mySql中触发器的问题：当查询语句查询结果为空时出错。
mySql中触发器的问题：当查询语句查询结果为空时出错。错误信息为：
No   data   -   zero   rows   fetched   ,   selected,   or   proecssed.

有人遇到过吗？
我的触发器如下：
CREATE   TRIGGER   `temp_after_ins_tr`   AFTER   INSERT   ON   `temp`
    FOR   EACH   ROW
BEGIN
set   @countNumber   =   0;
set   @value1   =   '0 ';
set   @insertDaytime   =   ' ';
      Select   1,daytime,(NEW.value1)   into   @countNumber,@insertDaytime,@value1  
      From   temp
      where   substationid=NEW.substationid   and   switchid=NEW.switchid
      and   sanchu=0   and   daytime   <   NEW.daytime
      order   by   daytime   DESC
      limit   1;
     
      if   @countNumber=1   then
            insert   into   temp2(datetimes,substationid,switchid,value1)
            values
            (@insertDaytime,NEW.substationid,NEW.switchid,@value1);
      end   IF;
     
END;

结果在执行
  Select   1,daytime,(NEW.value1)   into   @countNumber,@insertDaytime,@value1  
      From   temp
      where   substationid=NEW.substationid   and   switchid=NEW.switchid
      and   sanchu=0   and   daytime   <   NEW.daytime
      order   by   daytime   DESC
      limit   1;
这个查询时，如果查询不到数据，则出错了。
请问我要怎么做？

------解决方案--------------------
try:

CREATE TRIGGER `temp_after_ins_tr` AFTER INSERT ON `temp`
FOR EACH ROW
BEGIN
set @countNumber = 0;
set @value1 = '0 ';
set @insertDaytime = ' ';
Select 1,daytime,(NEW.value1) into @countNumber,@insertDaytime,@value1
From temp
where substationid=NEW.substationid and switchid=NEW.switchid
and sanchu=0 and daytime < NEW.daytime
order by daytime DESC
limit 1;


insert into temp2(datetimes,substationid,switchid,value1)
select @insertDaytime,NEW.substationid,NEW.switchid,@value1
where ifnull(@countNumber,-1)=1;


END;