MYSQL查询问题急求

[sddnnq]

我现在用的
SELECT sum( `in` ) `in` , sum( `out` ) `out` , sum( `c2` ) `c2` , `marker` FROM `clickip` WHERE `date` = '20120629'

为什么得不到这样结果
id marker in out c2
30 lun78 2 1 1
29 baba7 1 0 0

[ACMAIN_CHM]

SELECT sum( `in` ) `in` , sum( `out` ) `out` , sum( `c2` ) `c2` , `marker` FROM `clickip` WHERE `date` = '20120629' group by `marker`

[WWWWA]

SELECT `marker`,sum( `in` ) `in` , sum( `out` ) `out` , sum( `c2` ) `c2` FROM `clickip` WHERE `date` = '20120629' group by `marker`

[rucypli]

SELECT marker,max(id),sum( `in` ) `in` , sum( `out` ) `out` , sum( `c2` ) `c2` , `marker` FROM `clickip` WHERE `date` = '20120629'
group by marker

[Rotel-刘志东]

select id,sum('in') 'in',sum('out')'out',sum('c2')'c2',marker
from 'clickip'
where date='20120629'
group by id,marker
order by id desc;