EXECUTE IBEBLOCK
AS
declare variable ID integer;
BEGIN
  FOR
    WITH RECURSIVE T (ID)
    AS (SELECT
          1 AS ID
        FROM
          RDB$DATABASE R1
        WHERE
          1 = 1
        UNION ALL
        SELECT
          2 as ID
        FROM
          RDB$DATABASE R2
        JOIN T on T.ID = R2.RDB$RELATION_ID)
  SELECT
    ID
  FROM
    T
  INTO
    :ID
DO
BEGIN
END  
END