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The Shadow Follower

Mission brief

Challenge Briefing

Hard

Subqueries
NOT IN
GROUP BY
HAVING

The Marketing team is tracking a new trend of "Silent Consumers"—users who follow many accounts to watch from the shadows without ever building a following of their own. To refine our user engagement metrics, we need to identify these specific "lurker" accounts.

The Shadow Follower

Identify "lurker" accounts that follow many users but have zero followers.

The Narrative

Schema Diagram

users

idINT

usernameVARCHAR

follows

follower_idINT

followee_idINT

Challenge a Friend

One SQL table. One SQL condition.
Still tricky for most developers.

SQL Editor

Terminal Output

Initializing Database Engine v1.8.0...

Write a SQL query, then click Run Query

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