MySql 8.0 Fix ONLY_FULL_GROUP_BY issue
Solution 1: Remove ONLY_FULL_GROUP_BY from mysql console
SET GLOBAL sql_mode=(SELECT REPLACE(@@sql_mode,'ONLY_FULL_GROUP_BY',''));
you can read more here
Solution 2: Remove ONLY_FULL_GROUP_BY from phpmyadmin
- Open phpmyadmin & select localhost
- Click on menu Variables & scroll down for sql mode
- Click on edit button to change the values & remove ONLY_FULL_GROUP_BY & click on save.

ref: https://stackoverflow.com/questions/23921117/disable-only-full-group-by