该属性必须是有效的实体类型,并且该属性应具有非抽象的getter和setter.实体框架

Question

我在实体框架中首先从代码创建数据库时遇到问题.我有以下三个类1 Person,2 PersonAddress,3 PersonEmploymentHistory如下所示.

namespace DataAccess.Models
{
[Table("Profile")]
public class Person
{
    [Key]
    public int UserId { get; set; }

    [Required(ErrorMessage = "Firstname is required")]
    public string PersonFirstName { get; set; }

    [Required(ErrorMessage = "Surname is required")]
    public string PersonSurname { get; set; }

    [Required(ErrorMessage = "Email is required")]
    [DataType(DataType.EmailAddress)]
    public string PersonEmail { get; set; }
    public int Age { get; set; }

    [Required(ErrorMessage = "Contact Number required")]
    public Int64 PersonNumber { get; set; }

    public bool IsActive { get; set; }

    [ForeignKey("AddressDetails")]
    public int AddressId { get; set; }
    public virtual PersonAddress AddressDetails { get; set; }

    [ForeignKey("EmploymentHistory")]
    public int EmployerId { get; set; }
    public virtual PersonEmploymentHistory EmploymentHistory { get; set; }

}
}

PersonAddress类

namespace DataAccess.Models
{
[Table("AddressDetails")]
public class PersonAddress
{
    [Key]
    public int AddressId { get; set; }

    [ForeignKey("UserId")]
    public int UserId { get; set; }

    [Required(ErrorMessage = "Address Line 1 required")]
    public string AddressLine1 { get; set; }

    [Required(ErrorMessage = "Address Line 2 required")]
    public string AddressLine2 { get; set; }

    [Required(ErrorMessage = "Postcode required")]
    [DataType(DataType.PostalCode)]
    public string PostCode { get; set; }
}
}

PersonEmploymentHistory

namespace DataAccess.Models
{
[Table("EmploymentHistory")]
public class PersonEmploymentHistory
{
    [Key]
    public int EmployerId { get; set; }
    public string EmployerName { get; set; }
    public decimal EmployeeSalary { get; set; }
    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }
    public string ReasonForLeaving { get; set; }

    [ForeignKey("UserId")]
    public int UserId { get; set; }
}
}

这是我的Context类

 public class Context : DbContext
{
    public Context()
        : base("DefaultConnection")
    {
        Database.SetInitializer<Context>(new CreateDatabaseIfNotExists<Context>());
    }

    public DbSet<Person> Person { get; set; }
    public DbSet<PersonAddress> PersonAddress { get; set; }
    public DbSet<PersonEmploymentHistory> PersonEmployment { get; set; }

}

现在我在创建外键等时遵循了教程但是当我运行我的项目并尝试将数据插入到人员表中时,我收到以下错误

无法将属性"UserId"配置为导航属性.该属性必须是有效的实体类型,并且该属性应具有非抽象的getter和setter.对于集合属性,类型必须实现ICollection,其中T是有效的实体类型.

Answer 1

我也是先学习代码.我使用的是流畅的API,所以我对注释没有经验.我认为你做外键的方式是错误的.我认为他们应该看起来像:

public int UserId { get; set; }
[ForeignKey("UserId")]
public virtual Person User{ get; set; }

区别在于你有一个FK类型的变量并注释它.您还可以查找流畅的API.

见http://www.codeproject.com/Articles/319366/EF-Code-First-Add-a-Foreign-Key-relationship