MySQL 5.7 ONLY_FULL_GROUP_BY

Abfrage für PhpMyAdmin:

SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY','') copy_me

Kompletter Code für eine Datei /etc/mysql/conf.d/myfile.cnf

[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"

Anschließend:

sudo systemctl restart mysql.service

In einer MySQL Shell kontrollieren:

select @@sql_mode

mysqli_query($connection, "SET SESSION sql_mode=''");