Database Concepts Quiz

What does an ER diagram represent?

• Data flow in a network

• Relationships between data entities

• Operating system architecture

• Programming logic

In an ER diagram, what does a rectangle represent?

• Relationship

• Attribute

• Entity

• Foreign key

Which symbol represents a many-to-many (M:N) relationship?

• A single line

• A crows-foot notation on both sides

• A diamond shape

• A circle

What is the purpose of cardinality in an ER diagram?

• Defines the number of attributes in a table

• Determines how many relationships exist

• Specifies the number of entity instances that can be related

• Shows the primary key of an entity

What is a weak entity?

• An entity with a composite key

• An entity that cannot exist without a strong entity

• An entity with only one attribute

• A table with no relationships

What is a primary key?

• A unique identifier for each record in a table

• A key that connects two tables

• A key that allows duplicate values

• A randomly assigned number

Which key is used to establish relationships between tables?

• Primary Key

• Composite Key

• Foreign Key

• Candidate Key

In a relational database, what does a foreign key do?

• Ensures that values in a column are unique

• Creates duplicate records

• Links records between two tables

• Deletes records automatically

If an entity in Table A can be related to multiple records in Table B, but each record in Table B can relate to only one record in Table A, what type of relationship is this?

• One-to-One (1:1)

• One-to-Many (1:M)

• Many-to-Many (M:N)

• Recursive Relationship

Which of the following is an example of a one-to-one (1:1) relationship?

• A student enrolls in multiple courses

• A customer places multiple orders

• A country has only one official capital city

• A product is sold by multiple vendors