A Database Error Occurred

Error Number: 1055

Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'freegames4rest.games_category.category' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

SELECT `game_id`, `category` FROM (`games_category`) WHERE `game_id` IN ('murfy_maths', 'scepter_of_ra', 'ciao_bella', 'family_restaurant', 'fabulous_finds', 'agatha_christie_evil_under_the_sun', 'bubble_town', 'home_sweet_home_2', 'magic_match_adventures', 'go_go_gourmet', 'home_sweet_home', 'mahjongg_investigations_under_suspicion', 'turbo_pizza', 'great_escapes_solitaire', 'agatha_christie_death_on_the_nile', 'fairy_godmother_tycoon', 'dream_day_wedding', 'magic_match_the_genies_journey', 'saints_and_sinners_bingo', 'inspector_parker') GROUP BY `game_id`