Chapter 3 - Relational Database Schema

1. What is an entity in a relational database?

• A row in a table

• A column in a table

• An object or thing in the real world with distinct attributes

• A relationship between two tables

Which of the following is an example of an attribute in a relational database?

• A table name

• A column in a table

• A relationship between two tables

• A primary key

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

• To allow duplicate values in a table

• To uniquely identify each record in a table

• To establish a relationship between two tables

• To store foreign keys

What is a foreign key in a relational database?

• A key that uniquely identifies rows in a table

• A key that links rows between two tables

• A key that enforces data integrity within a single table

• A key that encrypts data in a table

Which of the following best describes a relationship in a relational database?

• A connection between attributes in a table

• A connection between rows in the same table

• A connection between two or more tables based on common attributes

• A connection between primary and foreign keys in the same table

Which of the following is NOT a type of key in a relational database?

• Composite key

• Candidate key

• Primary key

• Functional key

What is a composite key in a relational database?

• A foreign key that references another table

• A key formed by combining two or more attributes to uniquely identify a row

• A key that allows duplicate values

• A key that is automatically generated

Which of the following attributes is most suitable to be a primary key?

• A person's name

• A person's email address

• A person's date of birth

• A unique identification number

What is the relationship type where one entity is associated with multiple records in another entity?

• One-to-One

• One-to-Many

• Many-to-Many

• Self-Referencing

Which of the following is true about candidate keys?

• They must always be foreign keys

• They are attributes that can uniquely identify rows in a table

• They can have duplicate values

• They are used only for establishing relationships