Web App cannot query DB

Hello,

I recently migrated my DB to the DO VPS, all went well, I’ve updated my webapp to query the localhost DB instead of the old one but I get error like this: SQLSTATE[42000]: Syntax error or access violation: 1055 Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column ‘myDB.p0_.id’ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by"

My app is developed on the Symfony 3 framework, with Doctrine ORM.

Please let me know what I can do to fix that error.

Thanks, Roland