Quiz: SQL, MySQL, NoSQL, and Databases

Question 1: What is the primary role of a database in a web application?

A. Styling the user interface B. Optimizing front-end performance C. Storing, managing, and retrieving data efficiently D. Handling server-side scripting

Question 2: Which of the following is a key benefit of using databases in modern applications?

A. Centralized data management B. Improved browser compatibility C. Faster loading times for CSS D. Increased page responsiveness

Question 3: What is a key feature of relational databases (SQL)?

A. Horizontal scalability B. Flexible schemas C. No need for indexing D. Predefined structured schemas with relationships

Question 4: Which of the following is an example of a NoSQL database?

A. MySQL B. PostgreSQL C. MongoDB D. Oracle Database

Question 5: What does the PRIMARY KEY constraint ensure in a relational database?

A. It allows duplicate values in a column. B. It uniquely identifies each row in a table. C. It creates a foreign key relationship. D. It automatically generates indexes for all columns.

Question 6: In NoSQL databases, what is a common use case for key-value stores?

A. Real-time analytics B. Managing relationships between users C. Caching and session storage D. Complex queries with joins

Question 7: Which of the following SQL queries retrieves all rows from a table named employees?

A. SELECT employees FROM *; B. GET * FROM employees; C. FETCH ALL employees; D. SELECT * FROM employees;

Question 8: Which feature makes NoSQL databases more flexible than SQL databases?

A. Dynamic schemas B. Fixed schemas C. Strict relationships D. High read consistency

Question 9: What is the purpose of normalization in relational databases?

A. To allow duplicate data for faster queries B. To optimize data storage and reduce redundancy C. To increase database security D. To simplify query syntax

Question 10: Which of the following is an example of a MongoDB query to find documents in a collection named users where the field age is greater than 25?

A. users.find(age > 25); B. db.users.find({ "age": { "$gt": 25 } }); C. SELECT * FROM users WHERE age > 25; D. db.users.search({ age > 25 });

Question 11: Which type of relationship is represented by a foreign key in a relational database?

A. One-to-One B. One-to-Many C. Many-to-Many D. Both A and B

Question 12: Which of the following is an example of a graph database?

A. Neo4j B. MongoDB C. DynamoDB D. PostgreSQL

Question 13: What is the best method to prevent SQL injection attacks?

A. Use dynamic queries with user input directly embedded B. Disable user input validation C. Use parameterized queries or prepared statements D. Allow unrestricted access to the database