applicationuser 和自定义实体之间的一对多关系

Question

我收到一条错误消息，提示“ApplicationUser_Cars_Target: : Multiplicity is not valid in Role 'ApplicationUser_Cars_Target' in relationship 'ApplicationUser_Cars'。因为从属角色属性不是关键属性，所以从属角色的多重性上限必须是 '*'。 " 当我尝试更新我的数据库时，这是我的代码：

public class ApplicationUser : IdentityUser
{
    public string ProfilePicture { get;set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int PhoneNumber1 { get; set; }
    public int PhoneNumber2 { get; set; }
    public Address Address { get; set; }
    [ForeignKey("Cars")]
    public int CarId { get; set; }
    public ICollection<Car> Cars { get; set; }
}


public class Car
{
    [Key]
    public int CarId { get; set; }
    [ForeignKey("User")]
    public string ApplicationUserId { get; set; }
    public string Make { get; set; }
    public string Registration { get; set; }
    public string Color { get; set; }
    public string Model { get; set; }
    public string Year { get; set; }
    public string Type { get; set; }
    public virtual ApplicationUser User { get; set; }
}

这是我的流利的api要求......用户注册汽车应该是可选的

        modelBuilder.Entity<ApplicationUser>().HasKey(x => x.Id)
            .HasOptional(x => x.Cars);

Answer 1

我想通了，首先我必须使应用程序用户表中的外键可以为空，并向 fluentAPI 添加一个 .withMany() 方法，如下所示：

public class ApplicationUser : IdentityUser
{
    public string ProfilePicture { get;set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int PhoneNumber1 { get; set; }
    public int PhoneNumber2 { get; set; }
    public Address Address { get; set; }
    [ForeignKey("Cars")]
    public int? CarId { get; set; }
    public ICollection<Car> Cars { get; set; }
}

还有这个： modelBuilder.Entity().HasKey(x => x.Id) .HasOptional(x => x.Cars).withMany();