структуру table1 покажите - интересует как объявлено field2. Если поле символьное, то должно работать.

Ещё как работает. IDS 7.31. Да и позже должно работать. Заполни анкету - версия сервера, что за клиент, осы клиента, сервера...

1. Полная документация доступна на сервере IBM совершенно бесплатно.
2. Количество записей (dbinfo('sqlca.sqlerrd2')):
Iformix SQL guideThe 'sqlca.sqlerrd2' option returns a single integer that provides the number
of rows that SELECT, INSERT, DELETE, UPDATE, and EXECUTE PROCEDURE
statements processed. To ensure valid results, use this option after SELECT
and EXECUTE PROCEDURE statements have completed executing. In
addition, to ensure valid results when you use this option within cursors,
make sure that all rows are fetched before the cursors are closed.
The following example shows a stored procedure that uses the
'sqlca.sqlerrd2' option to determine the number of rows that are deleted from
a table:
CREATE PROCEDURE del_rows (pnumb int)
RETURNING int;
DEFINE nrows int;
DELETE FROM fst_tab WHERE part_num=pnumb;
LET nrows = DBINFO('sqlca.sqlerrd2');
RETURN nrows;
END PROCEDURE
3. While (ещё есть for и foreach):
Informix SQL guide Example of WHILE Loops in a Stored Procedure
The following example illustrates the use of WHILE loops in a stored
procedure. The first WHILE loop executes a DELETE statement. The second
WHILE loop executes an INSERT statement and increments the value of a
procedure variable.
CREATE PROCEDURE simp_while()
DEFINE i INT;
WHILE EXISTS (SELECT fname FROM customer
WHERE customer_num > 400)
DELETE FROM customer WHERE id_2 = 2;
END WHILE;
LET i = 1;
WHILE i < 10
INSERT INTO tab_2 VALUES (i);
LET i = i + 1;
END WHILE;
END PROCEDURE