l'impression des variables pl/sql

J'ai le code suivant:

DECLARE
   v_hire_date DATE:='30-Oct-2000';
   v_six_years BOOLEAN;  
BEGIN
IF MONTHS_BETWEEN(SYSDATE,v_fecha_contrato)/12 > 6 THEN
      v_six_years:=TRUE;
ELSE
      v_six_years:=FALSE;
END IF;
DBMS_OUTPUT.PUT_LINE('flag '||v_six_years);
END;

Je veux imprimer la valeur de la variable v_six_years, mais j'obtiens l'erreur:

ORA-06550: line 10, column 24:
PLS-00306: wrong number or types of arguments in call to '||'
ORA-06550: line 10, column 3

Comment imprimer la valeur de la variable v_six_years?

OriginalL'auteur Layla | 2012-10-22