2.2 - Relational Databases & SQL Basics

Question 1

Why are relational databases important in data analysis?

Answer 1

They store large datasets in an organized way, allowing you to query and analyze data efficiently.

Question 2

What is SQL and why is it useful?

Answer 2

SQL (Structured Query Language) is used to communicate with databases to retrieve, filter, and manipulate data.

Question 3

Name the main components of a relational database.

Answer 3

Tables, rows (records), columns (fields), keys

Question 4

A ______ is a collection of related data organized into rows and columns.

Answer 4

Table

Question 5

A ______ uniquely identifies each record in a table.

Answer 5

Primary key

Question 6

A ______ links a field in one table to a primary key in another table.

Answer 6

Foreign key

Question 7

Which of these is an example of a primary key?
A) Customer ID
B) Customer Name
C) City
D) Purchase Amount

Answer 7

A) Customer ID

Question 8

What is the purpose of a foreign key?

Answer 8

To create a relationship between two tables, allowing data to be linked logically.

Question 9

Name one benefit of using relational databases over spreadsheets.

Answer 9

Handles large datasets, enforces data integrity, supports complex queries, avoids redundancy.

Question 10

Which SQL command is used to retrieve data from a table?
A) INSERT
B) SELECT
C) UPDATE
D) DELETE

Answer 10

B) SELECT

Question 11

SQL commands like SELECT, WHERE, and JOIN are used to ______ data.

Answer 11

Query / retrieve / filter

Question 12

Why is understanding relational concepts important before writing SQL queries?

Answer 12

It helps you know how tables are connected and how to retrieve meaningful insights without errors.