实体框架代码首先自引用有效负载的父子 [英] Entity Framework Code First Self Referencing Parent Child with Payload

问题描述

我试图在实体框架中首先使用代码进行设置，并遇到困难。描述我想要完成的工作：

拥有一个Product的实体。该产品可选地可以具有一个或多个相关的小孩产品。一个产品可以是一个或多个母产品的孩子。

当我去生成一个绑定到模型类产品的控制器时，我收到一个错误：（更新，更具体地说，匹配下面的代码） p>

 运行所选代码生成器时出错：
'无法检索 ProductCatalog.Models.Product。 
不支持每种类型的多个对象集。对象集
'Product'和'Products'都可以包含类型为
'ProductCatalog.Models.Product'的实例。 
  

这里是不工作的模型类：

 使用System.Collections.Generic; 
使用System.ComponentModel.DataAnnotations; 
使用System.ComponentModel.DataAnnotations.Schema; 
使用System.Data.Entity; 
 
命名空间ProductCatalog.Models 
 {
 //产品
 public class Product 
 {
 [Key] 
 public int ProductId {get;组; } // ProductID（主键）
 public string ProductName {get;组; } // ProductName 
 public string ProductSku {get;组; } // ProductSKU 
 public int BaseQuantity {get;组; } // BaseQuantity 
 public decimal BaseCost {get;组; } // BaseCost 
 
 //反向导航
 public virtual ICollection< RelatedProduct> ParentProducts {get;组; } // RelatedProduct.FK_RelatedProductChildID 
 public virtual ICollection< RelatedProduct>儿童产品{get;组; } // RelatedProduct.FK_RelatedProductParentID 
 
 public virtual ICollection< RelatedProduct>相关产品{get;组; 
 
 
 
 //相关产品
 public class RelatedProduct 
 {
 [Key，Column（Order = 0）] 
 public int ParentId {get;组; } // ParentID 
 [Key，Column（Order = 1）] 
 public int ChildId {get;组; } // ChildID 
 public int Quantity {get;组; } //数量
 public bool必需{get;组; } //必需
 public bool Locked {get;组; } //锁定
 
 //外键
 public virtual Product ParentProduct {get;组; } // FK_RelatedProductParentID 
 public virtual Product ChildProduct {get;组; } // FK_RelatedProductChildID 
} 
 
 public class ProductDBContext：DbContext 
 {
 public IDbSet< Product>产品{get;组; } // Product 
 public IDbSet< RelatedProduct>相关产品{get;组; } //相关产品
 
 protected override void OnModelCreating（DbModelBuilder modelBuilder）
 {
 base.OnModelCreating（modelBuilder）; 
 
 modelBuilder.Entity< RelatedProduct>（）
 .HasRequired（a => a.ParentProduct）
 .WithMany（b => b.ChildProducts）
 .HasForeignKey（c => c.ParentId）// FK_RelatedProductParentID 
 .WillCascadeOnDelete（false）; 
 
 modelBuilder.Entity< RelatedProduct>（）
 .HasRequired（a => a.ChildProduct）
 .WithMany（b => b.ParentProducts）
 .HasForeignKey（c => c.ChildId）; // FK_RelatedProductChildID 
 
} 
} 
} 
  

通过使用System.Collections.Generic复用DbSets

  
使用System.ComponentModel.DataAnnotations; 
使用System.ComponentModel.DataAnnotations.Schema; 
使用System.Data.Entity; 
 
命名空间ProductCatalog.Models 
 {
 //产品
 public class Product 
 {
 [Key] 
 public int ProductId {get;组; } // ProductID（主键）
 public string ProductName {get;组; } // ProductName 
 public string ProductSku {get;组; } // ProductSKU 
 public int BaseQuantity {get;组; } // BaseQuantity 
 public decimal BaseCost {get;组; } // BaseCost 
 
 //反向导航
 public virtual ICollection< RelatedProduct> ParentProducts {get;组; } // RelatedProduct.FK_RelatedProductChildID 
 public virtual ICollection< RelatedProduct>儿童产品{get;组; } // RelatedProduct.FK_RelatedProductParentID 
 
 public virtual ICollection< RelatedProduct>相关产品{get;组; 
 
 
 
 //相关产品
 public class RelatedProduct 
 {
 [Key，Column（Order = 0）] 
 public int ParentId {get;组; } // ParentID 
 [Key，Column（Order = 1）] 
 public int ChildId {get;组; } // ChildID 
 public int Quantity {get;组; } //数量
 public bool必需{get;组; } //必需
 public bool Locked {get;组; } //锁定
 
 //外键
 public virtual Product ParentProduct {get;组; } // FK_RelatedProductParentID 
 public virtual Product ChildProduct {get;组; } // FK_RelatedProductChildID 
} 
 
 public class ProductDBContext：DbContext 
 {
 public IDbSet< Product>产品{get;组; } // Product 
 public IDbSet< RelatedProduct>相关产品{get;组; } //相关产品
 
 protected override void OnModelCreating（DbModelBuilder modelBuilder）
 {
 base.OnModelCreating（modelBuilder）; 
 
 modelBuilder.Entity< RelatedProduct>（）
 .HasRequired（a => a.ParentProduct）
 .WithMany（b => b.ChildProducts）
 .HasForeignKey（c => c.ParentId）// FK_RelatedProductParentID 
 .WillCascadeOnDelete（false）; 
 
 modelBuilder.Entity< RelatedProduct>（）
 .HasRequired（a => a.ChildProduct）
 .WithMany（b => b.ParentProducts）
 .HasForeignKey（c => c.ChildId）; // FK_RelatedProductChildID 
 
} 
} 
} 
  

I'm attempting to set this up using code first in entity framework and am running into difficulty. To describe what i'm trying to accomplish:

Have an entity of Product. This product optionally may have one or more related "child" products. A product can be the child to one or more parent products.

when I go to generate a controller tied to the model class "Product", i'm getting an error: (updated, more specific, matches code below)

 There was an error running the selected code generator:
'Unable to retrieve metadata for 'ProductCatalog.Models.Product'.
 Multiple object sets per type are not supported. The object sets 
'Product' and 'Products' can both contain instances of type
'ProductCatalog.Models.Product'.

here's the not working model class:

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;

namespace ProductCatalog.Models
{
    // Product
    public class Product
    {
        [Key]
        public int ProductId { get; set; } // ProductID (Primary key)
        public string ProductName { get; set; } // ProductName
        public string ProductSku { get; set; } // ProductSKU
        public int BaseQuantity { get; set; } // BaseQuantity
        public decimal BaseCost { get; set; } // BaseCost

        // Reverse navigation
        public virtual ICollection<RelatedProduct> ParentProducts { get; set; } // RelatedProduct.FK_RelatedProductChildID
        public virtual ICollection<RelatedProduct> ChildProducts { get; set; } // RelatedProduct.FK_RelatedProductParentID

        public virtual ICollection<RelatedProduct> RelatedProducts { get; set; }
    }


    // RelatedProduct
    public class RelatedProduct
    {
        [Key, Column(Order = 0)]
        public int ParentId { get; set; } // ParentID
        [Key, Column(Order = 1)]
        public int ChildId { get; set; } // ChildID
        public int Quantity { get; set; } // Quantity
        public bool Required { get; set; } // Required
        public bool Locked { get; set; } // Locked

        // Foreign keys
        public virtual Product ParentProduct { get; set; } //  FK_RelatedProductParentID
        public virtual Product ChildProduct { get; set; } //  FK_RelatedProductChildID
    }

    public class ProductDBContext : DbContext
    {
        public IDbSet<Product> Product { get; set; } // Product
        public IDbSet<RelatedProduct> RelatedProduct { get; set; } // RelatedProduct

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<RelatedProduct>()
                .HasRequired(a => a.ParentProduct)
                .WithMany(b => b.ChildProducts)
                .HasForeignKey(c => c.ParentId) // FK_RelatedProductParentID
                .WillCascadeOnDelete(false);

            modelBuilder.Entity<RelatedProduct>()
                .HasRequired(a => a.ChildProduct)
                .WithMany(b => b.ParentProducts)
                .HasForeignKey(c => c.ChildId); // FK_RelatedProductChildID

        }
    }
}

解决方案

fixed by pluralizing the DbSets

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;

namespace ProductCatalog.Models
{
    // Product
    public class Product
    {
        [Key]
        public int ProductId { get; set; } // ProductID (Primary key)
        public string ProductName { get; set; } // ProductName
        public string ProductSku { get; set; } // ProductSKU
        public int BaseQuantity { get; set; } // BaseQuantity
        public decimal BaseCost { get; set; } // BaseCost

        // Reverse navigation
        public virtual ICollection<RelatedProduct> ParentProducts { get; set; } // RelatedProduct.FK_RelatedProductChildID
        public virtual ICollection<RelatedProduct> ChildProducts { get; set; } // RelatedProduct.FK_RelatedProductParentID

        public virtual ICollection<RelatedProduct> RelatedProducts { get; set; }
    }


    // RelatedProduct
    public class RelatedProduct
    {
        [Key, Column(Order = 0)]
        public int ParentId { get; set; } // ParentID
        [Key, Column(Order = 1)]
        public int ChildId { get; set; } // ChildID
        public int Quantity { get; set; } // Quantity
        public bool Required { get; set; } // Required
        public bool Locked { get; set; } // Locked

        // Foreign keys
        public virtual Product ParentProduct { get; set; } //  FK_RelatedProductParentID
        public virtual Product ChildProduct { get; set; } //  FK_RelatedProductChildID
    }

    public class ProductDBContext : DbContext
    {
        public IDbSet<Product> Products { get; set; } // Product
        public IDbSet<RelatedProduct> RelatedProducts { get; set; } // RelatedProduct

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<RelatedProduct>()
                .HasRequired(a => a.ParentProduct)
                .WithMany(b => b.ChildProducts)
                .HasForeignKey(c => c.ParentId) // FK_RelatedProductParentID
                .WillCascadeOnDelete(false);

            modelBuilder.Entity<RelatedProduct>()
                .HasRequired(a => a.ChildProduct)
                .WithMany(b => b.ParentProducts)
                .HasForeignKey(c => c.ChildId); // FK_RelatedProductChildID

        }
    }
}

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