Reactivated Users After Churn

SQLHardSenior levelMeta~15 min

Problem

**[Asked at Meta]**

A user "reactivates" when they log in after a gap of **more than 30 days**.
Find all users who have reactivated at least once. Return `user_id`, ordered ascending.

Tables

Example rows — the live problem includes the full dataset.

logins

login_id	user_id	login_date

Expected output

Your answer should return 2 rows with the columns user_id.

Starter code (SQL)

SELECT *
FROM logins;

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Solution & explanation

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