Database Management System MCQs with Answers
Practice important Database Management System MCQs with answers and explanations.
Multiple Choice Questions
Q231: The degree of a relation is defined as the number of _______ in that relation.
- A: rows
- B: tuples
- C: columns
- D: attributes
View Answer
C
Q232: In the STUDENT table example, what is the degree of the relation?
- A: Three
- B: Four
- C: Five
- D: Six
View Answer
B
Q233: The cardinality of a relation refers to the number of _______ present in the relation.
- A: columns
- B: tuples
- C: rows
- D: attributes
View Answer
C
Q234: In the given example, which attribute in the EMP table is a foreign key?
- A: empId
- B: empName
- C: qual
- D: depId
View Answer
D
Q235: What must match or be null for a foreign key to comply with referential integrity constraints?
- A: The primary key value in the home relation
- B: The domain value of the foreign key
- C: The primary key in the foreign relation
- D: The data type of the foreign key
View Answer
A
Q236: Which constraint ensures that no attribute of a primary key can have a null value?
- A: Entity Integrity Constraint
- B: Referential Integrity Constraint
- C: Null Constraint
- D: Default Value Constraint
View Answer
A
Q237: In a relational database, which constraint applies to attributes to ensure they are defined and have a value?
- A: Entity Integrity Constraint
- B: Referential Integrity Constraint
- C: Null Constraint
- D: Default Value Constraint
View Answer
C
Q238: What does a default value constraint do in a database?
- A: Ensures an attribute cannot be null
- B: Specifies a value for an attribute if none is provided
- C: Forces an attribute to have a unique value
- D: Limits the possible values of an attribute
View Answer
B
Q239: Domain constraints in databases specify the _______ of an attribute.
- A: possible set of values
- B: default value
- C: primary key value
- D: foreign key value
View Answer
A
Q240: Composite attributes in a relational database are treated as _______.
- A: simple attributes
- B: separate relations
- C: multi-valued attributes
- D: foreign keys
View Answer
B