create or replace package PKG_TRANS_REL is

 -- Author : test
 -- Created : 
 -- Purpose : test

 -- Public type declarations
 PKG_NAME varchar2(20) := 'PKG_TRANS_REL';
 --存储过程，测试用
 procedure pro_GC_withdraw(in_merch_no   in varchar2,
              in_withdraw_amt in number,
              out_result   out number,
              out_errmsg   out varchar2);
end PKG_TRANS_REL;

  $this->_pdo = new PDO(PDO_DB_DNS, PDO_DB_USER, PDO_DB_PASSWORD);
  $call = "CALL PKG_TRANS_REL.pro_GC_withdraw(?,?,?,?)";

  try{
      $stmt = $this->_pdo->prepare($call);

      $stmt->bindParam(1, $merch_no);
      $stmt->bindParam(2, $amount, PDO::PARAM_INT);

      $stmt->bindParam(3, $result, PDO::PARAM_INT, 4);
      $stmt->bindParam(4, $error_msg, PDO::PARAM_STR, 64);

      $stmt->execute();

    }catch (PDOException $e)
    {
      $msg = 'SQL:'.$e->getMessage();
      $msg = iconv('GBK','UTF-8',$msg);
      user_dump('SQL:'.$msg);
      return false;
    }

    ...