Erlang JSON验证问题

Question

I'm kinda new to erlang

trying to make JSON validation using https://github.com/Prots/olifer

but getting error:

1> sql_app:update(<<"0.2851">>,<<"frfrfrfr">>).

** exception error: no case clause matching [{<<"0.2851">>, <<"FORMAT_ERROR">>}] in function sql_app:update/2 (c:/sql/_build/default/lib/sql/src/sql_app.erl, line 31)

the function is:

update(Id, Info) ->
  case olifer:validate(Id, [{<<"string">>, <<"required">>}]) of
    {ok, _} ->  
    emysql:prepare(info, <<"UPDATE vobla SET info = ? WHERE id = ?">>),
      Result1 = emysql:execute(erlang, info, [Info, Id]),
      io:format("~n~p~n", [Result1]);
    {errors, _} -> io:format("~n~p~n", [error])
  end.

Could you please help me to figure it out.

thanks in advance.

Answer 1

It means that the case clause you have written does not match the result passed [{<<"0.2851">>, <<"FORMAT_ERROR">>}] . Your case clauses matches tuples of the format {ok, _} or {errors, _} . Not a list.

update(Id, Info) ->
  Res = olifer:validate(Id, [{<<"string">>, <<"required">>}]),
  io:format("~p", [Res]),
  case Res of
    [Tup] -> do_something; % could be an error
    {ok, _} ->  % validation success
    emysql:prepare(info, <<"UPDATE vobla SET info = ? WHERE id = ?">>),
      Result1 = emysql:execute(erlang, info, [Info, Id]),
      io:format("~n~p~n", [Result1]);
    {errors, _err} -> io:format("~n~p~n", [_err])
  end.

You are having a format error as per the log.