Угадать случайное число Oracle

-- CREATE TABLE DEVICES ( DEVICE   VARCHAR2(100),  MESSAGE  VARCHAR2(100),  RESULT   VARCHAR2(100));
-- insert into devices values ('STD_IN', 'hidding number', null);
-- insert into devices values ('STD_OUT', 'message', null);
 
--------1)
CREATE OR REPLACE FUNCTION read_from_stdin
   RETURN NUMBER
IS
   a   NUMBER;
BEGIN
   SELECT ROUND (DBMS_RANDOM.VALUE (1, 10)) rnum INTO a FROM DUAL;
   RETURN a;
END;
/
 
 
--------2)
CREATE OR REPLACE FUNCTION get_user_input
   RETURN VARCHAR2
    IS v_result VARCHAR2(100);
BEGIN 
v_result:=read_from_stdin;
SELECT 
MESSAGE
INTO v_result
  FROM devices
 WHERE     device = 'STD_IN'
       AND MESSAGE = 'hidden number'
       AND MESSAGE IS NOT NULL;
EXCEPTION
WHEN NO_DATA_FOUND
 THEN
raise_application_error(-20101, 'Value is missing');
END;
 
---------3)
CREATE OR REPLACE FUNCTION read_hidden_number
   RETURN NUMBER
IS
   a   NUMBER;
BEGIN
   SELECT ROUND (DBMS_RANDOM.VALUE (1, 100)) rnum INTO a FROM DUAL;
 
   RETURN a;
END;
/
 
--------4)
CREATE OR REPLACE PROCEDURE SCOTT.write_into_stdin
(      p_device  VARCHAR2
    , p_message  VARCHAR2
    , p_result VARCHAR2
    )
 IS
 PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
INSERT INTO devices (device
    , message
    , result
)
VALUES ( p_device
    , p_message
    , p_result
);
COMMIT;
END;
/
---------5)
CREATE OR REPLACE PROCEDURE SCOTT.find_hidden_number
IS
   v_hidden_number   NUMBER;
   v_user_input      NUMBER;
    i PLS_INTEGER := 0;
   v_error_flag NUMBER;
BEGIN
   v_hidden_number := read_hidden_number;
    v_user_input := get_user_input;
   FOR i IN 1..7
   LOOP
           IF v_user_input < v_hidden_number
      THEN
         DBMS_OUTPUT.put_line ('number higher');
      ELSIF v_user_input > v_hidden_number
      THEN
         DBMS_OUTPUT.put_line ('number below');
      ELSIF v_user_input = v_hidden_number
      THEN
         DBMS_OUTPUT.put_line ('the number is correct');
         ELSE v_error_flag :=1;
         EXIT;
      END IF;
   END LOOP;
END find_hidden_number;
/

CREATE OR REPLACE PROCEDURE prc_write_into_stdin (p_name     VARCHAR2,
                                                  p_value    VARCHAR2)
IS
   PRAGMA AUTONOMOUS_TRANSACTION;
   v_value   PLS_INTEGER;
BEGIN
   UPDATE t_io_device
      SET ch_value = p_value
    WHERE ch_type = 'stdin' AND ch_name = p_name;
 
   COMMIT;
END prc_write_into_stdin;

CREATE OR REPLACE FUNCTION fnc_read_from_stdin (p_name VARCHAR2)
   RETURN PLS_INTEGER
IS
   PRAGMA AUTONOMOUS_TRANSACTION;
   v_value   PLS_INTEGER;
BEGIN
   WHILE TRUE
   LOOP
      BEGIN
         SELECT ch_value
           INTO v_value
           FROM t_io_device
          WHERE     ch_type = 'stdin'
                AND ch_name = p_name
                AND ch_value IS NOT NULL;
         UPDATE t_io_device
            SET ch_value = NULL
          WHERE ch_type = 'stdin' AND ch_name = p_name;
         COMMIT;
         EXIT;
      EXCEPTION
         WHEN NO_DATA_FOUND
         THEN
            CONTINUE;
      END;
   END LOOP;
 
   RETURN TO_NUMBER (v_value);
END fnc_read_from_stdin;