Microsoft-style Company ChallengeMediumVerified answerSQLite live

Users with Support Tickets

Which users have raised at least one support ticket?

  • Sorting
  • Distinct values

Challenge brief

Understand the request

CRM Team needs a deduplicated list of all users who have ever submitted a support ticket for retargeting in a satisfaction survey.

List distinct user_ids who appear in support_tickets.

Return

  • user_id

Constraints

  • Return each qualifying user once
  • Order by user ID

Data you will use

Review the relevant tables before deciding how to join, filter, or aggregate them.

support_tickets

  • ticket_idINTEGER
  • user_idINTEGER
  • product_idINTEGER
  • created_dateDATE
  • statusTEXT

Hints, when you need them

Open one clue at a time so you still do the reasoning.

Hint 1

All ticket data is in support_tickets. You need unique user IDs — use SELECT DISTINCT to deduplicate in case a user has multiple tickets.

Hint 2

SELECT DISTINCT user_id FROM support_tickets.

Hint 3

Build question 16 from the required result grain: choose the driving table, add only the joins and filters needed for that grain, then apply aggregation and deterministic ordering.

Verified SQL answer

Attempt the problem first, then compare structure and reasoning—not just syntax.

Reveal solution and explanation
SELECT DISTINCT user_id FROM support_tickets ORDER BY user_id;

Why this works

In this dataset every user has exactly one ticket, so DISTINCT makes no difference. In production with multiple tickets per user, DISTINCT would collapse duplicates. All 12 users appear.

Success check

12 users — all users in the dataset have exactly 1 ticket each

Expected result

Use this output to verify values, aliases, ordering, and row count.

user_id
1
2
3
4
5
6
7
8
9
10

Previewing 10 of 12 expected rows. Run the query in the editor to inspect the full result.

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