Paging query through cursor

This method does not apply to MySQL, because MySQL cannot use cursors outside of stored procedures

– 开启一个事务
BEGIN;
– 定义游标
DECLARE t1_cur CURSOR FOR SELECT * FROM t1;
– 获取1000条记录
FETCH 1000 FROM t1_cur ;
– …
– 继续获取1000条记录
FETCH 1000 FROM t1_cur ;
–最后结束事务
COMMIT;