Group mysql query by 15 min intervals
SELECT FLOOR(UNIX_TIMESTAMP(timestamp)/(15 * 60)) AS timekey
FROM table
GROUP BY timekey;
Try this , grouping of records of 15 minutes interval, you can change 15*60 to the interval in seconds you need
SELECT sec_to_time(time_to_sec(datefield)- time_to_sec(datefield)%(15*60)) as intervals from tablename
group by intervals