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The Basics of Creating Tables in SQL

Primary keys – the basics
Single-column primary keys
Multi-column primary keys
15. Uniqueness with multi-column primary keys – continued
NOT NULL
Review

Instruction

Nice! We have successfully inserted the new row since the combination title + year was unique.

But what happens if the combination of values is not unique? Let's find out.

Exercise

Run the template query, that tries to add a new movie where the combination title + year is the same as the combo in another row.