How to select the first N rows of each group?

Question

I have two SQLite tables like this:

 AuthorId | AuthorName
----------------------
 1        | Alice
 2        | Bob
 3        | Carol
 ...      | ....


 Boo         


        

Answer 1

There is alternative variant:

SELECT * FROM (
    SELECT * FROM BOOK, AUTHOR
    WHERE BOOK.AUTHORID = AUTHOR.AUTHORID
) T1
WHERE T1.BOOKID IN (
    SELECT T2.BOOKID FROM BOOK T2
    WHERE T2.AUTHORID = T1.AUTHORID
    ORDER BY T2.BOOKTITLE
    LIMIT 2
)
ORDER BY T1.BOOKTITLE