IS213_Module2-QUIZ_Understanding Database Relationships

What are the four main types of cardinality?

• Many-to-Some

• One-to-Two

• Two-to-Many

• One-to-One, One-to-Many, Many-to-One, Many-to-Many

Define one-to-one cardinality with an example.

• In a one-to-one relationship, each student is assigned a unique student ID.

• Each student can share the same student ID.

• Student IDs are randomly generated without uniqueness.

• A student ID can be assigned to multiple students.

Define one-to-many cardinality with an example.

• A city can have many countries, illustrating one-to-many cardinality.

• A car can have many owners, illustrating one-to-many cardinality.

• In a database, an author can have many books, illustrating one-to-many cardinality.

• A student can enroll in many courses, illustrating one-to-many cardinality.

Define many-to-one cardinality with an example.

• Many classes can have one student.

• In a student-class relationship, many students can belong to one class.

• Each class has only one student.

• One student can belong to many classes.

Define many-to-many cardinality with an example.

• Many-to-one cardinality is a relationship where multiple records in one entity are related to a single record in another entity, such as students to a school.

• Many-to-many cardinality is a relationship where multiple records in one entity are related to multiple records in another entity, such as students and courses.

• One-to-one cardinality is when one record in an entity is related to one record in another entity, like a person and their passport.

• One-to-many cardinality is when one record in an entity is related to multiple records in another entity, like a teacher and their students.

What does optionality in a relationship refer to?

• Optionality in a relationship is about avoiding any emotional connection.

• Optionality in a relationship refers to the flexibility and choice individuals have in their level of commitment and engagement.

• Optionality means having a fixed commitment to one partner.

• Optionality refers to the exclusivity of a relationship.

How does optionality affect the design of a database?

• Optionality allows for flexible data modeling, accommodating varying data inputs while impacting normalization and data integrity.

• Optionality simplifies the database structure by removing relationships.

• Optionality eliminates the need for data validation.

• Optionality restricts data types to a single format.

What is the difference between mandatory and optional relationships?

• Both mandatory and optional relationships are the same.

• Optional relationships require a strict association.

• Mandatory relationships are always optional.

• Mandatory relationships require an association; optional relationships do not.

What is an example of a mandatory relationship in a database?

• A 'Student' must be enrolled in at least one 'Course'.

• A 'Library' must have at least one 'Book' available.

• A 'Teacher' must teach at least one 'Subject'.

• A 'Course' can exist without any 'Student'.

What is an example of an optional relationship in a database?

• A customer must have at least one order.

• A product can exist without any categories.

• A customer may exist without any orders.

• An employee must be assigned to a department.