I发现它，谢谢:)

  SELECT  p.rollno，p.name， case  当 s.statuss = '  A' 然后 COUNT（p.rollno） else  '  0'  end   as 计算
来自出勤s 
正确  outer   join n>学生p 
  s.rollno = p.rollno 
和 s 。 date    '  10-09-2013' 和 '  13-10-2013' 
 group   by  p.rollno，p.regno，p.name，s.statuss 
 order   by  p .rollno; 

I have two tables,

student:
rollno | name
1      | Abc
2      | efg
3      | hij
4      | klm

attendance:
name | date       |statuss
Abc  | 10-10-2013 | A
efg  | 10-10-2013 | A
Abc  | 11-10-2013 | A
hij  | 25-10-2013 | A

my required output is:
some query with where condition as "where date between '10-09-2013' and '13-10-2013' "

rollno| name |count
1     | Abc  | 2
2     | efg  | 1
3     | hij  | 0
4     | klm  | 0

i tried using:

SELECT p.rollno,p.name,case when s.statuss='A' then COUNT(p.rollno) else '0' end as count from attendance s right outer join student p on s.rollno=p.rollno where s.date between '10-09-2013' and '13-10-2013' group by p.rollno,p.regno,p.name,s.statuss order by p.rollno

output is:
rollno| name |count
1     | Abc  | 2
2     | efg  | 1

i want the remaining values from the student table to also be appended,i tried many ways all are in vain,pls provide me a query which provides the output,
thanks in advance.

I found it,thank you :)

SELECT p.rollno,p.name,case when s.statuss='A' then COUNT(p.rollno) else '0' end as count
from    attendance s
        right outer join student p
            on s.rollno=p.rollno
            and s.date between '10-09-2013' and '13-10-2013'
group by p.rollno,p.regno,p.name,s.statuss
order by p.rollno;