Databases · Middle · Question 55 of 75
What is third normal form (3NF), roughly?
- 1Every table has exactly three columns
- 2Every query uses at most three joins
- ✓Correct answer: Every non-key column depends only on the key, not on other non-key columns
Explanation
If orders stores customer_id and customer_city, the city depends on the customer, not the order, so it belongs in customers.