EF 关系描述

网络上常常看到有ef 1对1 1对多等关系的描述，按照我的理解，其根本就是为了呈现出一个视图，我最近设计了一个ef关系，请大家看一看。

需求描述

在gps车辆信息管理中，有个开户需求，其根本就是三种关系的对应，车辆信息，sim卡信息，以及终端信息，这三个实体是一一对应的，一旦开户，就需要三种信息。

先设计三种关系实体

    /// <summary>
    /// 实体模型抽象类
    /// </summary>
    public abstract class DbSetBase : IDbSetBase
    {
        /// <summary>
        /// 构造函数
        /// </summary>
        public DbSetBase()
        {
            Id = Guid.NewGuid();
            CreatedDate = DateTime.Now;
            Deleted = false;
        }
        /// <summary>
        /// 唯一Id
        /// </summary>
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public Guid Id { get; set; }
        /// <summary>
        /// 创建时间
        /// </summary>
        public DateTime CreatedDate { get; set; }
        /// <summary>
        /// 更新时间
        /// </summary>
        public DateTime? UpdatedDate { get; set; }
        /// <summary>
        /// 是否删除
        /// </summary>
        public bool Deleted { get; set; }
        /// <summary>
        /// 备注
        /// </summary>
        public string Remark { get; set; }
    }

    /// <summary>
    /// 车辆数据
    /// </summary>
    [Table("S_VehicleInfo")]
    public class VehicleInfo : DbSetBase
    {
        /// <summary>
        /// 车牌号
        /// </summary>
        public string VehicleNo { get; set; }
        /// <summary>
        /// 车牌颜色
        /// </summary>
        public VehicleColor Color { get; set; }
        /// <summary>
        /// 企业信息
        /// </summary>
        public Guid EnterpriseId { get; set; }
        /// <summary>
        /// 企业信息
        /// </summary>
        [ForeignKey("EnterpriseId")]
        public virtual Enterprise Enterprise { get; set; }
        /// <summary>
        /// 使用状态
        /// </summary>
        public UsingType UsingType { get; set; }
        /// <summary>
        /// 开户信息
        /// </summary>
        public virtual OpenAccount Account { get; set; }
        /// <summary>
        /// 所属车队
        /// </summary>
        public Guid? CompanyId { get; set; }
        /// <summary>
        /// 所属车队
        /// </summary>
        [ForeignKey("CompanyId")]
        public virtual Company Company { get; set; }
    }

    /// <summary>
    /// 终端信息
    /// </summary>
    [Table("S_TerminalInfo")]
    public class TerminalInfo : DbSetBase
    {
        /// <summary>
        /// 终端Id
        /// </summary>
        public string TerminalNo { get; set; }
        /// <summary>
        /// 终端类型
        /// </summary>
        public string TerminalType { get; set; }
        /// <summary>
        /// 使用状态
        /// </summary>
        public UsingType UsingType { get; set; }
        /// <summary>
        /// 开户信息
        /// </summary>
        public virtual OpenAccount Account { get; set; }
    }

    /// <summary>
    /// Sim信息
    /// </summary>
    [Table("S_SimInfo")]
    public class SimInfo : DbSetBase
    {
        /// <summary>
        /// 手机号
        /// </summary>
        public string PhoneNo { get; set; }
        /// <summary>
        /// Sim卡号
        /// </summary>
        public string SimNo { get; set; }
        /// <summary>
        /// 使用状态
        /// </summary>
        public UsingType UsingType { get; set; }
        /// <summary>
        /// 开户信息
        /// </summary>
       public virtual OpenAccount Account { get; set; }
    }

    /// <summary>
    /// 开户信息
    /// </summary>
    [Table("OpenAccount")]
    public class OpenAccount : DbSetBase
    {
        /// <summary>
        ///  终端信息
        /// </summary>
        public virtual TerminalInfo Terminal { get; set; }

        /// <summary>
        /// 车辆信息
        /// </summary>
        public virtual VehicleInfo Vehicle { get; set; }

        /// <summary>
        /// Sim信息
        /// </summary>
        public virtual SimInfo Sim { get; set; }

        /// <summary>
        /// 注册时间
        /// </summary>
        public DateTime? RegisterTime { get; set; }

        /// <summary>
        /// 是否注册
        /// </summary>
        public bool? IsRegister { get; set; }
    }
}

，在通过 Fluent Api设计其对应关系：

 modelBuilder.Entity<OpenAccount>().HasRequired(a => a.Vehicle).WithOptional(b => b.Account).Map(m => m.MapKey("VehicleId"));
 modelBuilder.Entity<OpenAccount>().HasRequired(a => a.Sim).WithOptional(b => b.Account).Map(m => m.MapKey("SimId"));
 modelBuilder.Entity<OpenAccount>().HasRequired(a => a.Terminal).WithOptional(b => b.Account).Map(m => m.MapKey("TerminalId"));

这样三种对象的对应关系就完成了，开户信息表就是作为一种视图来呈现三种对象的对应。