sql关于雷同父ID最多取3记录

sql关于相同父ID最多取3记录
表 imginfo
id    fid    miaoshu
1      3     aaaaaaa
2      3     sssssss
3      3     fffff
4      4     uuuuuuuu
5      5     gfgfgfgfgf
6      5     ddfdfdfd
7      9     fdffdfd
8      9     dfdfdfd
9      9     dfdfdf
10     9     popopop
11     3     tgtrtyrtyry
12     5      fdsjfdfdl

SELECT * FROM `imginfo` WHERE fid in(3,5,9) ORDER BY `id` DESC 
上面这条语句fid 3,5,9全部内容都获取了。

现在我只想每条相同fid最多获取3条，排序不变，sql语句怎么写？ 
请大家指教请高人指教。不胜感激！ 

------解决方案--------------------

select a.* from imginfo a where 3 > (select count(*) from imginfo where fid = a.fid and id > a.id and fid in(3,5,9)) and fid in(3,5,9) order by a.fid,a.id