Mysql query for count

[Noorain]

sir

i want a query which count total student. here 6 record of student. here one student two times entry. my result is total student 5. i can't do this.

my table is:
id stu_name dob
1 Saima 2009-02-01
2 Tanvir 2009-02-11
3 Saima 2009-02-01
4 Rumman 2009-02-01
5 Saima 2009-02-26
6 Saima 2009-02-27

i use this query

select count(e.stu_name) as 'Total Number' from
stu_info e,stu_info d,stu_info c
where (e.stu_name <> d.stu_name
and e.dob = d.dob)

but it doesn't show proper result. please help me

Thanks

[mwasif]

You need a GROUP BY on name or DISTINCT

[CODE=mysql]select count(*) as 'Total Number' from
stu_info e,stu_info d,stu_info c
where (e.stu_name <> d.stu_name
and e.dob = d.dob)
GROUP BY e.stu_name[/CODE]

But in your case, you have different dob for students. This mean, some students with the same name may be different.

Use this code
[CODE=mysql]SELECT COUNT(*) as 'Total Number' FROM (
select count(DISTINCT e.stu_name) from
stu_info e,stu_info d,stu_info c
where (e.stu_name <> d.stu_name
and e.dob = d.dob)
) tmp
[/CODE]