FLOAT column becomes INT after being selected out

[arthurxie]

I have a table with float column(think it as a money balance column). For example,

CREATE TABLE account(..., balance float);
INSERT INTO account(..., balance) VALUES(..., 23.0);

The client calls web API to get the account detail, which returns a XML with the balance column formatted as: io_lib:format("~.2f", [Balance]). And the process will crash because the Balance is not a float.

I just checked the code and found the to_float function does not convert Num to float:

to_float(Data) ->
    {ok, [Num], _Leftovers} = case io_lib:fread("~f", binary_to_list(Data)) of
                                           % note: does not need conversion
        {error, _} ->
          case io_lib:fread("~d", binary_to_list(Data)) of  % note: does not need conversion
            {ok, [_], []} = Res ->
              Res;
            {ok, [X], E} ->
              io_lib:fread("~f", lists:flatten(io_lib:format("~w~s~s" ,[X,".0",E])))
          end
        ;
        Res ->
          Res
    end,
    Num.

As you see, some times a column will be transferred as int number text and parsed as io_lib:fread("~d", binary_to_list(Data)). So, I think this function should be like this:

to_float(Data) ->
    {ok, [Num], _Leftovers} = case io_lib:fread("~f", binary_to_list(Data)) of
                                           % note: does not need conversion
        {error, _} ->
          case io_lib:fread("~d", binary_to_list(Data)) of  % note: does not need conversion
            {ok, [_], []} = Res ->
              Res;
            {ok, [X], E} ->
              io_lib:fread("~f", lists:flatten(io_lib:format("~w~s~s" ,[X,".0",E])))
          end
        ;
        Res ->
          Res
    end,
    float(Num).