Database Modeling and Design MCQs with Answers
Practice important Database Modeling and Design MCQs with answers and explanations.
Chapter: 9
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
Correct Answer:
A
Chapter: 9
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
Correct Answer:
B
Chapter: 9
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
Correct Answer:
A
Chapter: 9
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
Correct Answer:
D
Chapter: 9
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
Correct Answer:
A
Chapter: 9
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
Correct Answer:
A
Chapter: 10
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
Correct Answer:
A
Chapter: 10
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
Correct Answer:
B
Chapter: 10
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
Correct Answer:
B
Chapter: 10
Q150:
Which of the following is a property of Super and Sub Types?
A. Isolation
B. Exhaustive
C. Partial Inheritance
D. Dynamic Relationship
Correct Answer:
B
Chapter: 10
Q151:
According to the Exhaustive property, a valid subtype must have:
A. No attributes
B. One or more specific attributes
C. All attributes shared with super type
D. Mutually exclusive attributes
Correct Answer:
B
Chapter: 10
Q152:
The rule stating that subtypes do not share relationships or attributes with each other is called:
A. Isolation
B. Mutually Exclusive
C. Exhaustive
D. Super-Sub Dependency
Correct Answer:
B
Chapter: 10
Q153:
If sno=1 is associated with Full-time employee, can it also be associated with Part-time employee?
A. Yes
B. No
C. Sometimes
D. Only if mutually exclusive is off
Correct Answer:
B
Chapter: 10
Q154:
In a HR system, which type of employee is eligible for loan facilities?
A. Part-time
B. Full-time
C. Contract-based
D. All employees
Correct Answer:
B
Chapter: 10
Q155:
Fill in the blank: Super types cannot access the _____ of subtypes.
A. attributes
B. relationships
C. properties
D. attributes and relationships
Correct Answer:
D
Chapter: 10
Q156:
According to EERD, what happens when Salary attribute is removed from the Full-time subtype?
A. It becomes invalid
B. It remains valid
C. It shares with the Part-time subtype
D. It gets inherited from the super type
Correct Answer:
A
Chapter: 10
Q157:
The EERD model extends which diagram?
A. Unified Modeling Diagram
B. Class Diagram
C. Entity Relationship Diagram
D. Database Flow Diagram
Correct Answer:
C
Chapter: 10
Q158:
Fill in the blank: A subtype that has no specific attributes is considered ________.
A. redundant
B. invalid
C. valid
D. dynamic
Correct Answer:
B
Chapter: 10
Q159:
What is another name for a Super Type?
A. Subclass
B. Entity Relationship
C. Super Class
D. Super Database
Correct Answer:
C
Chapter: 10
Q160:
Which of the following statements is TRUE regarding EERD?
A. Super types can access all subtypes' relationships.
B. Subtypes inherit attributes from super types.
C. Subtypes know about each other’s relationships.
D. Super types depend on subtypes for attributes.
Correct Answer:
B