SQL Window Ranking by Delay | Dataford Interview Questions

Write a SQL query using window functions to rank aircraft by monthly delay minutes within each airline and calculate a running total.

Use the provided airlines, aircraft, and flight_delays tables.

Output

Return one row per aircraft, airline, and month with airline_name, aircraft_id, month_start, monthly_delay_minutes, monthly_rank, and airline_running_delay_minutes.
Rank higher monthly delay totals first within each airline and month. Ties share a rank.
Order by airline_name, month_start, and monthly_rank.

airlines

Column	Type	Description
airline_idPK	INT	Unique airline identifier
airline_name	VARCHAR(100)	Airline name

aircraft

flight_delays

Column	Type	Description
delay_idPK	INT	Unique delay record identifier
aircraft_id	INT	Aircraft associated with the delay
flight_date	DATE	Date of the flight
delay_minutes	INT	Flight delay duration in minutes

Your question is SQL Window Ranking by Delay. Start with the requirements and the three tables in the Question tab.

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