MySQL - Error code 1140

Error Code: 1140. In aggregated query without GROUP BY, expression #1 of SELECT list contains nonaggregated column 'dbname.a.column_name'; this is incompatible with sql_mode=only_full_group_by

In order to resolve this issue, we have to turn off ONLY_FULL_GROUP_BY sql_mode.

1. Check sql_mode by issue this command:
   SELECT @@sql_mode;
2. You'll see the output like below:
   ONLY_FULL_GROUP_BY
3. Now turn off the ONLY_FULL_GROUP_BY by issuing this command:
   SET sql_mode = '';

Done!