PostgreSQL quiz

Test your PostgreSQL knowledge with a free interactive quiz — 46 questions with answers and explanations. No signup needed to play.

What is a NULL value in SQL?

1. What is a NULL value in SQL?
2. What is the difference between `WHERE` and `HAVING`?
3. What does `ON CONFLICT` do in PostgreSQL?
4. What does ACID stand for in database transactions?
5. What is `COALESCE()` in PostgreSQL?
6. What is normalization in database design?
7. What is a schema in PostgreSQL?
8. What does `ORDER BY` do?
9. What is `SERIAL` in PostgreSQL?
10. What does `DISTINCT` do in a SELECT query?
11. What are the main SQL statement categories?
12. What is the difference between `CHAR`, `VARCHAR`, and `TEXT` in PostgreSQL?

More quizzes