SQL Average Response Time | Dataford Interview Questions

A query platform wants to measure the response speed experienced by each user. Write a SQL query to calculate the average response time for completed queries submitted during the previous calendar month relative to September 15, 2026.

Output

One row per user with at least one completed query submitted during the previous calendar month.
Return user_id, user_name, and average_response_seconds, where the average is measured in seconds and rounded to two decimal places.
Exclude unanswered queries and query records without a matching user.
Sort by average response time descending, then user_id ascending to break ties.

Schema

users

Column	Type	Description
user_idPK	INT	Unique user identifier
user_name	VARCHAR(100)	Display name of the user

query_logs

Column	Type	Description
query_idPK	INT	Unique query log identifier
user_id	INT	User who submitted the query
submitted_at	TIMESTAMPTZ	Timestamp when the query was submitted
responded_at	TIMESTAMPTZ	Timestamp when a response was returned

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