[chaley]

BTW, the reason your SQL doesn't work is that some of the subqueries return multiple rows. You only see the first one. To see all of them you need to use group_concat(), like this:

SELECT
    id,
    author_sort,
    title,
    (SELECT name FROM publishers WHERE publishers.id IN (SELECT publisher from books_publishers_link WHERE book=books.id)) publisher,
    (SELECT group_concat(format) FROM data WHERE data.book=books.id) formats,
    path,
    (SELECT group_concat(name) FROM tags WHERE tags.id IN (SELECT tag from books_tags_link WHERE book=books.id)) tags
FROM books