SQL Window Streak of QuickBooks Logins | Dataford Interview Questions

Your question is SQL Window Streak of QuickBooks Logins. Start with the requirements and the two tables on the right.

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Problem

Intuit wants to identify continuous daily login streaks for users of QuickBooks. Write a PostgreSQL query that detects each uninterrupted sequence of login dates and excludes streaks shorter than two days.

Requirements

Treat multiple QuickBooks login events by the same user on the same calendar date as one login day.
Use a window function such as ROW_NUMBER, LAG, or LEAD to identify consecutive date sequences.
Return each qualifying streak's user, start date, end date, and number of consecutive login days.
Include only streaks of at least two days and order the results by user ID and streak start date.

Schema

quickbooks_users

Column	Type	Description
user_idPK	INTEGER	Unique QuickBooks user identifier
display_name	VARCHAR(100)	User's display name
email	VARCHAR(255)	User email address

quickbooks_login_events

Column	Type	Description
login_event_idPK	INTEGER	Unique login event identifier
user_id	INTEGER	References quickbooks_users.user_id
login_date	DATE	Calendar date of the login
login_source	VARCHAR(30)	Login channel, when available