Top Users Per Region Query | Dataford Interview Questions

LinkedIn's Business Intelligence team wants to identify the most active members in each geographic region. Write a PostgreSQL query that counts member interactions and ranks members within their region.

Requirements

Join users to user_interactions and count interactions per member.
Exclude members whose region is unknown and members with no recorded interactions.
Return the top five members in each region, including ties only when they fall within the first five row numbers.
Order the output by region, activity rank, and member ID.

Schema

users

Column	Type	Description
user_idPK	INT	Unique LinkedIn member identifier
display_name	VARCHAR(100)	Member display name
region	VARCHAR(50)	Member reporting region

user_interactions

Column	Type	Description
interaction_idPK	INT	Unique interaction identifier
user_id	INT	Member who generated the interaction
interaction_type	VARCHAR(50)	Interaction category
occurred_at	TIMESTAMP	Interaction timestamp

Your question is Top Users Per Region Query. Start with the requirements and the two tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem