实体框架的外键

Question

我有两个模型类User和Reclamation，Relamation类有一个User对象的外键，这是我的两个类：

public class User
{
    [Key, ScaffoldColumn(false), Display(Name = "ID User")]
    public int idUser { set; get; }

    [Required, StringLength(16), Display(Name = "Login")]
    public string login { set; get; }

    [Required, StringLength(16), Display(Name = "Password")]
    public string password { set; get; }
}

public class Reclamation
{
    [Key, ScaffoldColumn(false), Display(Name = "ID Reclamation")]
    public int idReclamation { set; get; }

    [ForeignKey("idUser")]
    public User user{ set; get; }

    [Required, Display(Name = "ID Rapporteur")]
    public int idUser { set; get; }

    [Required, StringLength(30), Display(Name = "Message")]
    public string message{ set; get; }
}

例如，假设我有一个idUser = 1的用户。 当我用idUser = 1创建一个新的Reclamation时，它将很好地插入数据库中，但是我的User对象问题不包含idUser = 1的用户信息，我应该在set Property中手动编码吗在Reclamation类上的idUser属性还是我遗漏了什么？

Answer 1

您应该尝试以下代码：

UserData.Include("Reclamation").ToList();

Answer 2

您可以将虚拟属性添加到实体类以启用延迟加载。 这样，您将启用EF在请求相关对象时加载它。

        public class User
        {
            [Key, ScaffoldColumn(false), Display(Name = "ID User")]
            public int idUser { set; get; }

            [Required, StringLength(16), Display(Name = "Login")]
            public string login { set; get; }

            [Required, StringLength(16), Display(Name = "Password")]
            public string password { set; get; }

            public virtual Reclamation Reclamation {get; set;}

            /*if you have one to many relationship, use Collection<T> 
   and initialize it in the constructor Reclamations = new Collection<Reclamation>();*/
            public virtual Collection<Reclamation> Reclamations {get; set;}
        }

如上所述，您的另一个选择是使用“急切加载”。 就像是：

context.Users.Include(x => x.Reclamations).ToList();