看来是个考勤的,抓那个最晚的,还有警告标志! 日! 小写一把哈: ---------- select a.groupid, b.groupname, a.name, a.alarm from (select groupid, max(time) time from a where alarm = 1 group by groupid) t1, a, b where a.groupid = t1.groupid and b.groupid = t1.groupid and a.time = t1.time and a.alarm = 1 ----------
操,我写的也有点问题,改一下啊 select a.groupid, b.groupname, a.name, a.alarm from (select groupid, max(time) time from a where alarm = 1 group by groupid) t1, a, b where a.groupid = t1.groupid and b.groupid = a.groupid and a.time = t1.time and a.alarm = 1
select a1.groupid,b1.groupName,a1.name,a1.alarm from table_a a1,table_b b1 (select groupid,max(time) as time from table_a group by groupid) max1 where a1.groupid = max1.groupid and a1.time = max1.time and a1.alarm = 1 and b1.groupid = a1.groupid
select b.Groupid,b.GroupName,min(a.name),min(a.alarm) from a,b where a.Groupid=b.Groupid group by b.Groupid,b.GroupName
小写一把哈:
----------
select a.groupid, b.groupname, a.name, a.alarm
from (select groupid, max(time) time from a where alarm = 1 group by groupid) t1, a, b
where a.groupid = t1.groupid and b.groupid = t1.groupid and a.time = t1.time and a.alarm = 1
----------
要是有好几个人,都来的最晚,时间也一样,但是有的有警告标志,有的没有警告标志怎么办?
select a.groupid, b.groupname, a.name, a.alarm
from (select groupid, max(time) time from a where alarm = 1 group by groupid) t1, a, b
where a.groupid = t1.groupid and b.groupid = a.groupid and a.time = t1.time and a.alarm = 1
select a1.groupid,b1.groupName,a1.name,a1.alarm from table_a a1,table_b b1
(select groupid,max(time) as time from table_a group by groupid) max1
where a1.groupid = max1.groupid
and a1.time = max1.time
and a1.alarm = 1
and b1.groupid = a1.groupid
from a,b
where a.Groupid=b.Groupid
group by b.Groupid,b.GroupName