To keep your current mysql settings and disable ONLY_FULL_GROUP_BY
I suggest to visit your phpmyadmin or whatever client you are using and type:
SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY','') copy_me
next copy result to your my.ini
file.
mint: sudo nano /etc/mysql/my.cnf
ubuntu 16 and up: sudo nano /etc/mysql/my.cnf
ubuntu 14-16: /etc/mysql/mysql.conf.d/mysqld.cnf
copy_me
result can contain a long text which might be trimmed by default. Make sure you copy whole text!old answer:
If you want to disable permanently error "Expression #N of SELECT list is not in GROUP BY clause and contains nonaggregated column 'db.table.COL' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by" do those steps:
sudo nano /etc/mysql/my.cnf
Add this to the end of the file
[mysqld]
sql_mode = "STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
sudo service mysql restart
to restart MySQL
This will disable ONLY_FULL_GROUP_BY
for ALL users