报错的可能原因可能是EF的映射关系出了问题,如果Class之间有关联,需要手动设置好表关系
如:一个User有多个Device,一个Device可能属于多个User
public partial class User { [Key] public int ID { get; set; } public string UserName { get; set; } public virtual ICollectionUserDeivces { get; set; } } public partial class Device { [Key] public int id { get; set; } public string deviceName { get; set; } public virtual ICollection UserDeivces { get; set; } } public class UserDeivce { [Key] public int ID { get; set; } public int UserID { get; set; } public int DeivceID { get; set; } public virtual Model.User User { set; get; } public virtual Model.Device Device { set; get; } } protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity () .HasRequired(a => a.Device) .WithMany(a => a.UserDeivces) .HasForeignKey(a => a.DeviceID); modelBuilder.Entity () .HasRequired(a => a.User) .WithMany(a => a.UserDeivces) .HasForeignKey(a => a.UserID); }