使用oracle写if判断

DECLARE
  L_X INT;
BEGIN
  SELECT COUNT(*) INTO L_X FROM SYSTEMROLEFUNCTION WHERE ROLEID = '1';
  IF L_X > 0 THEN
    INSERT INTO SYSTEMROLEFUNCTION
      (FUNCTIONID, ROLEID)
    VALUES
      ('123', '1');
  END IF;
  COMMIT;
END;