Chapter 4

What does an ERD primarily show?

• User interface layout

• Data types and formats

• Entities, attributes, and relationships

• Database backup plans

In ER modeling, a ‘Customer’ would be an example of a(n):

• Attribute

• Relationship

• Entity

• Primary key

Which of the following represents a weak entity?

• Entity with multiple attributes

• Entity with composite keys

• Entity that is existence-dependent and has partial key

• Entity that has a derived attribute

What does cardinality describe in ER modeling?

• The number of attributes

• The color of relationship lines

• The number of entity occurrences in a relationship

• The table row count

What type of relationship exists when an entity is related to itself?

• Binary

• Recursive

• Weak

• Ternary

Which attribute type can be broken down into smaller parts like ‘FullName’?

• Composite

• Simple

• Derived

• Primary

What is the role of a derived attribute?

• Stores large text

• Calculated from other attributes

• Always mandatory

• Defines relationships

In Crow’s Foot notation, relationships are represented using:

• Ovals

• Squares

• Lines with 'feet'

• Triangles

Which of the following would be a strong entity?

• Needs another entity to exist

• Exists independently

• Has no attributes

• Only stores foreign keys

A relationship involving three entities is called:

• Binary

• Ternary

• Unary

• Recursive