用一条sql语句查询出8点钟的最大值，9点钟的最大值和10点钟的最大值，之前试过group by

select hour(etim),totalpower from table group by hour(etime) having totalpower=max（totalpower)大概这样应该可以

这样就行

SELECT MAX(totalpower),HOUR(Etime) FROM xx_table GROUP BY HOUR(Etime)