mysql 触发器实现需求

drop trigger if exists tg_bb_insert;  
delimiter $$  
create trigger tg_bb_insert  
before insert on ceshi  
FOR EACH ROW  
BEGIN  
    declare ishave int;  
    select 1 into ishave from ceshiyong where id = New.id AND backupTs > CURDATE() AND backupTs < DATE_ADD(CURDATE(), INTERVAL 1 DAY) AND hour(now()) - hour(backupTs) < 2 order by backupTs desc limit 1; 
    if ishave is null then  
        insert into ceshiyong(id, count) values(NEW.id, New.count);  
    elseif ishave = 1 then  
        update ceshiyong set ceshiyong.count=New.count where id = New.id AND backupTs > CURDATE() AND backupTs < DATE_ADD(CURDATE(), INTERVAL 1 DAY) AND hour(now()) - hour(backupTs) < 2 order by backupTs desc limit 1; 
    else  
        -- 理论上不会调到 --
        insert into ceshiyong(id, count) values(NEW.id, New.count);  
    end if;  
END$$  
delimiter ;   

折腾一个需求：表1在做replace数据的时候，相同ID的数据，这次replace距离上次超过2小时就执行一下备份，懒的不愿写代码的关系，用触发器实现，这尼玛也是一个悲催的过程，这条语句折腾了我4个多小时。。纪念

mysql> desc ceshi;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | YES  |     | NULL    |       |
| count | int(11) | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
2 rows in set (0.01 sec)

mysql> desc ceshiyong;
+----------+-----------+------+-----+-------------------+-------+
| Field    | Type      | Null | Key | Default           | Extra |
+----------+-----------+------+-----+-------------------+-------+
| id       | int(11)   | YES  |     | NULL              |       |
| count    | int(11)   | YES  |     | NULL              |       |
| backupTs | timestamp | NO   |     | CURRENT_TIMESTAMP |       |
+----------+-----------+------+-----+-------------------+-------+
3 rows in set (0.01 sec)