Error related to only_full_group_by when executing a query in MySql

I have upgraded my system and have installed MySql 5.7.9 with php for a web application I am working on. I have a query that is dynamically created, and when run in older versions of MySQL it works fine. Since upgrading to 5.7 I get this error: > Expression #1 of SELECT list is not in GROUP BY clause and contains > non-aggregated column 'support_desk.mod_users_groups.group_id' which is > not functionally dependent on columns in GROUP BY clause; this is > incompatible with sql_mode=only_full_group_by Note the manual page for Mysql 5.7 on the topic of [Server SQL Modes][1]. This is the query that is giving me trouble: <!-- language: lang-sql --> SELECT mod_users_groups.group_id AS 'value', group_name AS 'text' FROM mod_users_groups LEFT JOIN mod_users_data ON mod_users_groups.group_id = mod_users_data.group_id WHERE mod_users_groups.active = 1 AND mod_users_groups.department_id = 1 AND mod_users_groups.manage_work_orders = 1 AND group_name != 'root' AND group_name != 'superuser' GROUP BY group_name HAVING COUNT(`user_id`) > 0 ORDER BY group_name I don't understand `only_full_group_by` enough to figure out what I need to do to fix the query. Can I just turn off the `only_full_group_by` option, or is there something else I need to do? [1]: http://dev.mysql.com/doc/refman/5.7/en/sql-mode.html