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Time to next event per user

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Time to next event per user

For each event, return the next event's timestamp for the same user and the seconds between them. The last event per user gets NULL for both.

Use strftime(event_ts, '%Y-%m-%d %H:%M:%S') to stringify timestamps for grading stability.

Columns: user_id, strftime(event_ts, '%Y-%m-%d %H:%M:%S') AS event_ts, strftime(LEAD(event_ts) OVER (...), '%Y-%m-%d %H:%M:%S') AS next_ts, seconds_to_next. Sort by user_id then event_ts ascending.

Tables & sample data

events

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query.sql

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