Distinct Users with Web Requests | Dataford Interview Questions

A web analytics team wants to measure how many registered users made at least one iPhone request during the 2026 calendar year. Write a SQL query to return the distinct-user count.

Output

Return exactly one row with one column named iphone_user_count.
Count each registered user at most once, even if they made multiple qualifying requests.
Include only requests from the 2026 calendar year where device_type is exactly iPhone. Requests with other device types or NULL device types are excluded.

Schema

users

Column	Type	Description
user_idPK	INT	Unique identifier for a user
user_name	VARCHAR(100)	Display name of the user
signup_date	DATE	Date the user registered

web_requests

Column	Type	Description
request_idPK	INT	Unique identifier for a web request
user_id	INT	User who made the request
requested_at	TIMESTAMP	Timestamp when the request occurred
device_type	VARCHAR(50)	Device type used for the request

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