Remove ONLY_FULL_GROUP_BY in my.cnf file
First you need to find my.cnf file location and then edit it. Enter following command in your ssh as root user.
mysql --help | grep my.cnf
Now you will get output something like this.
order of preference, my.cnf, $MYSQL_TCP_PORT,
/etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf
Mostly main MySQL configuration file my.cnf location is "/etc/my.cnf"
now open the file:
vim /etc/my.cnf
You will see some lines are as follow.
[mysqld]
performance-schema=0
You just need to add one line between them, then new text will be.
[mysqld]
sql_mode =
performance-schema=0
Just save the file and restart your MySQL services.
mysql service restart
That's all.