Your question is Understanding Primary Keys in Databases. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
What is a primary key in a relational database? Discuss its role in ensuring data integrity and how it differs from other types of keys. Include examples of when and why to use primary keys in your database schema.