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SQL and Data Manipulation Background
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SQL and Data Manipulation Background

MediumSQL · PostgreSQL

Problem

Tell me about your experience with SQL and data manipulation, including the kinds of questions you’ve used SQL to answer.

For this hands-on exercise, write a PostgreSQL query using the provided tables to produce a user-level activity summary for January 2025.

Output

  1. Return one row per user, including users without qualifying activity.
  2. Include user_id, display_name, event_count, total_event_value, latest_event_at, and activity_status.
  3. Order by user_id ascending. Activity status should distinguish inactive users, users with one event, and users with at least two events.

Schema

users
ColumnTypeDescription
user_idPKINTUnique user identifier
display_nameVARCHAR(100)User display name
user_events
ColumnTypeDescription
event_idPKINTUnique event identifier
user_idINTUser associated with the event
event_typeVARCHAR(50)Type of user event
event_atTIMESTAMPTimestamp when the event occurred
event_valueNUMERIC(10,2)Numeric value associated with the event
Tablesusersuser_events
Interviewer

Your question is SQL and Data Manipulation Background. 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.

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CodePostgreSQL
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