Entity Relationship Model

What is an Entity Relationship Diagram?

• An Entity Relationship Diagram is a relationship between properties of entities in a database.

• An Entity Relationship Diagram is a type database table connections.

• An Entity Relationship Diagram is a type of database programming.

• An Entity Relationship Diagram (ERD) is a visual representation of the relationships between entities in a database.

What is represented by a rectangle in an entity-relationship diagram?

• Entity
• Database
• Attribute
• Relationship

In an ERD, what does a diamond-shaped symbol represent?

• Relationship
• Cardinality
• Entity
• Attribute

Which of the following is not a cardinality constraint used in ER diagrams?

• One-to-One

• Many-to-Many

• One-to-Many

• All-to-All

What does the crow's foot notation in an ERD signify?

• Many relationship
• Foreign key
• Primary key
• One-to-one relationship

What does the line connecting two entities in an ERD represent?

• Link
• Relationship
• Association
• Connection

In an ERD, what does a double rectangle represent?

• Primary key
• Foreign key
• Weak entity
• Attribute

What is the purpose of an ERD's cardinality constraints?

• To determine the data types of attributes in a database model.
• To specify the primary keys of entities in a database model.
• To define the order of records in a database model.
• To define the relationships between entities in a database model.

Which of the following is true regarding a composite attribute in an ERD?

• A composite attribute cannot have sub-parts.
• A composite attribute is always a single value.
• A composite attribute can be divided into smaller sub-parts.
• A composite attribute cannot be represented in an ERD.

In an ERD, what is the cardinality notation for a One-to-Many relationship?

• diamond
• arrow
• circle
• 1 - crows foot