Question

我正在尝试创建一个(function () { const items = document.querySelector("#items"); const trigger = document.querySelector("#trigger"); const options = { root: null, rootMargin: "0px", threshold: 0.0 }; const observer = new IntersectionObserver((entries) => { entries.forEach((entry) => { if (entry.intersectionRatio > 0) { getMoreItems(15); items.appendChild(trigger); getMoreItems(5); } }); }, options); observer.observe(trigger); let itemcount = 0; getMoreItems(15); items.appendChild(trigger); getMoreItems(5); function getMoreItems(n) { for (let i = itemcount; i < itemcount + n; i++) { let item = document.createElement("p"); item.innerHTML = "this is item #" + i; items.appendChild(item); } itemcount += n; } })();作为子对象的ApplicationUser，这就是模型的样子：

ApplicationUser：

User

用户：

public class ApplicationUser : IdentityUser
{
  public User User { get; set; }
}

在我的DbContext中，我有：

public class User
{
   public int Id { get; set; }

   [ForeignKey("AspNetUser")]
   public string AspNetUserId { get; set; }

   public string FirstName { get; set; }

   public string LastName { get; set; }

   public virtual ApplicationUser AspNetUser { get; set; }
}

AdminConfiguration：

public class IdentityDbContext : IdentityDbContext<ApplicationUser>
{
   public IdentityDbContext(DbContextOptions<IdentityDbContext> options)
   : base(options)
   {
   }

   public DbSet<User> Users { get; set; }

   protected override void OnModelCreating(ModelBuilder builder)
   {
      base.OnModelCreating(builder);
      builder.ApplyConfiguration(new AdminConfiguration());
   }
}

使用此代码，我创建了一个迁移并尝试执行public class AdminConfiguration : IEntityTypeConfiguration<ApplicationUser> { public void Configure(EntityTypeBuilder<ApplicationUser> builder) { var id = "bc62cdff-77ca-4473-a467-210eb36fdd5d"; var admin = new ApplicationUser { Id = id, UserName = "admin", NormalizedUserName = "ADMIN", Email = "admin@dotvvm.com", NormalizedEmail = "ADMIN@DOTVVM.COM", EmailConfirmed = true, SecurityStamp = new Guid().ToString("D") }; admin.PasswordHash = GeneratePassword(admin, "Admin12345!"); builder.HasData(admin); builder.OwnsOne(a => a.User).HasData(new User { Id = 1, AspNetUserId = id, FirstName = "Test", LastName = "Test" }); } private string GeneratePassword(ApplicationUser user, string password) { var passHash = new PasswordHasher<ApplicationUser>(); return passHash.HashPassword(user, password); } }，但出现此错误： Update-Database

我不知道自己在做什么错，有人知道吗？

Answer 1

我几乎可以确定您使用的是.OwnsOne错误（但我怀疑这是根本原因，我稍后再谈）拥有的类型是Value对象。值对象本身没有身份，仅像其所有者的一部分一样存在

//this is entity, it has identity
public class Person
{
   public Guid Id { get; set; }
   public Name Name { get; set; }
}
//and this is value object and could be owned type
public class Name
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
}

如果您希望ApplicationUser和User都是实体（有意义），则可以考虑在它们之间建立一对一的关系，像这样

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<ApplicationUser>()
        .HasOne(a => a.User)
        .WithOne(b => b.ApplicationUser)
        .HasForeignKey<ApplicationUser>(b => b.AspNetUserId);
}

然后是您的

builder.HasData(new User
        {
          Id = 1,
          AspNetUserId = id,
          FirstName = "Test",
          LastName = "Test"
        });

可能有效，而...可能无效

因为您可能遇到的其他问题，可能是“自动增量ID”字段（在您的User类中是自动增量吗？）

如果是-

builder.OwnsOne(a => a.User).HasData(new User
        {
          Id = 1, //<<---- try removing this
          AspNetUserId = id,
          FirstName = "Test",
          LastName = "Test"
        });

这可以解决您的问题

使用EF播种数据

1 个答案: