The REST web service contains a mapping that reads a Customers table to retrieve the customer name. The mapping contains a Lookup transformation. The Lookup transformation retrieves all the orders for each customer from an Orders table. The mapping contains a REST Output transformation that returns a hierarchical JSON file. The JSON file structure has customer number and customer name in a parent group. The JSON file contains a child group for the orders within customer. The group contains multiple occurring orders. Each order has an order number, price, and order date.