Question

schema book: book_id, book_name, author_id. Author: author_id, first_name, last_name. DOB, social. i am trying to write a query that lists the first and last name of each author and counts how many books they wrote if they wrote more than one. but i am having issue . this is what i have so far, select book_name, count(b.book_name) as "number of books" from book b join author a on (b.author_id = a.author_id) group by b.book_name having count (a.author_id) >1;

Answer 1

Please find the SQL query below:

Query

select first_name, last_name, count(*) as NumberOfBooks from Author a join book b on a.author_id = b.author_id group by b.author_id having count(*) > 1;