Column Function Return Type Number is forcing to cast to Decimal

Question

Hi - I am using Oracle 11g Release 11.2.0.2.0 and ODP.NET 4.112.3.0.
Whenever I am trying to execute a package query with column function and return type is number, it is throwing cast exception whenever I am trying to cast it as GetInt32.
The workaround we have for now is to get it decimal and cast to Int32, this is going to be painful moving forward because it means that we have to check each of our packages and need to know if each package has column function and do this special casting.
Is this a known bug?

Answer 1

Oracle Number is 6.
Run the below script to your machine and the sample code below so you can see what I am talking about.
--drop table aninalfarm;
--drop table birdfarm;
--drop public synonym animalfarm;
--drop public synonym birdfarm;
--drop public synonym birdfarm_Pkg;
--drop public synonym animalfarm_Pkg;
create table animalfarm
        (code                                 NUMBER(6),
        description                        varchar2(10));
create table birdfarm
       (code                               number(6),
       description                         varchar2(10));
create public synonym  animalfarm for db.animalfarm;
create public synonym  birdfarm for db.birdfarm;
grant select, delete, insert, update on  animalfarm to public;
grant select, delete, insert, update on  birdfarm to public;
delete from animalfarm;
delete from birdfarm;
commit;
insert into animalfarm (code, description) values(111122, 'Horse');
insert into animalfarm (code, description) values(111133, 'Chicken');
insert into animalfarm (code, description) values(111144, 'Cow');
insert into animalfarm (code, description) values(111155, 'Pig');
insert into animalfarm (code, description) values(111166, 'Sheep');
insert into birdfarm (code, description) values(222, 'Pigeon');
insert into birdfarm (code, description) values(333, 'Sparrow');
insert into birdfarm (code, description) values(444, 'Chickadee');
insert into birdfarm (code, description) values(555, 'Blue Jay');
insert into birdfarm (code, description) values(666, 'Loon');
commit;
create or replace package birdfarm_Pkg is
function get_key_from_desc(bird_name_in in birdfarm.description%type) return number;
end birdfarm_Pkg;
create or replace package body birdfarm_Pkg is
function get_key_from_desc(bird_name_in in birdfarm.description%type) return number is
RETURN_VALUE birdfarm.code%TYPE;
BEGIN
       select code into RETURN_VALUE from birdfarm where description = bird_name_in;
       return RETURN_VALUE;
end get_key_from_desc;
END birdfarm_Pkg;
create or replace package animalfarm_Pkg is
--region Define Record Type for Strong Type REF CURSOR
TYPE AnimalFarmRecord is
  RECORD(
                  code animalfarm.code%type,
      description animalfarm.description%type,
                  birdfarm_code birdfarm.code%type
--endregion
TYPE animalfarmCur is REF CURSOR RETURN AnimalFarmRecord;
procedure get_code_two_ways(cur_OUT OUT animalfarmCur);
end animalfarm_Pkg;
create or replace package body animalfarm_Pkg is
procedure get_code_two_ways(cur_OUT OUT animalfarmCur) is
BEGIN
  open cur_OUT for
       select animalfarm.code,
              animalfarm.description,
              birdfarm_pkg.get_key_from_desc('Pigeon') birdfarm_code
       from animalfarm
       order by code;
end get_code_two_ways;
END animalfarm_Pkg;
create public synonym birdfarm_Pkg for db.birdfarm_Pkg;
grant execute on birdfarm_Pkg to public;
create public synonym animalfarm_Pkg for db.animalfarm_Pkg;
grant execute on animalfarm_Pkg to public;
See the sample code below:
             var conn = new OracleConnection(OraDB);
            conn.Open();
            conn.ClientId = "Sample";
            var command = new OracleCommand
                                  Connection = conn,
                                  CommandText = "DB.animalfarm_Pkg.get_code_two_ways",
                                  CommandType = CommandType.StoredProcedure
            command.Parameters.Add(new OracleParameter
                                   ParameterName = "cur_OUT",
                                   OracleDbType = OracleDbType.RefCursor,
                                   Direction = ParameterDirection.Output
            OracleDataReader dr = command.ExecuteReader(); // C#
            dr.Read();
            var code =dr.GetInt32(dr.GetOrdinal("Code")); //This is ok
            var description = dr.GetString(dr.GetOrdinal("Description"));
            var codeError = dr.GetInt32(dr.GetOrdinal("birdfarm_code"));//Throw invalid cast exception
                                                                        //because it is column function
            conn.Close();
            conn.Dispose();