An Error Was Encountered

Error Number: 1055

Expression #4 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'carloscidrais_carloscidrais.i.foto_name' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

SELECT t.num as id, t.titulo, t.texto as texto, i.foto_name as video, i.tipo,, t.texto, g.foto_name AS img, g.titulo AS img_alt FROM site_content_txt AS t LEFT JOIN site_images AS i ON ( t.num = i.gal_id AND (i.tipo = 'mov' OR i.tipo = 'mp4') AND i.tipo IS NOT NULL ) LEFT JOIN site_images AS g ON ( t.num = g.gal_id AND g.tipo = 'image' ) WHERE active = 'yes' AND destaque = 'yes' AND t.tipo = 'calendar' GROUP BY t.num ORDER BY g.position ASC, RAND() LIMIT 10