Grouping data by time period

Hi everyone,

I'm now on a TSQL problem and hope somebody here can help me.
I have a log data for a website that logs IP addresses and date/time of the access, and I shall group IP values by time period, beginning from the 1st access, at each 30 minutes.

Does anyone here can help me with this issue? Any tips will be very appreciated.

TIA

MarceloHere is a generic code that you should get you started.
declare @.interval int
set @.interval=30
select dateadd(minute,floor(datediff(minute,0,OrderDate)/@.interval)*@.interval,0) [dt],
count(*) [cnt]
from Northwind..Orders
group by dateadd(minute,floor(datediff(minute,0,OrderDate)/@.interval)*@.interval,0)
order by 1|||Thanks a lot, worked like a charm. Only thing I need to figure out now is how to count 30 minutes since first access from an IP address, but your code will help me a lot.

Regards,

group by help?

I am trying to get the last occurance of a display name in a login user log database. Basically I have a table that looks like this:

id user fname lname
-----------
1 jdoe Jane Doe
2 jdoe John Doe
3 jdoe Fred Flinstone

I run the MySQL query: SELECT name, max(id) as max_id, user FROM `logins` GROUP BY user

I get back:
id user fname lname
-----------
3 jdoe Jane Doe

I actually want:
id user fname lname
-----------
3 jdoe Fred Flinstone

Any that can help it would be greatly Appreciated!!by "last" occurrence you mean the one with the largest id?
select id
, user
, fname
, lname
from logins as ZZ
where id
= ( select max(id)
from logins
where user = ZZ.user )|||I tried this result and am still having difficulties? Do you know if this works with all versions of MySQL? I get the following error from phpmyadmin:

You have an error in your SQL syntax near 'select max(id) from logins where user=ZZ.user

Any other thoughts?|||good guess -- subqueries are not supported prior to version 4.1

how come it took you two and a half weeks to try my solution?|||If a correlated subquery is not supported, let's hope a join (and a group by) is?
Could you try this one: select a.id, a.user, a.fname, a.lname
from logins as a, logins as b
where a.user = b.user
and a.id <= b.id
group by a.id, a.user, a.fname, a.lname
having count(*) = 1