Question

This is the DB Schema:

Books (bookid, title, author, year)
Customers (customerid, name, email)
Purchases (customerid, bookid, year)
Reviews (customerid, bookid, rating)
Pricing (bookid, format, price)

How do I find customers (show their names and email addresses) who purchased more than one book in year 2003?

Answer 1

pretty much exactly like your english language question phrased it… just translated into SQL …

Select * From Customers C
Where (Select Count(*) From Purchases
       Where customerid = C.customerid
           And Year = 2003) > 1