MySQL Query does not use index in table join

Question

I am trying to list all the book_sales information for a particular book author. So I have a query and it\'s not using Index to lookup records.

The followin

Answer 1

Try this

SELECT sale_amount, price
FROM book_sales,books
LEFT JOIN books ON(book_sales.book_id = books.book_id)
WHERE books.author_id =1