Master Database Design and SQL: Enhance Your Web Development Skills

Question 1

Which of the following is NOT a basic data type in SQL?

Accepted Answer

IMAGE

Answer

INTEGER

Answer

VARCHAR

Answer

BOOLEAN

Question 2

Which of the following is NOT a basic data type in SQL?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

BOOLEAN

Answer

STRING

Question 3

What is the correct SQL syntax to create a database called 'student_database'?

Accepted Answer

CREATE DATABASE student_database

Answer

CREATE DB student_database;

Answer

CREATE TABLE student_database;

Answer

DB CREATE student_database

Question 4

Which SQL data type is specifically designed for storing dates and times?

Accepted Answer

DATE

Answer

VARCHAR

Answer

INT

Answer

FLOAT

Question 5

Which of the following is NOT a fundamental data type in SQL?

Accepted Answer

ARRAY

Answer

INTEGER

Answer

STRING

Answer

BOOLEAN

Question 6

In a database table, what is the primary function of a primary key?

Accepted Answer

To uniquely identify each record within the table

Answer

To store the most critical information in the table

Answer

To establish connections between tables

Answer

To prevent the input of duplicate data

Question 7

In SQL, which command is used to create a new database?

Accepted Answer

CREATE DATABASE

Answer

CHANGE DATABASE

Answer

DELETE DATABASE

Answer

MODIFY DATABASE

Question 8

Explain the distinction between a WHERE clause and a HAVING clause in SQL.

Accepted Answer

A WHERE clause filters individual rows, while a HAVING clause filters groups of rows

Answer

A HAVING clause filters individual rows, while a WHERE clause filters groups of rows

Answer

Both clauses serve the same purpose

Answer

A WHERE clause filters columns, while a HAVING clause filters tables

Question 9

What is the primary function of a database schema?

Accepted Answer

To define the structure and organization of a database

Answer

To store and manage data within the database

Answer

To enforce data integrity and consistency

Answer

None of the aforementioned

Question 10

Which data type is most appropriate for storing a customer's name?

Accepted Answer

VARCHAR

Answer

INT

Answer

BOOLEAN

Answer

DATE

Question 11

Which SQL command is used to construct a new table?

Accepted Answer

CREATE TABLE

Answer

INSERT INTO

Answer

SELECT * FROM

Answer

UPDATE

Question 12

Which of the following is not a data manipulation language (DML) statement in SQL?

Accepted Answer

CREATE INDEX

Answer

INSERT

Answer

DELETE

Answer

UPDATE

Question 13

What is the purpose of a JOIN statement in SQL?

Accepted Answer

To merge rows from multiple tables based on common columns

Answer

To create a new table

Answer

To modify existing data in a table

Answer

To delete rows from a table

Question 14

Explain the distinction between an inner join and an outer join in SQL.

Accepted Answer

Inner join returns only matching rows, while outer join returns all rows from one table and matching rows from the other

Answer

Outer join returns only matching rows, while inner join returns all rows from one table and matching rows from the other

Answer

Both inner and outer joins return all rows from both tables

Answer

There is no difference between inner and outer joins

Question 15

What is the significance of a database schema?

Accepted Answer

To define the structure and relationships of data within a database

Answer

To store the actual data in a database

Answer

To regulate access to data in a database

Answer

To optimize query performance

Question 16

What is the primary purpose of a primary key in a database table?

Accepted Answer

To uniquely identify each row in the table

Answer

To enforce data integrity

Answer

To speed up data retrieval

Answer

To prevent unauthorized access to data

Question 17

Which SQL command is used to create a new database?

Accepted Answer

CREATE DATABASE

Answer

USE DATABASE

Answer

ALTER DATABASE

Answer

DROP DATABASE

Question 18

What is the difference between a WHERE clause and a HAVING clause in SQL?

Accepted Answer

WHERE filters rows before grouping, while HAVING filters groups after grouping

Answer

HAVING filters rows before grouping, while WHERE filters groups after grouping

Answer

WHERE and HAVING both filter rows before grouping

Answer

WHERE and HAVING both filter groups after grouping

Question 19

What is the purpose of a foreign key constraint in a database table?

Accepted Answer

To enforce referential integrity between tables

Answer

To prevent data duplication

Answer

To speed up data retrieval

Answer

To prevent unauthorized access to data

Question 20

What is the primary responsibility of a database management system (DBMS)?

Accepted Answer

To manage and control access to databases

Answer

To provide a user-friendly interface for interacting with databases

Answer

To optimize SQL queries

Answer

To prevent data loss

Question 21

What is the main difference between a join and a subquery in SQL?

Accepted Answer

Joins combine rows from multiple tables, while subqueries return a set of rows that can be used in another query

Answer

Subqueries combine rows from multiple tables, while joins return a set of rows that can be used in another query

Answer

Joins and subqueries both combine rows from multiple tables

Answer

Joins and subqueries both return a set of rows that can be used in another query

Question 22

Craft an SQL query that retrieves specific customer information while preserving data integrity. Describe how your query ensures data consistency and accuracy.

Accepted Answer

SELECT customerID, name, email FROM Customers WHERE city = 'London' AND active = 1;

Answer

SELECT * FROM Customers WHERE city = 'London';

Answer

SELECT * FROM Customers WHERE name LIKE '%John%';