P55SQLIntermediateDesign14 min

Design a Window-Function Query for Latest Subscription Status

Return each user's latest subscription state while retaining plan history.

#design#window-functions#subscriptions

Scenario

subscription_events has user_id, event_at, plan, and status. Users can upgrade, pause, and cancel over time.

Problem statement

Design a query that returns the latest row per user.

Your Task

  1. Rank events within user.
  2. Select only rank one for current status.
  3. Explain how history remains available.

Related Concepts

ROW_NUMBEREvent historyLatest record

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