SQL Quiz Test Online (30 random Questions) 2025

This quick 30-minute challenge consists of 30 random multiple-choice questions designed to test your knowledge across various SQL topics, including the introduction to databases, data manipulation and querying, database design and normalization, advanced SQL concepts, and database administration and security. Whether you’re a beginner or looking to expand your SQL expertise, this quiz will enhance your understanding of database management and querying skills.

0 votes, 0 avg

You have 30 minutes to complete the quiz. The timer will start when you click the 'Start Quiz' button. Please ensure you are ready before beginning.

Time is up! Your quiz has ended. Your responses have been submitted automatically.

30 Minutes SQL Quiz Test Online

Welcome to the SQL Quiz! This quick 30-minute challenge consists of 30 random multiple-choice questions designed to test your knowledge across various SQL topics, including the introduction to databases, data manipulation and querying, database design and normalization, advanced SQL concepts, and database administration and security. Whether you're a beginner or looking to expand your SQL expertise, this quiz will enhance your understanding of database management and querying skills.

1 / 30

1. How can unauthorized database access be prevented?

A) By implementing firewalls

B) All of the above

C) By enforcing strong authentication methods

D) By regularly updating security patches

2 / 30

2. What is a 'transaction log' in database management?

A) A record of all changes made to the database

B) A record of all database queries

C) A method for locking tables

D) A schema for normalization

3 / 30

3. Which command is used to create a new table in a database?

A) CREATE TABLE

B) NEW TABLE

C) INSERT

D) ADD TABLE

4 / 30

4. How does database mirroring enhance security?

A) By auditing user activities

B) By preventing SQL injection

C) By replicating data to a standby server

D) By encrypting data

5 / 30

5. Which normal form eliminates partial dependency?

A) 2NF

B) 3NF

C) 1NF

D) BCNF

6 / 30

6. Which SQL command is used to create a user?

A) ADD USER

B) CREATE USER

C) INSERT USER

D) NEW USER

7 / 30

7. What is the first step in database normalization?

A) Removing foreign keys

B) Adding composite keys

C) Ensuring all columns are atomic

D) Eliminating redundant data

8 / 30

8. What does the term 'two-factor authentication' (2FA) mean?

A) Authenticating two users simultaneously

B) Using two levels of encryption

C) Verifying identity with two methods (e.g., password and OTP)

D) Using two databases for authentication

9 / 30

9. What does the LIKE operator do?

A) Deletes records

B) Matches a pattern in a string

C) Sorts data

D) Joins tables

10 / 30

10. Which keyword is used to match patterns in SQL?

A) PATTERN

B) LIKE

C) SEARCH

D) MATCH

11 / 30

11. How do you add a new column to an existing table?

A) ADD COLUMN

B) UPDATE TABLE

C) ALTER TABLE

D) INSERT COLUMN

12 / 30

12. What is the primary purpose of a database schema?

A) To grant user permissions

B) To store backup files

C) To define the structure of the database

D) To execute SQL queries

13 / 30

13. Which type of dependency exists when a non-prime attribute depends on another non-prime attribute?

A) Partial dependency

B) Multivalued dependency

C) Circular dependency

D) Transitive dependency

14 / 30

14. What is the primary role of a database administrator (DBA)?

A) Writing application code

B) Developing mobile applications

C) Designing user interfaces

D) Managing and securing the database system

15 / 30

15. What is a composite key?

A) A temporary key

B) A key used for indexing

C) A primary key consisting of multiple columns

D) A foreign key with a single column

16 / 30

16. Which aggregate function calculates the sum of a column?

A) SUM()

B) COUNT()

C) AVG()

D) MAX()

17 / 30

17. What does a foreign key represent in a database?

A) A key that cannot be used

B) A unique identifier for each record

C) A reference to a primary key in another table

D) A default value for columns

18 / 30

18. What is a database index?

A) None of the above

B) A pointer to data in a table

C) A duplicate of a table

D) A key for foreign table linking

19 / 30

19. What is the purpose of the UNION operator?

A) Joins tables

B) Filters duplicate rows

C) Deletes records

D) Combines results of two queries

20 / 30

20. What is the difference between DELETE and TRUNCATE?

A) DELETE resets indexes; TRUNCATE does not

B) DELETE removes all rows; TRUNCATE removes specific rows

C) DELETE removes specific rows; TRUNCATE removes all rows

D) DELETE is faster than TRUNCATE

21 / 30

21. In database design, what does 'schema' refer to?

A) The structure of a database, including tables and relationships

B) A graphical representation of data

C) A query optimization technique

D) A database backup method

22 / 30

22. What is the purpose of a Common Table Expression (CTE)?

A) To optimize indexing

B) To perform transactions

C) To create temporary tables

D) To simplify complex queries by defining a temporary result set

23 / 30

23. What is functional dependency in a database?

A) A function that manages data

B) A dependency between primary keys

C) A relationship between two tables

D) A relationship between two columns

24 / 30

24. How do you combine data from multiple tables?

A) JOIN

B) GROUP BY

C) CONNECT

D) UNION

25 / 30

25. What is the purpose of the ROW_NUMBER() function?

A) Creates a unique index

B) Assigns ranks with gaps for duplicates

C) Calculates the total number of rows in a table

D) Assigns unique numbers to rows within a partition

26 / 30

26. What does the term 'role-based access control' (RBAC) mean?

A) Backing up the database

B) Granting access based on predefined roles

C) Encrypting sensitive data

D) Assigning permissions to individual users

27 / 30

27. What type of dependency does 3NF eliminate?

A) Circular dependency

B) Multivalued dependency

C) Partial dependency

D) Transitive dependency

28 / 30

28. Which normal form is achieved when every determinant is a candidate key?

A) BCNF

B) 5NF

C) 3NF

D) 4NF

29 / 30

29. Which SQL command is used to modify a user's password?

A) ALTER USER

B) MODIFY PASSWORD

C) UPDATE PASSWORD

D) CHANGE PASSWORD

30 / 30

30. Which operator is used to combine the results of two queries?

A) MERGE

B) CONNECT

C) UNION

D) JOIN

Your score is

The average score is 66%

Rate Your Experience!

Anonymous feedback

Thank you for your feedback! We appreciate your input.

10 Minutes Bootstrap Quiz Test Online

Online Quiz Test (with time limit)

JSON Quiz Test Online (30 random Questions)

10 Minutes Docker Quiz Test Online

10 Minutes MongoDB Quiz Test Online

MongoDB Quiz Test Online (30 random Questions)

Related