How to select last record from each day with MySQL

Question

I know there are already some solutions to this question but they don't seem to be working for me.

I want to select the last record from each day, per user, on my database. I have a database that stores a user's location by country and date down to the second.

The select query I'm trying to run is:

SELECT MAX(date), id, country FROM dk_location_records WHERE userid = '10'
AND (date > '2012-04-06 00:00:00' AND date < '2012-05-08 23:59:59')
AND active = '1' GROUP BY DATE(date) ORDER BY date ASC

However, what this actually does is show me the last date from each day, but not the correctly corresponding id and country . It actually gets the first id and country , alongside the last date .

What am I doing wrong?

Help greatly appreciated!

Thanks,

Jack

Answer 1

Try this query to show last record from each day, per user, -

SELECT t1.* FROM dk_location_records t1
  JOIN (SELECT DATE(date) date_date, userid, MAX(date) max_date
        FROM dk_location_records
        GROUP BY date_date, userid
        ) t2
    ON t1.date = t2.max_date AND t1.userid = t2.userid;

...add your WHERE conditions if you need.

Answer 2

I think you should not group by DATE(date) . I think you should group by userid,country . Like this:

SELECT 
  MAX(date), userid, country 
FROM 
  dk_location_records 
WHERE 
  userid = '10'
  AND (date > '2012-04-06 00:00:00' AND date < '2012-05-08 23:59:59')
  AND active = '1' 
GROUP BY userid,country  
ORDER BY date ASC

Answer 3

您应该通过将ORDER BY更改为DESC而不是ASC来获得正确的结果