Database validation is a common part of analytics engineering, ETL testing, and production data quality checks. Interviewers ask this to understand whether you can use SQL to confirm that data is complete, accurate, and consistent.
Describe your experience using SQL for database validation. In your answer, explain how you would use SQL to:
Keep the discussion practical rather than theoretical. The interviewer expects a structured explanation of the most common validation patterns, the SQL queries you would write, what issues they catch, and how you would prioritize checks in a real workflow.