Database: book_1
Question: Show the client name who has the most total amount of books ordered.
SQL:
SELECT T2.name FROM Orders AS T1 JOIN Client AS T2 ON T1.idClient  =  T2.idClient JOIN Books_Order AS T3 ON T3.idOrder  =  T1.idOrder GROUP BY T1.idClient ORDER BY sum(T3.amount) DESC LIMIT 1