Orders in Java

The shop's database holds more than products. The table orders has one row per order: its id, the customer_id of the customer who placed it, the date it was placed (ordered) and its status. The customer's name is not in that row: it lives in another table, customers.

A JOIN reads two tables in one query. Its ON condition says which rows belong together, and table.column says which table a column comes from. Here is the idea on two other tables, books and their authors, with the query built in pieces:

String sql = "";
sql += "SELECT books.title, authors.name AS author ";
sql += "FROM books ";
sql += "JOIN authors ON authors.id = books.author_id ";

Each book is paired with the one author whose id is the book's author_id. AS author renames the column in the result, so each row's map has the key "author". += adds each piece to the end of the String exactly as written, with nothing between, so end each piece with a space.

Your method must give these answers:

GET /orders/1   →  200  {"id": 1, "ordered": "2026-03-02", "status": "paid", "customer": "Ana Pop"}
GET /orders/4   →  200  {"id": 4, "ordered": "2026-04-18", "status": "shipped", "customer": "Chloe Ng"}
GET /orders/6   →  200  {"id": 6, "ordered": "2026-05-21", "status": "cancelled", "customer": "Ben Ortiz"}
GET /orders/99  →  404  {"error": "Order not found"}

Your task: finish GET /orders/{orderId}. It reads the order and its customer's name with one JOIN query and answers them as JSON, or 404 when no order has that id.

Assignment
Follow the Coding Tutorial to write the method getOrder and its JOIN query.

Hint
Both tables have a column id, so write orders.id or customers.id, never just id. db.queryForList gives an empty list when no order has that id, as in getProduct.