What is the name of the first book written by J.K Rowling?
"J.K Rowling" is the author_name; first published book refers to book_id where Min(publication_date); name of the book refers to title
SELECT T1.title FROM book AS T1 INNER JOIN book_author AS T2 ON T1.book_id = T2.book_id INNER JOIN author AS T3 ON T3.author_id = T2.author_id WHERE T3.author_name = 'J.K. Rowling' ORDER BY T1.publication_date ASC LIMIT 1