SELECT name,sum(UNIX_TIMESTAMP(endtime)-UNIX_TIMESTAMP(starttime)) as sum1 FROM 表名 GROUP by name;
select examname,datediff(hh,starttime,endtime)from exam group by examname
我的意思是: 这个sum是有条件的,不是所有记录的总和,是某个时间段内的总合。 本来想写成: SELECT name,sum(UNIX_TIMESTAMP(endtime)-UNIX_TIMESTAMP(starttime)) as sum1 FROM 表名 GROUP by name where endtime<"2004-1-1 00:00:00" and starttime>"2004-1-2 00:12:00"可是这样写不行:(
where UNIX_TIMESTAMP(endtime)<UNIX_TIMESTAMP("2004-1-1 00:00:00") and UNIX_TIMESTAMP(starttime)>UNIX_TIMESTAMP("2004-1-2 00:12:00")
FROM 表名 GROUP by name;
本来想写成:
SELECT name,sum(UNIX_TIMESTAMP(endtime)-UNIX_TIMESTAMP(starttime)) as sum1
FROM 表名 GROUP by name
where endtime<"2004-1-1 00:00:00" and starttime>"2004-1-2 00:12:00"可是这样写不行:(