Unique Categories
Get distinct product categories.
The challenge runs on the SQLabHub practice database (SQLite) and uses the products table. You can solve it in the browser, with nothing to install.
The task
Get distinct product categories.
A correct answer returns 10 rows with one column: category.
Tables used in this challenge
products 120 rows
id INTEGER (PK) · name TEXT · category TEXT · price REAL · cost REAL · stock INTEGER · sku TEXT · status TEXT · rating REAL · review_count INTEGER
| id | name | category | price | cost | stock | sku | status | rating | review_count |
|---|---|---|---|---|---|---|---|---|---|
The first rows of each table are shown. See how all the tables relate on the database schema page.
Expected output
| category |
|---|
The complete result: 10 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
- Removing duplicate rows with DISTINCT
Hint and approach
Try the challenge first. Open these only when you need them.
Show the hint
DISTINCT
Show the step-by-step approach
How the model solution is built, in the order the database evaluates it:
- Read from the
productstable. - Return only the column
category. DISTINCTremoves duplicate rows, so each value appears once.
Model solution
Checking your session…
What to watch for
- DISTINCT. DISTINCT works on the whole selected row. Adding one more column to the SELECT list can bring the duplicates back.
Related SQL challenges
- List Unique Cities with SELECT DISTINCTSimilar levelEasy
- Find Customers with at Least One Order Over 1,000HarderMedium
- Find Customers Who Ordered in 2024HarderMedium
- Find the Second Highest Order Total with LIMIT and OFFSETHarderMedium
Keep learning
- Lesson: SELECT DISTINCT
- All SQL practice challenges, by difficulty and topic
- SQL interview questions with answers
- SQL Playground: run any query on the same database