Database Modeling and Design MCQs with Answers
Practice important Database Modeling and Design MCQs with answers and explanations.
Multiple Choice Questions
Q141: In a One-to-One relationship, which rule applies to the foreign key?
- A: It must be a unique key in one of the tables
- B: It must be NULL
- C: It can appear multiple times
- D: It is the primary key of both tables
View Answer
A
Q142: Which of the following can be a Composite Primary Key (CPK) in the receipt scenario?
- A: Receipt ID and Date
- B: Receipt ID and Apartment Number
- C: Receipt ID and Customer ID
- D: None of the above
View Answer
B
Q143: What does cardinality describe in a relationship?
- A: Minimum and maximum occurrences of related entity
- B: Whether the relationship is optional or not
- C: Identifying the primary key
- D: Determining the unique keys
View Answer
A
Q144: How is optionality defined in a parent-child relationship?
- A: A parent must always have a child record
- B: A child record must always have a parent record
- C: There is no relationship between entities
- D: A child may or may not have a parent
View Answer
D
Q145: In the apartment rental scenario, which entity could be associated with a foreign key in the receipt table?
- A: Customer
- B: Building
- C: Apartment
- D: Receipt
View Answer
A
Q146: What is the primary difference between a unique key and a primary key?
- A: A unique key can contain NULL values
- B: A unique key must not contain duplicate values
- C: A primary key can be NULL
- D: A primary key can have duplicates
View Answer
A
Q147: What does EERD stand for?
- A: Extended Entity Relationship Diagram
- B: Extra Entity Relationship Diagram
- C: Enhanced Entity Relationship Diagram
- D: Exclusive Entity Relationship Diagram
View Answer
A
Q148: What is the purpose of a Super Type in EERD?
- A: To define sub-type attributes
- B: To avoid redundancy of attributes
- C: To create bottom-up relationships
- D: To isolate subtypes
View Answer
B
Q149: In EERD, a subtype can inherit attributes from which entity?
- A: Another subtype
- B: A super type
- C: An external entity
- D: An unrelated entity
View Answer
B
Q150: Which of the following is a property of Super and Sub Types?
- A: Isolation
- B: Exhaustive
- C: Partial Inheritance
- D: Dynamic Relationship
View Answer
B