SQL Quiz

Pass with 7 / 10 to unlock your certificate.

1. 1. Which clause filters rows BEFORE grouping?

   HAVINGWHEREGROUP BYORDER BY

2. 2. Which JOIN returns rows even when there is no match on the right?

   INNER JOINLEFT JOINCROSS JOINFULL JOIN

3. 3. What does NORMALIZATION primarily reduce?

   Query timeData redundancyIndex sizeStorage cost

4. 4. Which key uniquely identifies a row?

   FOREIGN KEYINDEXPRIMARY KEYCANDIDATE KEY

5. 5. Which is NOT a SQL aggregate function?

   SUMAVGJOINCOUNT

6. 6. What does ACID stand for?

   Atomicity, Consistency, Isolation, DurabilityAccess, Cache, Index, DataAtomic, Concurrent, Independent, DirectAudit, Commit, Idempotent, Done

7. 7. Which statement permanently removes a table?

   DELETETRUNCATEDROPREMOVE

8. 8. Which operator tests for a value in a list?

   BETWEENINEXISTSLIKE

9. 9. What is a transaction?

   A stored procedureA logical unit of work executed atomicallyA type of indexA backup file

10. 10. Which clause limits the number of rows returned in standard SQL?

    TOPROWNUMFETCH FIRST n ROWSLIMIT n (MySQL/Postgres only)