一对多流畅的实体框架

Question

每半小时后，将收到来自移动设备的请求。验证手机在设备表中可用，然后将记录添加到 Ping 表中。使用实体框架将相同的表映射到数据库。

谁能告诉我如何将 Device.Id（主键）映射到 Ping.IdDevice（外键），使用 Fluent Api 的关系将是一对多的。

public class Ping 
{
    public long Id { get; set; }
    public long IdDevice { get; set; }
    public string Request { get; set; }
    public string Response { get; set; }
    public int RspCode { get; set; }
    public DateTime CreatedDateTime { get; set; }
}

    public class Device {
    public long Id { get; set; }
    public string Uid { get; set; }
    public Type Type { get; set; }
    public Status Status { get; set; }
}

        protected override void OnModelCreating(DbModelBuilder modelBuilder) {

        modelBuilder.Entity<Device>().HasKey(d => d.Id);
        modelBuilder.Entity<Device>().Property(d => d.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);


        modelBuilder.Entity<Device>().Property(d => d.Uid).HasMaxLength(8);
        modelBuilder.Entity<Device>().HasRequired(d => d.Uid);

        modelBuilder.Entity<Ping>().HasKey(p => p.Id);
        modelBuilder.Entity<Ping>().Property(p => p.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);



        base.OnModelCreating(modelBuilder);
    }

Answer 1

您可以尝试在 Ping 类中为 Device 添加一个导航属性，如下所示：

public class Ping
{
    public long Id { get; set; }
    public long IdDevice { get; set; }
    public virtual Device Device { get; set; }//Newly added
    public string Request { get; set; }
    public string Response { get; set; }
    public int RspCode { get; set; }
    public DateTime CreatedDateTime { get; set; }
}

然后在 Device 类中为 Pings 添加导航属性，如下所示

public class Device
{
    public long Id { get; set; }
    public string Uid { get; set; }
    public Type Type { get; set; }
    public Status Status { get; set; }
    public virtual List<Ping> Pings { get; set; } //Newly added
}

最后在 OnModelCreating 中添加如下映射：

modelBuilder.Entity<Device>().HasMany(d => d.Pings).WithRequired(p => p.Device).HasForeignKey(p => p.IdDevice);