Question

我对EntityFramework，ASP.NET和MVC 5相对较新。

从这里开始遵循教程http://www.asp.net/mvc/tutorials/mvc-5/introduction/getting-started

我想通过添加Movie-Actor的一对多关系来扩展它（这是一个演员可以在很多电影中）。

因此我在我的Model文件夹中有这些代码：

Actor.cs

namespace MvcMovie.Models
{
    public class Actor
    {
        public int ActorId { get; set; }
        public String FirstName { get; set; }
        public String Address { get; set; }

        public ICollection<Movie> Movies { get; set; }
    }
}

Movie.cs

namespace MvcMovie.Models
{
    public class Movie
    {
        public int ID { get; set; }

        [StringLength(60, MinimumLength = 3)]
        public string Title { get; set; }

        [Display(Name = "Release Date")]
        [DataType(DataType.Date)]
        [DisplayFormat(DataFormatString = "{0:dd-MM-yyyy}", ApplyFormatInEditMode = true)]
        public DateTime ReleaseDate { get; set; }

        [RegularExpression(@"^[A-Z]+[a-zA-Z''-'\s]*$")]
        [Required]
        [StringLength(30)]
        public string Genre { get; set; }

        [Range(1, 100)]
        [DataType(DataType.Currency)]
        public decimal Price { get; set; }

        [RegularExpression(@"^[A-Z]+[a-zA-Z''-'\s]*$")]
        [StringLength(5)]
        public string Rating { get; set; }

        public int ActorId { get; set;}
        public Actor Actor { get; set; }
    }
}

MovieDBContext.cs

namespace MvcMovie.Models
{
    public class MovieDBContext : DbContext
    {
        public DbSet<Actor> Actors { get; set; }
        public DbSet<Movie> Movies { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Actor>().HasKey(p => p.ActorId);
            modelBuilder.Entity<Actor>().Property(c => c.ActorId)
                .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

            modelBuilder.Entity<Movie>().HasKey(m => m.ID);
            modelBuilder.Entity<Movie>().Property(m => m.ID)
                .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

            modelBuilder.Entity<Movie>().HasRequired(p => p.Actor)
                .WithMany(m => m.Movies)
                .HasForeignKey(m => m.ActorId);
            base.OnModelCreating(modelBuilder);
        }
    }
}

然后我在包管理器上尝试了以下命令

PM> Add-Migration ActorTable
PM> Update-Database

并收到以下错误： ALTER TABLE语句与FOREIGN KEY约束冲突＆＃34; FK_dbo.Movies_dbo.Actors_ActorId＆＃34;。冲突发生在数据库＆＃34; MOVIES_bd6a468e283a4100b6021adaf9911f7d＆＃34;，table＆＃34; dbo.Actors＆＃34;，column＆＃39; ActorId＆＃39;。

我感觉它与我的数据种子有关（在configuration.cs文件中）

protected override void Seed(MvcMovie.Models.MovieDBContext context)
        {
            context.Movies.AddOrUpdate(i => i.Title,
                new Movie
                {
                    Title = "When Harry Met Sally",
                    ReleaseDate = DateTime.Parse("1989-1-11"),
                    Genre = "Romantic Comedy",
                    Rating = "PG",
                    Price = 7.99M
                },

        }

有人可以建议我朝正确的方向发展。感谢

ps：我有MovieController及其相应的View设置（来自我在教程中所示的早期步骤）。

除了麦克的回答：

本文还包含有用的帮助，尤其是在添加迁移和更新数据库部分。

http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/creating-a-more-complex-data-model-for-an-asp-net-mvc-application

Answer 1

OnModelCreating中的以下行说明，Movie中需要Actor

modelBuilder.Entity<Movie>().HasRequired(p => p.Actor)
            .WithMany(m => m.Movies)
            .HasForeignKey(m => m.ActorId);

要成功更新数据库，您可以更改种子方法，如下所示：

context.Movies.AddOrUpdate(i => i.Title,
            new Movie
            {
                Title = "When Harry Met Sally",
                ReleaseDate = DateTime.Parse("1989-1-11"),
                Genre = "Romantic Comedy",
                Rating = "PG",
                Price = 7.99M,
                Actor = new Actor() { FirstName = "Actor1", Address = "Address1"}
            });

希望这有帮助。

使用EntityFramework和MVC 5进行CRUD操作

1 个答案: