MediumSQL challenge #158JOIN

Join Three Tables: Orders, Users and Payments

Return each order id with the customer's first name and the payment status.

The challenge runs on the SQLabHub practice database (SQLite) and uses the users, orders and payments tables. You can solve it in the browser, with nothing to install.

Solve This SQL Challenge

The task

Get order id, user name and payment status.

A correct answer returns 200 rows with 3 columns: id, first_name, status.

Tables used in this challenge

`users` 150 rows

id INTEGER (PK) · first_name TEXT · last_name TEXT · email TEXT · phone TEXT · city TEXT · country TEXT · created_at TEXT · status TEXT · is_premium INTEGER

First 3 rows of the users table
id	first_name	last_name	email	phone	city	country	created_at	status
1	Jennifer	Torres	jennifer.torres57@icloud.com	+1-263-376-2371	Houston	Canada	2024-04-13	active
2	Donna	Adams	donna.adams52@gmail.com	+1-753-780-6670	Fort Worth	Canada	2020-09-15	inactive
3	Kenneth	Young	kenneth.young94@proton.me	+1-440-743-9503	Austin	USA	2023-09-05	active

`orders` 200 rows

id INTEGER (PK) · user_id INTEGER · total REAL · discount REAL · item_count INTEGER · status TEXT · order_date TEXT · shipped_date TEXT · shipping_city TEXT · shipping_country TEXT

First 3 rows of the orders table
id	user_id	total	discount	item_count	status	order_date	shipped_date	shipping_city	shipping_country
1	43	2638.11	0.25	3	cancelled	2024-04-24	NULL	Los Angeles	USA
2	8	2947	0.19	5	delivered	2024-03-15	2023-04-09	Chicago	USA
3	136	683.24	0.08	2	delivered	2023-02-15	2023-07-10	Los Angeles	USA

`payments` 200 rows

id INTEGER (PK) · order_id INTEGER · user_id INTEGER · amount REAL · method TEXT · status TEXT · paid_at TEXT · transaction_id TEXT

First 3 rows of the payments table
id	order_id	user_id	amount	method	status	paid_at	transaction_id
1	46	105	921.62	Gift Card	success	2022-05-18	TXNHTN4GIK5L
2	157	37	1723.82	Bank Transfer	success	2024-11-11	TXNKJPIXJOFP
3	45	36	978.76	Bank Transfer	refunded	2023-10-24	TXNU2RW4MK1R

The first rows of each table are shown. See how all the tables relate on the database schema page.

Expected output

Expected output of the challenge
id	first_name	status
46	Susan	success
157	Anthony	success
45	Brian	refunded
104	Karen	failed
18	James	success

First 5 of 200 rows. This is the output of the model solution on the practice database. The task does not fix a sort order, so your rows may come back in a different order.

What you practise

Choosing exactly which columns a query returns
Combining rows from two tables on a matching key with an inner join

Hint and approach

Try the challenge first. Open these only when you need them.

Show the hint

JOIN 3 tables

Show the step-by-step approach

How the model solution is built, in the order the database evaluates it:

Read from the orders table.
Join users on orders.user_id = users.id.
Join payments on orders.id = payments.order_id.
Return only the columns orders.id, users.first_name and payments.status.

Model solution

Checking your session…

What to watch for

Each join adds one table and needs its own ON condition. Payments link to orders by order_id, and an order with several payment records would appear once per payment, so the row count follows the payments table.

INNER JOIN. An inner join drops rows that have no partner on the other side, and it repeats a row once for every match, which inflates SUM and COUNT.