p.ProductName, s.CompanyName, p.UnitPrice
FROM Products p, Suppliers s
where p.SupplierID = s.SupplierID
2、
SELECT CategoryID, avg(UnitPrice) FROM Products group by CategoryID
3、
SELECT o.OrderID, c.CompanyName, e.LastName, e.FirstName, o.OrderDate
FROM Orders o, Customers c, Employees e
where o.CustomerID = c.CustomerID
and e.EmployeeID = o.EmployeeID
ORDER BY o.OrderDate
use Northwind
GO
select * from Orders