-- Monthly sales trend SELECT YEAR(OrderDate) AS Year, MONTH(OrderDate) AS Month, SUM(od.UnitPrice * od.Quantity) AS Sales FROM Orders o JOIN [Order Details] od ON o.OrderID = od.OrderID GROUP BY YEAR(OrderDate), MONTH(OrderDate) ORDER BY Year, Month;
Introduction: Why Northwind Endures In the world of database training, documentation, and software testing, few artifacts have achieved the legendary status of the Northwind database . Since its creation by Microsoft in the late 1990s as a sample for Access, Northwind has been ported to virtually every database system—SQL Server, MySQL, PostgreSQL, SQLite, Oracle, and even NoSQL platforms. For over two decades, developers, data analysts, and students have used this fictitious trading company to learn SQL, test query performance, practice data modeling, and build demo applications. northwind database download
-- Most valuable customers by sales SELECT TOP 10 c.CompanyName, SUM(od.UnitPrice * od.Quantity) AS TotalSpent FROM Customers c JOIN Orders o ON c.CustomerID = o.CustomerID JOIN [Order Details] od ON o.OrderID = od.OrderID GROUP BY c.CompanyName ORDER BY TotalSpent DESC; -- Products never ordered SELECT ProductName FROM Products WHERE ProductID NOT IN (SELECT DISTINCT ProductID FROM [Order Details]); -- Monthly sales trend SELECT YEAR(OrderDate) AS Year,