php - Mysql Group By Last Slno (最新版)

Question

我正在尝试通过最后一个 Slno 获得价值组

这是我的桌子

slno  title       date_added  comp_name  cat
----  ----------  ----------  ---------  ----
   1  title1.0    1jan2012    AAA        cat1
   2  title 2.5   3jan2012    AAA        cat1
   3  title 30.2  5jan2012    AAA        cat1
   4  title 41.2  9jan2012    AAA        cat1

这是我的查询

SELECT slno,title,date_added
from files where cat = :cat 
GROUP by comp_name
Order By comp_name DESC limit 12

输出是

title1.0**1(slno)

我想得到输出

title 41.2**4(slno)

请帮忙

编辑...

好的，让我们按 comp_name 和 last slno 分组...

Answer 1

就像是：

SELECT slno,title,date_added
from files,
  (select max(slno) as mslno,comp_name from files where cat=:cat group by comp_name) t1
 where cat = :cat 
   and slno=mslno
   and files.comp_name=t1.comp_name
Order By files.comp_name DESC limit 12