Database: book_1
Question: Show all book isbns which were ordered by both client Peter Doe and client James Smith.
SQL:
SELECT T2.isbn FROM Orders AS T1 JOIN Books_Order AS T2 ON T1.idOrder  =  T2.idOrder JOIN Client AS T3 ON T1.idClient  =  T3.idClient WHERE T3.name  =  "Peter Doe" INTERSECT SELECT T2.isbn FROM Orders AS T1 JOIN Books_Order AS T2 ON T1.idOrder  =  T2.idOrder JOIN Client AS T3 ON T1.idClient  =  T3.idClient WHERE T3.name  =  "James Smith"