CREATE PROCEDURE CSNTAuthUserPap
@username varchar(64), @pass varchar(255)
AS
SET NOCOUNT ON
IF EXISTS(SELECT userid FROM reader WHERE userid = @username AND passwd = @pass)
SELECT 0,'1','odbc','No Error' FROM reader WHERE userid = @username
ELSE
SELECT 3,0,'odbc','ODBC Authen Error'
GO

try:

create or replace procedure CSNTAuthUserPap
(
username          in varchar2(64),
pass                 in varchar2(255)
)
is
declare x integer;
begin
select count(userid) into x from reader where userid = username and passwd = pass)
if x>0 then
        select 0,'1','odbc','No Error' from reader where userid = username;
else
        select 3,'0','odbc','ODBC Authen Error';

end;