我试图实现一个存储过程来创建用户余额的快照，但我总是在第5行中得到一个错误，即语法错误，并且我还没有找到该语法错误的答案：

DROP PROCEDURE IF EXISTS createSnapshot;

DELIMITER //

CREATE PROCEDURE createSnapshot()
BEGIN
INSERT INTO balance_history (uid,coin_id,balance) SELECT uid,coin_id,amount FROM balance;

DECLARE done INT DEFAULT FALSE;

DECLARE cursor1 CURSOR FOR SELECT primary_key,timestamp FROM balance_history WHERE timestamp < DATE_SUB(NOW(), INTERVAL 7 DAY); 

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

DECLARE id INT;

DECLARE time1 TIMESTAMP;

OPEN cursor1;

read_loop: LOOP;
    IF done THEN
      LEAVE read_loop;
    END IF

    FETCH cursor1 INTO id,time1;
END LOOP

CLOSE cursor1;
END//

分隔符；