Question

I have a query:

SELECT MIN(stat_md5) AS stat_md5 
FROM 
     (select * from ( mem_stat NATURAL LEFT OUTER JOIN host ))
GROUP BY stat_md5;

This query is running fine in SQLite version 3.4.2, but when I upgraded to version 3.7.11, it is giving following error:

SQL error: aggregate functions are not allowed in the GROUP BY clause

If I remove MIN() or GROUP BY or AS from the query, then its working fine in version 3.7.11.

It means following variants of query are working fine:

SELECT MIN(stat_md5) AS stat_md5 
FROM 
     (select * from ( mem_stat NATURAL LEFT OUTER JOIN host ))


SELECT MIN(stat_md5) 
FROM 
     (select * from ( mem_stat NATURAL LEFT OUTER JOIN host ))
GROUP BY stat_md5;


SELECT stat_md5 
FROM 
     (select * from ( mem_stat NATURAL LEFT OUTER JOIN host ))
GROUP BY stat_md5;

Can someone please explain why is it giving error in version 3.7.11 and workaround for it.

UPDTATE:

This is the original query.

SELECT 
      stat_day, obs_day, stat_week, obs_week, 
      NULL AS stat_cputotal, stat_memfree, stat_md5,
      stat_month, obs_month, stat_type, stat_memused, stat_10min, obs_10min, 
      NULL AS stat_cpusystem, stat_epoch, obs_epoch, stat_30day, obs_30day, 
      stat_idx, obs_idx, NULL AS stat_cpuidle, stat_memtotal, stat_qtr, obs_qtr,
      NULL AS stat_cpuuser, stat_hour, obs_hour, obs_10min, stat_10min, 
      obs_30day,stat_30day, obs_day, stat_day, obs_epoch, stat_epoch, obs_hour,
      stat_hour, obs_idx, stat_idx, obs_month, stat_month, obs_qtr, stat_qtr, 
      obs_week, stat_week, serial_num, NULL AS dputil_cpuid, NULL AS wms_pk 
      FROM (
       (
       SELECT stat_qtr, obs_qtr, stat_qtr AS cus_qtr, stat_qtr AS crash_qtr, 
              stat_qtr AS evt_qtr, stat_30day, obs_30day, stat_30day AS cus_30day, 
              stat_30day AS crash_30day, stat_30day AS evt_30day, stat_month, 
              obs_month, stat_month AS cus_month, stat_month AS crash_month, 
              stat_month AS evt_month, stat_week, obs_week, stat_week AS cus_week, 
              stat_week AS crash_week, stat_week AS evt_week, stat_day, obs_day, 
              stat_day AS cus_day, stat_day AS crash_day, stat_day AS evt_day, 
              stat_hour, obs_hour, stat_hour AS cus_hour, stat_hour AS crash_hour, 
              stat_hour AS evt_hour, stat_10min, obs_10min, stat_10min AS cus_10min, 
              stat_10min AS crash_10min, stat_10min AS evt_10min, stat_epoch, 
              obs_epoch, stat_epoch AS cus_epoch, stat_epoch AS crash_epoch, 
              stat_epoch AS evt_epoch, stat_idx, obs_idx, stat_idx AS cus_idx, 
              stat_idx AS crash_idx, stat_idx AS evt_idx, obs_10min, obs_30day, 
              obs_day, obs_epoch, obs_hour, obs_idx, obs_month, obs_qtr, obs_week, 
              serial_num, stat_md5, MIN(stat_memfree) AS stat_memfree, MIN(stat_md5) 
              AS stat_md5, MIN(stat_type) AS stat_type, MIN(stat_memused) AS 
              stat_memused, MIN(stat_memtotal) AS stat_memtotal 
              FROM 
                   (select * from ( mem_stat NATURAL LEFT OUTER JOIN host )) 
                    GROUP BY 
                            stat_qtr, stat_30day, stat_month, stat_week, 
                            stat_day, stat_hour, stat_10min, stat_epoch, 
                            stat_idx, obs_10min,obs_30day, obs_day, obs_epoch, 
                            obs_hour, obs_idx, obs_month, obs_qtr, obs_week, 
                            serial_num, stat_md5
                   ))

Answer 1

, stat_md5, MIN(stat_memfree) AS stat_memfree, MIN(stat_md5) AS stat_md5,

stat_md5 is twice on the SELECT list: once alone and once as the alias of a MIN(). 3.4.2 must have used the first one and 3.7.11 must be using the second.

Grouping by an aggregated field makes no sense, so the error is right.

Just change the alias of the second time to something like AS min_stat_md5 and it will work fine. Having two fields with the same name on a SELECT is bad idea in any case.