SET TERM ^ ;

create or alter procedure JOURNAL_USERINFO_PARAM_CAST (
    PARAM_VALUE varchar(256),
    TYPECAST smallint)
returns (
    PARAM_VALUE_CASTED varchar(256))
as
declare variable VALUE_INT bigint;
declare variable VALUE_FLOAT double precision;
declare variable VALUE_CHAR varchar(256);
begin
  begin
    if (typecast in (0, 3, 4, 5)) then value_int = cast(param_value as bigint);
    else if (typecast in (1, 6, 7, 8)) then value_float = cast(param_value as double precision);
    else value_char = param_value;

    select
      case :typecast
        when 0 then :value_int
        --при отображении чисел float убираем в конце лишние ноли, но оставляем минимум 2 знака после запятой (типа копейки)
        when 1 then iif(position('.',trim(trailing '0' from :value_float))>char_length(trim(trailing '0' from :value_float))-3, rpad(trim(trailing '0' from :value_float),2+position('.',trim(trailing '0' from :value_float)),'0'),trim(trailing '0' from :value_float))
        when 2 then :value_char
        when 3 then :value_int
        when 4 then :value_int
        when 5 then iif(:value_int=0, 'Изначально', cast('30.12.1899' as date)+:value_int)
        when 6 then iif(:value_float=0, 'Изначально', cast('30.12.1899 0:00' as timestamp)+:value_float)
        when 7 then iif(:value_float*24>10, cast(trunc(:value_float*24, 0) as integer), lpad(cast(trunc(:value_float*24, 0) as integer), 2, '0')) || ':' || lpad(mod(trunc(:value_float*24*60, 0), 60), 2,'0') || ':' || lpad(mod(trunc(:value_float*24*60*60, 0), 60), 2, '0')
        when 8 then iif(:value_float>10, cast(trunc(:value_float, 0) as integer), lpad(cast(trunc(:value_float, 0) as integer), 2, '0')) || ':' || lpad(mod(trunc(:value_float*60, 0), 60), 2,'0') || ':' || lpad(mod(trunc(:value_float*60*60, 0), 60), 2, '0')
      end
      from rdb$database
      into :param_value_casted;

    when sqlcode -413 do param_value_casted = '[value cast: conversion error] sqlcode='||sqlcode;
    when sqlcode -802 do param_value_casted = '[value cast: string truncation error] sqlcode='||sqlcode;
    when any do param_value_casted = '[value cast: unknown error] sqlcode='||sqlcode;
  end

  suspend;
end^

SET TERM ; ^