Question:groups orders by CUSTOMER.LastName, CUSTOMER.FirstName
and INVOICE.InvoiceNumber in that order, and (3) sums and averages.
My query:
CREATE VIEW CustomerOrderHistoryView AS
SELECT INVOICENUMBER,FIRSTNAME,LASTNAME,PHONE,DATEIN,DATEOUT,SUBTOTAL,
EXTENDEDPRICE FROM CUSTOMERORDERSUMMARYVIEW
GROUP BY LASTNAME,FIRSTNAME,INVOICENUMBER;
But i get an error. NOT A GROUP BY expression what should i change in order to follow the requirement of my questions? and what the quesiton mean by (3) sums and averages? suspect question unclear