No Gaps

A easy SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

easy

Problem

The email marketing team is preparing a campaign blast and needs a clean contact list with no blank fields. For each user, show their username, email address (substituting 'unknown' if the email is missing), and age bucket (substituting 'unspecified' if the age bucket is missing). Only include users whose account is currently active.

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a live PostgreSQL database and grades it instantly.