anchor.diff:      Data1 = from_model(M),
       Data = maps:merge(OldData, Data1#{<<"_lastmodified_at">> => Time}),
       dets:insert(Table, {Id, Data}),
  -    close(Table).
  +    close(Table),
  +    ok.
   
   %% 部分更新
   patch(Table, M) ->
  
positive.code: 
  %% 更新数据，返回ok | notfound
  update(Table, M) ->
      Id = maps:get(value, proplists:get_value(<<"_key">>, M)),
      init(Table),
      OldData = from_model(get(Table, Id)),
  
negative.code: %% Data应为maps类型
  %% 自动插入创建和最后修改时间时间戳, 使用ISO标准格式
  create(Table, M) ->
      case ss_model:validate(M) of
          {ok, _} -> create2(Table, M);
          {error, M2} -> {error, M2}
      end.
  create2(Table, M) ->
      Id1 = maps:get(value, proplists:get_value(<<"_key">>, M, #{}), undefined),
      if
          Id1 =:= undefined ->
  