Database Management System MCQs with Answers
Practice important Database Management System MCQs with answers and explanations.
Multiple Choice Questions
Q151: Fill in the blank: The ________ relationship is an abstraction of a relationship and includes a set of relationship instances sharing common attributes.
- A: specific
- B: entity
- C: type
- D: relationship
View Answer
B
Q152: Fill in the blank: In an ER diagram, the continuous line connecting diamonds to rectangles indicates the ________ of the relationship.
- A: optional
- B: mandatory
- C: role
- D: participation
View Answer
B
Q153: Fill in the blank: A ________ key is chosen by the database designer to act as the primary means of identifying entity instances.
- A: super
- B: secondary
- C: candidate
- D: foreign
View Answer
C
Q154: What does the minimum cardinality indicate in an ER model?
- A: Maximum number of instances
- B: Minimum number of instances
- C: Optional or compulsory link
- D: Number of entities
View Answer
C
Q155: In a one-to-many relationship, what does "one" represent?
- A: One entity on both sides
- B: One entity on one side and many on the other
- C: Many entities on both sides
- D: Many entities on one side and one on the other
View Answer
B
Q156: Which notation is used to represent cardinalities in ER diagrams with arrows?
- A: Crow's foot notation
- B: Arrow-head notation
- C: Alphabetical notation
- D: Dot-based notation
View Answer
B
Q157: What type of relationship is described when an entity is associated with itself?
- A: Binary relationship
- B: Unary relationship
- C: Ternary relationship
- D: N-ary relationship
View Answer
B
Q158: What does "existence dependency" imply in an ER model?
- A: Entity instances are optional
- B: Entity instances must exist in both entities
- C: Entity instances must exist in one entity
- D: Entity instances are not linked
View Answer
C
Q159: How is a role in a recursive relationship typically represented?
- A: By connecting different entity types
- B: By labeling lines with roles
- C: By using multiple relationships
- D: By showing cardinalities
View Answer
B
Q160: Which dependency type involves a key from a parent entity used in a dependent entity?
- A: Identifier dependency
- B: Referential dependency
- C: Existence dependency
- D: Foreign key dependency
View Answer
B