出现错误时但又找不到错误在哪里？可以尝试下面的，try catch语句，能清楚的找到error. 
    try
            {
                Repository<AllUsers> superAdmin = new Repository<AllUsers>(context);
                AllUsers usr = new AllUsers();
                usr.Id = "1";
                usr.Name = "admin";
                usr.Password = "sineva";
                usr.IsSuper = true;
                usr.Description = "系统内置";
                usr.IsRCurrent = true;
                superAdmin.Add(usr);
                context.SaveChanges();
                base.Seed(context);
            }
            catch(DbEntityValidationException ex)
            {
                 StringBuilder errors = new StringBuilder();
                IEnumerable<DbEntityValidationResult> validationResult = ex.EntityValidationErrors;
                foreach (DbEntityValidationResult result in validationResult)
                {
                    ICollection<DbValidationError> validationError = result.ValidationErrors;
                    foreach (DbValidationError err in validationError)
                    {
                        errors.Append(err.PropertyName + ":" + err.ErrorMessage + "\r\n");
                    }
                }
                    Console.WriteLine(errors.ToString());

            }