Database Basics Quiz

Jakey and Oliver are designing a database for their school project. What does an Entity-Relationship Diagram (ERD) represent in a database?

• The physical layout of the database

• The relationships between different entities in the database

• The user interface of the database

• The security settings of the database

Answer explanation

The relationships between different entities in the database

KayKay would like to know which of the following is a key principle of database design?

• Redundancy

• Normalisation

• Fragmentation

• Encryption

Answer explanation

The key principle of database design is Normalisation, which aims to reduce redundancy and improve data integrity by organizing data into tables and columns efficiently.

JimBobble is creating a database to keep track of his book collection. What is a primary key in his database?

• A key that can be used to unlock the database

• A unique identifier for each record in a table

• A key that links two tables together

• A key that encrypts the data

Answer explanation

A primary key in a database is a unique identifier for each record in a table, allowing for the identification and retrieval of specific data entries.

During a database design class, Alfie asked, 'What does a diamond shape typically represent in an ERD?'

• An entity

• An attribute

• A relationship

• A primary key

Answer explanation

A diamond shape in an ERD typically represents a relationship between entities, making it the correct choice.

Oliver is designing a database for a school project. Which of the following is an example of a foreign key?

• A unique identifier for a record in its own table

• A key that links to a primary key in another table

• A key that encrypts the data

• A key that is used to sort data

Answer explanation

A foreign key is a key that links to a primary key in another table, establishing a relationship between the two tables.

KayKay and NatNat are designing a database for their school project. What is the purpose of normalisation in database design?

• To increase redundancy

• To reduce data duplication

• To make the database larger

• To encrypt the data

Answer explanation

To reduce data duplication

In a school database, what does a rectangle typically represent in an ERD?

• An entity

• An attribute

• A relationship

• A primary key

Answer explanation

A rectangle in an ERD typically represents an entity, which is a real-world object or concept that is being modeled in the database.

KayKay and NatNat are working on a database project. Which of the following is NOT a type of relationship in an ERD?

• One-to-One

• One-to-Many

• Many-to-Many

• One-to-None

Answer explanation

The correct choice is One-to-None because it is not a valid type of relationship in an ERD. The other options (One-to-One, One-to-Many, Many-to-Many) are common relationship types in ERDs.

Massive and NatNat need to create a key made up of multiple attributes to uniquely identify each record. What is this type of key called?

• A key that is made up of multiple attributes

• A key that is used to encrypt data

• A key that is used to sort data

• A key that links two tables together

Answer explanation

A key that is made up of multiple attributes is called a composite key, which uniquely identifies each record by combining multiple attributes.

Oliver is designing a database for a school project. Which of the following best describes a foreign key constraint?

• It ensures that the value in a foreign key column matches a value in the primary key column of another table

• It ensures that the value in a primary key column is unique

• It ensures that the database is encrypted

• It ensures that the data is sorted

Answer explanation

It ensures that the value in a foreign key column matches a value in the primary key column of another table