Join Three Tables

One JOIN connects two tables. A query can have as many JOINs as it needs, one after another, and each one brings in a table with its own ON rule.

You need this for a table that links two others by their ids. In the shop, order_items has one row per product in an order: its order_id, its product_id and the quantity. It holds no date and no product name: the date is in orders, the name in products.

For example, a school's enrollments table links students to courses, and this query names both sides of each enrollment:

SELECT students.name, courses.title
FROM enrollments
JOIN students
ON enrollments.student_id = students.id
JOIN courses
ON enrollments.course_id = courses.id

Your query shows what each order contains: the order's id and date, the product's name and the quantity, one row per item. In your TypeScript code, each clause is one string in the query array, joined into one string with .join(" "). The check prints:

id | ordered | name | quantity
1 | 2026-03-02 | Mug | 2
1 | 2026-03-02 | Pen | 5
2 | 2026-03-15 | Lamp | 1
3 | 2026-04-05 | Notebook | 3
3 | 2026-04-05 | Pen | 10
4 | 2026-04-18 | Plant | 1
4 | 2026-04-18 | Mug | 1
5 | 2026-05-07 | Teapot | 2
5 | 2026-05-07 | Lamp | 1
6 | 2026-05-21 | Stapler | 1
7 | 2026-05-30 | Mug | 4
7 | 2026-05-30 | Notebook | 2
(12 rows)

Your task: select orders.id, orders.ordered, products.name and order_items.quantity from order_items, then join orders and products, each with its own ON.

Assignment
Follow the Coding Tutorial to start from order_items and join orders, then products, each JOIN with its own ON string.

Hint
Each ON compares a column of order_items with the id of the table being joined: order_id goes with the orders, product_id with the products.