Users by Device Type
How many users registered on each type of device?
- Aggregation
- Sorting
Challenge brief
Understand the request
Device Strategy needs the registered-user device mix for product planning.
Return device_type, user_count in the declared deterministic order.
Return
- device_type
- user_count
Constraints
- Return one row per device type
- Order by user count descending, then device type
Data you will use
Review the relevant tables before deciding how to join, filter, or aggregate them.
users
device_typeVARCHAR(20)
Hints, when you need them
Open one clue at a time so you still do the reasoning.
Hint 1
Device type is stored on each registered user.
Hint 2
Count users within each device group.
Hint 3
Use device type to stabilize equal group sizes.
Verified SQL answer
Attempt the problem first, then compare structure and reasoning—not just syntax.
Reveal solution and explanation
SELECT device_type, COUNT(*) AS user_count FROM users GROUP BY device_type ORDER BY user_count DESC, device_typeWhy this works
23 users split across 3 device types: 12 mobile (52%), 7 desktop (30%), 4 tablet (17%). Single-table GROUP BY — the simplest aggregation pattern.
Success check
Returns the complete deterministic result for users by device type
Expected result
Use this output to verify values, aliases, ordering, and row count.
| device_type | user_count |
|---|---|
| mobile | 13 |
| desktop | 7 |
| tablet | 4 |
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