PROCEDURE list_pk_columns(p_table IN VARCHAR2)
AS
  CURSOR c_list_pk_columns
  IS
    SELECT co.COLUMN_NAME
    FROM user_constraints pk,
      user_cons_columns co
    WHERE co.constraint_name = pk.constraint_name
    AND pk.table_name        = UPPER(p_table)
    AND pk.CONSTRAINT_TYPE      = 'P';
BEGIN
  DBMS_OUTPUT.put_line('Voici les colonnes qui composent la clé primaire :');
  FOR list_pk IN c_list_pk_columns
  LOOP
    DBMS_OUTPUT.put_line(list_pk.column_name);
  END LOOP;
END list_pk_columns;