select
   b.id as id, b.name as name, bas.authors as authors, b.classification as classification, bgs.genres as genres, b.published as published, bas.nationality as nationality
from
   books b
   left join (
      select
         ba.book_id, group_concat( concat_ws(' ', a.first_name, a.middle_name, a.last_name ) separator ', ' ) as authors, group_concat( c.nationality separator ', ' ) as nationality
      from
         book_authors ba
         join authors a on ba.author_id = a.id
         left join countries c on a.country_id = c.id
      group by
         ba.book_id) as bas on b.id = bas.book_id
   left join (
      select
         bg.book_id, group_concat(g.name separator ', ') as genres
      from
         book_genres bg
         join genres g on bg.genre_id = g.id
      group by
         bg.book_id) as bgs on b.id = bgs.book_id
order by
   1 asc
limit
   100 offset 0
;

select
   count(*) as count
from
   books b
;