使用ApplicationDbContext使用OnModelCreating解析“无键定义”错误？ [英] Resolving 'No key Defined' errors while using OnModelCreating with ApplicationDbContext?

问题描述

我一直在为我的收藏类型创建导航属性，我发现的实例框架。我试图在我的MVC 5应用程序中尝试更新我的数据库时收到此错误：

I've been trying to create navigation properties for my collection types and I found this example of how one person accomplished it using OnModelCreating. I gave it a try in my MVC 5 application and I recieved this error when trying to update my database:

一个或多个验证错误是在模型生成期间检测到：

One or more validation errors were detected during model generation:

BlogEngine.Models.IdentityUserLogin：：EntityType'IdentityUserLogin'
没有定义键。定义此EntityType的键。
BlogEngine.Models.IdentityUserRole：：EntityType'IdentityUserRole'
没有定义键。定义此EntityType的键。
IdentityUserLogins：EntityType：EntitySet'IdentityUserLogins'是基于没有定义键的IdentityUserLogin类型的
。
IdentityUserRoles：EntityType：EntitySet'IdentityUserRoles'基于
类型'IdentityUserRole'，没有定义键。

BlogEngine.Models.IdentityUserLogin: : EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType. BlogEngine.Models.IdentityUserRole: : EntityType 'IdentityUserRole' has no key defined. Define the key for this EntityType. IdentityUserLogins: EntityType: EntitySet 'IdentityUserLogins' is based on type 'IdentityUserLogin' that has no keys defined. IdentityUserRoles: EntityType: EntitySet 'IdentityUserRoles' is based on type 'IdentityUserRole' that has no keys defined.

< h2>如何解决这些'没有键定义'错误？

我做了一些搜索，我发现这个解决方案为一个用户的问题，但他的需求是不同于我的。解决方案似乎是令人讨厌的，我正在尝试做的。

How do I resolve these 'No key Defined' errors?

I did some searching and I found this solution for one users problem, but his needs were different than mine. The solutions seemed pretty convoluted for what I am trying to do.

这是导致问题的代码：

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
    {
        public ApplicationDbContext()
            : base("DefaultConnection", throwIfV1Schema: false)
        {

        }
        //public DbSet<Image> Images { get; set; }

        public static ApplicationDbContext Create()
        {
            return new ApplicationDbContext();
        }

        public DbSet<Post> Posts { get; set; }
        public DbSet<Image> Images { get; set; }
        public DbSet<Album> Albums { get; set; }
        public DbSet<Tag> Tags { get; set; }

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

            modelBuilder.Entity<Post>().
                 HasOptional(e => e.Tags).
                 WithMany().
                 HasForeignKey(m => m.Tags_Id);

            modelBuilder.Entity<Tag>().
                 HasOptional(e => e.Posts).
                 WithMany().
                 HasForeignKey(m => m.Posts_Id);
        }

    }

许多关系：

Post.cs模型on Gist

Tag.cs Gist上的模型

更新以显示IdentityUser：

Update to show IdentityUser:

public class ApplicationUser : IdentityUser
    {
        public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
        {
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
            // Add custom user claims here
            return userIdentity;
        }
    }

推荐答案

你可能需要添加以下内容到 OnModelCreating

You might have to add something like the following to OnModelCreating

modelBuilder.Entity<IdentityUserLogin>().HasKey<string>(l => l.UserId);
modelBuilder.Entity<IdentityRole>().HasKey<string>(r => r.Id);
modelBuilder.Entity<IdentityUserRole>().HasKey(r => new { r.RoleId, r.UserId });

另请参阅：

• 地图在asp.net MVC5 EF6中使用流畅api的表


• 实体类型中的用户MVC5 EF6

• Map tables using fluent api in asp.net MVC5 EF6?
• User in Entity type MVC5 EF6

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