INSERT语句与FOREIGN KEY约束冲突。该语句已终止

Question

我有一个希望在我的应用程序中运行OnModelCreating方法时运行的迁移种子数据。

部分数据用于这两个实体-State和LGA，所以除了我的其他行外，我还有这两行

protected override void OnModelCreating(ModelBuilder modelBuilder)

ApplicationDbContext中的方法。

 ...
 public DbSet<State> States { get; set; }
 public DbSet<LGA> LGAs { get; set; }
 ...

并且我有一个方法Seed()，这是一个扩展方法，我希望运行该方法来播种两个表。

我按如下方式调用Seed()方法：

modelBuilder.Seed();

扩展方法定义如下：

public static class ModelBuilderExtensions
{
    public static void Seed(this ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<State>().HasData(
                new State { Id = 1, Name = "Abia" },
                new State { Id = 2, Name = "Adamawa" },
                new State { Id = 3, Name = "Akwa Ibom" },
                new State { Id = 4, Name = "Anambra" },
                new State { Id = 5, Name = "Bauchi" },
                new State { Id = 6, Name = "Bayelsa" },
                new State { Id = 7, Name = "Benue" },
                new State { Id = 8, Name = "Borno" },
                new State { Id = 9, Name = "Cross River" },
                new State { Id = 10, Name = "Delta" },
                new State { Id = 11, Name = "Ebonyi" },
                new State { Id = 12, Name = "Edo" },
                new State { Id = 13, Name = "Ekiti" },
                new State { Id = 14, Name = "Enugu" },
                new State { Id = 15, Name = "Gombe" },
                new State { Id = 16, Name = "Imo" },
                new State { Id = 17, Name = "Jigawa" },
                new State { Id = 18, Name = "Kaduna" },
                new State { Id = 19, Name = "Kano" },
                new State { Id = 20, Name = "Katsina" },
                new State { Id = 21, Name = "Kebbi" },
                new State { Id = 22, Name = "Kogi" },
                new State { Id = 23, Name = "Kwara" },
                new State { Id = 24, Name = "Lagos" },
                new State { Id = 25, Name = "Nasarawa" },
                new State { Id = 26, Name = "Niger" },
                new State { Id = 27, Name = "Ogun" },
                new State { Id = 28, Name = "Ondo" },
                new State { Id = 29, Name = "Osun" },
                new State { Id = 30, Name = "Oyo" },
                new State { Id = 31, Name = "Plateau" },
                new State { Id = 32, Name = "Rivers" },
                new State { Id = 33, Name = "Sokoto" },
                new State { Id = 34, Name = "Taraba" },
                new State { Id = 35, Name = "Yobe" },
                new State { Id = 36, Name = "Zamfara" },
                new State { Id = 37, Name = "Abuja (FCT)" },
                new State { Id = 38, Name = "Non Nigerian" }
                );

        modelBuilder.Entity<LGA>().HasData(
            new LGA { Id = 1, StateId = 1, Name = "Aba North" },
            new LGA { Id = 2, StateId = 1, Name = "Aba South" },
            new LGA { Id = 3, StateId = 1, Name = "Arochukwu" },
            ...
            new LGA { Id = 784, StateId = 16, Name = "Ahiazu - Mbaise" },
            new LGA { Id = 785, StateId = 38, Name = "Foreign" },
            new LGA { Id = 786, StateId = 18, Name = "Kaduna South" },
            new LGA { Id = 787, StateId = 16, Name = "Aboh - Mbaise" },
            new LGA { Id = 788, StateId = 9, Name = "Odukpani" }

这是两个实体之间的关系

public class LGA
{
    public int Id { get; set; }
    [Display(Name="State")]
    public int StateId { get; set; }
    [Required]
    public string Name { get; set; }

    public ICollection<Town> Towns { get; set; }
    [ForeignKey("StateId")]
    public State State { get; set; }

    public ICollection<ApplicationUser> Residents { get; set; }
}


public class State
{
    public int Id { get; set; }
    [Required]
    public string Name { get; set; }
    [Display(Name="State Code")]
    public string Code { get; set; }

    public ICollection<LGA> LGAs { get; set; }
    public ICollection<ApplicationUser> Residents { get; set; }
}

但是当我运行update-database时，出现以下错误：

INSERT语句与FOREIGN KEY约束“ FK_LGAs_States_StateId”冲突。数据库...表“ dbo.States”的列“ Id”中发生了冲突。

并且我已经确保所有状态都包含在迁移代码中。

但是，我意识到当我检查生成的States表时，即使在数据种子代码中存在该行，我似乎也找不到该行的最后一行

我正在Windows 10操作系统上运行带有Entity Framework Core的ASP.NET Core 2.2。>

请问我哪里出问题了？

谢谢您的协助。

我有一个希望在应用程序中运行OnModelCreating方法时运行的迁移种子数据。部分数据用于这两个实体-State和LGA，因此我在...

Answer 1

更改外键约束名称。会起作用。

Answer 2

我刚刚通过以下更改在数据库上测试了您的实体，并且一切正常。