[Resolved] complicated - subtracting dates

[Nate]

hi,

table raw_requests

site_id     session_id     request_id     logged_date_time
--------------------------------------------------------------------------
1             1                    1                    2004-01-01 12:00:31
1             1                    2                    2004-01-01 12:01:12
1             1                    3                    2004-01-01 12:01:49
1             2                    1                    2004-01-01 12:02:01
1             2                    2                    2004-01-01 12:02:34

I need to do a SELECT query that groups all rows by their session_id and in the process also subtracts the last date of a session with the first date of the same session... Is that possible?

So i need to return the following results based on the example table above:

site_id     session_id     total_time
---------------------------------------------
1             1                    00:01:18
1             2                    00:00:33

I'm able to return those results (but without the total_time) with the following query:

SELECT site_id, session_id
FROM raw_requests
GROUP BY session_id, site_id

[LordShryku]

Here's a stab in the dark....

  SELECT site_id, 
         session_id,
         (max(logged_date_time) - min(logged_date_time))
    FROM raw_requests
GROUP BY session_id, site_id

[Nate]

Thanks! That pretty much worked i just had to add timediff.

SELECT site_id, session_id,
TIMEDIFF(max(logged_date_time),
min(logged_date_time))
FROM raw_requests
GROUP BY session_id, site_id