约束桌子上的'FK_dbo.BusinessVendors_dbo.Vendors_VendorId' “ BusinessVendors”可能会导致循环或多个级联路径。指定 ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他FOREIGN 关键约束。无法创建约束。查看以前的错误。

EF代码优先自我参考

0 个答案: