I recently upgraded to MySQL v5.7 from v5.6 on RDS.
Now I sometimes get the error:
Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'USER.t.training_team_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
I checked my config with SELECT @@GLOBAL.sql_mode and only get:
NO_ENGINE_SUBSTITUTION
However this still happens.
The weird part is, that it only happens sometimes. I cannot force it to happen and I can't seem to disable the only_full_group_by option.
How do I change this?