.net core 将另一外键添加到ef core中的表设置中

我在ef的一个.net核心项目中工作。 我有两张桌子：

    public class Asset
    {
        [Key]
        public Guid Id { get; set; }
        
        public string Name { get; set; }
        public string Description { get; set; }
        
        // Relationships
        public ICollection<AssetMixRecord> AssetMixRecords { get; set; }
    }

    public class AssetMixRecord
    {        
        public decimal Percentage { get; set; }        
        public Guid AssetId { get; set; }

        // Relationships
        public Guid ParentAssetId { get; set; }
    }

我无法将第二个外键输入迁移代码。我应该手动添加它吗

谢谢和问候

---

请查看我的解决方案和完整的演示，它将生成以下迁移。我不确定是否可能有

DeleteBehavior.Cascade

这样的模式，EF迁移工具抱怨循环依赖

migrationBuilder.DropForeignKey(
    name: "FK_AssetMixRecords_Assets_AssetId",
    table: "AssetMixRecords");

migrationBuilder.AddForeignKey(
    name: "FK_AssetMixRecords_Assets_AssetId",
    table: "AssetMixRecords",
    column: "AssetId",
    principalTable: "Assets",
    principalColumn: "Id");

migrationBuilder.AddForeignKey(
    name: "FK_AssetMixRecords_Assets_ParentAssetId",
    table: "AssetMixRecords",
    column: "ParentAssetId",
    principalTable: "Assets",
    principalColumn: "Id");

下面是演示本身。请注意，

资产

中有两个导航属性。EF将根据其位置（AssetId或ParentAssetId）加载这些子实体

如果您将

AssetMixRecords

更改为

ParentAssetMixRecords

for

asset3

var dbContext = new ApplicationDbContext();
var asset1 = new Asset();
var asset2 = new Asset();

dbContext.Add(asset1);
dbContext.Add(asset2);
dbContext.SaveChanges();

var asset3 = new Asset();

asset3.ParentAssetMixRecords.Add(new AssetMixRecord()
{
    AssetId = asset1.Id,
    ParentAssetId = asset3.Id
});

asset3.ParentAssetMixRecords.Add(new AssetMixRecord()
{
    AssetId = asset2.Id,
    ParentAssetId = asset3.Id
});

dbContext.Add(asset3);
dbContext.SaveChanges();

---

嗨，Yegor，非常感谢你的努力。我从中得到了一些灵感，虽然这不是我想要的。例如，这个：//items，其中AssetMixRecord.AssetId==Id，将完全破坏我们的用例。这决不能发生，我们需要避免。好吧，别忘了发布您自己的解决方案作为答案：-）目前，解决方案似乎更遥远：公平地说，我不确定您为什么认为父资产id应该是迁移中的外键，如果在模型创建的

中没有提到它

我不确定是否理解您的评论。这是问题的一部分。如何将两个外键放入上下文定义中。

var asset1 = new Asset();
            var asset2 = new Asset();

            dbContext.Add(asset1);
            dbContext.Add(asset2);
            dbContext.SaveChanges();

            var asset3 = new Asset();

            asset3.AssetMixRecords.Add(new AssetMixRecord()
            {
                AssetId = asset1.Id,
                ParentAssetId = asset3.Id
            });

            asset3.AssetMixRecords.Add(new AssetMixRecord()
            {
                AssetId = asset2.Id,
                ParentAssetId = asset3.Id
            });

            dbContext.Add(asset3);
            dbContext.SaveChanges();

migrationBuilder.DropForeignKey(
    name: "FK_AssetMixRecords_Assets_AssetId",
    table: "AssetMixRecords");

migrationBuilder.AddForeignKey(
    name: "FK_AssetMixRecords_Assets_AssetId",
    table: "AssetMixRecords",
    column: "AssetId",
    principalTable: "Assets",
    principalColumn: "Id");

migrationBuilder.AddForeignKey(
    name: "FK_AssetMixRecords_Assets_ParentAssetId",
    table: "AssetMixRecords",
    column: "ParentAssetId",
    principalTable: "Assets",
    principalColumn: "Id");

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;

namespace ConsoleApp9
{
    public class Asset
    {
        [Key]
        public Guid Id { get; set; }

        public string Name { get; set; }
        public string Description { get; set; }

        // items where AssetMixRecord.AssetId == Id
        public ICollection<AssetMixRecord> AssetMixRecords { get; set; }

        // items where AssetMixRecord.ParentAssetId == Id
        public ICollection<AssetMixRecord> ParentAssetMixRecords { get; set; }
    }

    public class AssetMixRecord
    {
        public decimal Percentage { get; set; }
        public Guid AssetId { get; set; }
        public virtual Asset Asset { get; set; }
        public Guid ParentAssetId { get; set; }
        public virtual Asset ParentAsset { get; set; }
    }

    public class ApplicationDbContext : DbContext
    {
        public DbSet<Asset> Assets { get; set; }
        public DbSet<AssetMixRecord> AssetMixRecords { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer("Server=DESKTOP-1111111;Database=testef11db;Integrated Security=true;");

            base.OnConfiguring(optionsBuilder);
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Asset>()
                .HasMany(a => a.AssetMixRecords)
                .WithOne(x => x.Asset)
                .HasForeignKey(x => x.AssetId)
                .OnDelete(DeleteBehavior.NoAction);

            modelBuilder.Entity<Asset>()
                .HasMany(x => x.ParentAssetMixRecords)
                .WithOne(x => x.ParentAsset)
                .HasForeignKey(x => x.ParentAssetId)
                .OnDelete(DeleteBehavior.NoAction);

            modelBuilder.Entity<AssetMixRecord>()
                .HasKey(c => new { c.ParentAssetId, c.AssetId })
                .IsClustered();

            base.OnModelCreating(modelBuilder);
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            var dbContext = new ApplicationDbContext();

            var asset1 = new Asset();
            var asset2 = new Asset();

            dbContext.Add(asset1);
            dbContext.Add(asset2);
            dbContext.SaveChanges();

            var assetDataMixRecord = new AssetMixRecord()
            {
                AssetId = asset1.Id,
                ParentAssetId = asset2.Id
            };

            dbContext.Add(assetDataMixRecord);
            dbContext.SaveChanges();

            var assets = dbContext.Assets
                .Include(x => x.AssetMixRecords)
                .Include(x => x.ParentAssetMixRecords)
                .ToList();
        }
    }
}

modelBuilder.Entity<AssetMixRecord>()
    .HasCheckConstraint("PK_Check_ChildAssetId_And_ParentAssetId", "ParentAssetId != ChildAssetId");

var dbContext = new ApplicationDbContext();
var asset1 = new Asset();
var asset2 = new Asset();

dbContext.Add(asset1);
dbContext.Add(asset2);
dbContext.SaveChanges();

var asset3 = new Asset();

asset3.ParentAssetMixRecords.Add(new AssetMixRecord()
{
    AssetId = asset1.Id,
    ParentAssetId = asset3.Id
});

asset3.ParentAssetMixRecords.Add(new AssetMixRecord()
{
    AssetId = asset2.Id,
    ParentAssetId = asset3.Id
});

dbContext.Add(asset3);
dbContext.SaveChanges();