Execption "too many rows"

DROP TABLE aaa;

CREATE TABLE aaa (
   b NUMBER
);

INSERT INTO aaa
VALUES (1);

DROP PROCEDURE ppp;

CREATE OR REPLACE PROCEDURE ppp
IS
BEGIN
   DECLARE
      dummy   NUMBER;
   BEGIN
      SELECT b
      INTO dummy
      FROM aaa;

      DBMS_OUTPUT.put_line ('value is ' || dummy);
   END;
END;
/

exec ppp;

Procedure created.
PL/SQL procedure successfully completed.
1 row created.
value is 1

INSERT INTO aaa
VALUES (2);

exec ppp;

1 row created.
BEGIN ppp; END;
Error at line 4
ORA-01422: l'extraction exacte ramène plus que le nombre de lignes demandé
ORA-06512: à "PPP", ligne 7
ORA-06512: à ligne 1

CREATE OR REPLACE PROCEDURE ppp
IS
BEGIN
   DECLARE
      dummy   NUMBER;
   BEGIN
      SELECT b
      INTO dummy
      FROM aaa;

      DBMS_OUTPUT.put_line ('value is ' || dummy);
   EXCEPTION
      WHEN TOO_MANY_ROWS
      THEN
         DBMS_OUTPUT.put_line ('catched error :-)');
   END;
END;
/

exec ppp;

catched error :-)