using while
		JavaScript:
	
	DELIMITER //
CREATE PROCEDURE test4 ()
BEGIN
DECLARE paymentsSize INT DEFAULT 0;
DECLARE i INT DEFAULT 0;
select count(*) from payments into paymentsSize;
while i
using cursor[/SIZE]
[CODE=javascript]
--src - http://www.markomedia.com.au/mysql-cursors-in-stored-procedures/
DELIMITER // 
DROP PROCEDURE IF EXISTS sp_test //
CREATE PROCEDURE sp_test ()
BEGIN
	DECLARE done INT DEFAULT FALSE;
	DECLARE myid INT;
	DECLARE cur1 CURSOR FOR SELECT id from table1 WHERE firstname IS NULL;
	DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
	OPEN cur1;
	read_loop: LOOP
		IF done THEN
			LEAVE read_loop;
		END IF;
		FETCH cur1 INTO myid;
		UPDATE table1 SET firstname = (SELECT firstname from table2 WHERE id = myid)
		WHERE id = myid;
	END LOOP;
	close cur1;
END;