Re: Query in mysql 5.5 fails in mysql server version 5.7.16

[Peter Brawley]

Give the error report another reading, "as detailed as possible": a sql_mode setting of only_full_group_by prohibits non-aggregated columns that aren't functionally dependent on Group By clause columns.

Consider also giving https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html an "as detailed as possible" reading. Non-aggregated non-Group_by columns return arbitrary values, so your 5.5 queries were probably returning misleading results.