实体框架 - EF Code First选择外键

时间:2017-02-14 06:48:34

标签: entity-framework entity-framework-4 entity-framework-6 entity-framework-5 asp.net-mvc-5.2

型号:

public class Address
{
    [Key]
    public long AddressId { get; set; }

    public string Street { get; set; }

    public string Town { get; set; }

    public string State { get; set; }

    public string Country { get; set; }
}
public class User
{
    [Key]
    public long UserId { get; set; }

    public string UserName { get; set; }

    public string Password { get; set; }

    public virtual List<Address> Addresses { get; set; }
}

的DbContext:

public class DataModelContext : DbContext
{
        public DbSet<Address> Addresses { get; set; }
        public DbSet<User> Users{ get; set; }
}

使用上面的代码为DB创建这个模式。

Addresses          Users
-----------        -------
AddressId(PK)      UserId(PK)
Street             UserName 
Town               Password 
State  
Country 
User_UserId(FK)

现在我想从地址表中访问User_UserId,但它没有显示任何属性。给出错误“地址不包含User_UserId .....的定义

using (var db = new DataModelContext())
{
       db.Addresses.Select(x=>x.User_UserId).ToList();
}

1 个答案:

答案 0 :(得分:1)

创建模型时,使用外键关联代替独立关联。这意味着,您必须在模型中包含外键属性以及相应的导航属性。例如:

public class Address
{
    ...
    public int UserId {get; set;} //Foreign-Key property

    [ForeignKey("UserId")]
    public virtual User User { get; set; } // Navigational Property  
    ...
}

阅读this article了解详情。