INSERT INTO
ITEMSOPERATION (ID_IORD, OPERVALUE)
VALUES
(1453, 0), (1456, 0)

s_tmp := copy(s_str, 1, pos(',', s_str) - 1)

EXECUTE block (sIORD VARCHAR(255) = :sIORD)
AS
DECLARE variable s_tmp1 VARCHAR(255);
DECLARE variable s_tmp2 VARCHAR(255);
BEGIN
  s_tmp1 = :sIORD;
  while (s_tmp1 <> '') do
    begin
      if (POSITION (',' in s_tmp1) = 0) then
        begin
          s_tmp2 = :s_tmp1;
          s_tmp1 = '';
        end
      else
        s_tmp2 = SUBSTRING(s_tmp1 from 1 for POSITION (',' in s_tmp1) - 1);

      insert into ITEMSOPERATION (ID_IORD, OPERVALUE) values (:s_tmp2, 0);

      s_tmp1 = SUBSTRING(s_tmp1 from POSITION (',' in s_tmp1) + 1 for CHAR_LENGTH(s_tmp1));
    end
END