C175 FINAL EXAM PREP QUESTIONS
WITH VERIFIED ANSWERS AND
DETAILED EXPLANATIONS. 2026/2027
1. Which normal form requires the removal of transitive dependencies, ensuring that every
non-prime attribute is functionally dependent only on the primary key?
A. Third Normal Form (3NF)
B. Second Normal Form (2NF)
C. First Normal Form (1NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Third Normal Form (3NF) requires a table to be in 2NF and have
no transitive dependencies, meaning non-key attributes must depend only on the primary
key, not on other non-key attributes.
2. In an Entity-Relationship Diagram (ERD), what does a dashed line between two entities
typically represent in some notations?
A. A non-identifying relationship
,B. A strong relationship
C. A many-to-many relationship
D. A recursive relationship
Answer: A
Conceptual Explanation: In many ERD notations like Crow’s Foot, a dashed line
represents a non-identifying relationship where the child entity can be uniquely identified
without the parent.
3. Which SQL clause is used to filter results based on the result of an aggregate function?
A. WHERE
B. GROUP BY
C. HAVING
D. ORDER BY
Answer: C
Conceptual Explanation: The HAVING clause was added to SQL because the WHERE
keyword could not be used with aggregate functions.
4. A relation is in Second Normal Form (2NF) if it is in 1NF and what other condition is met?
A. There are no multi-valued attributes.
B. Every non-prime attribute is fully functionally dependent on the entire primary key.
, C. There are no transitive dependencies.
D. There are no candidate keys.
Answer: B
Conceptual Explanation: 2NF requires that there are no partial functional dependencies;
every non-key attribute must depend on the whole primary key, not just part of it.
5. What is the purpose of a ‘Foreign Key’ in a relational database?
A. To uniquely identify a row in its own table.
B. To store encrypted sensitive data.
C. To speed up data retrieval.
D. To enforce referential integrity between two tables.
Answer: D
Conceptual Explanation: A foreign key is a column or group of columns in one table that
provides a link between data in two tables, ensuring referential integrity.
6. Which command is used to remove all records from a table without deleting the table
structure itself?
A. TRUNCATE
B. DROP
C. DELETE
WITH VERIFIED ANSWERS AND
DETAILED EXPLANATIONS. 2026/2027
1. Which normal form requires the removal of transitive dependencies, ensuring that every
non-prime attribute is functionally dependent only on the primary key?
A. Third Normal Form (3NF)
B. Second Normal Form (2NF)
C. First Normal Form (1NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Third Normal Form (3NF) requires a table to be in 2NF and have
no transitive dependencies, meaning non-key attributes must depend only on the primary
key, not on other non-key attributes.
2. In an Entity-Relationship Diagram (ERD), what does a dashed line between two entities
typically represent in some notations?
A. A non-identifying relationship
,B. A strong relationship
C. A many-to-many relationship
D. A recursive relationship
Answer: A
Conceptual Explanation: In many ERD notations like Crow’s Foot, a dashed line
represents a non-identifying relationship where the child entity can be uniquely identified
without the parent.
3. Which SQL clause is used to filter results based on the result of an aggregate function?
A. WHERE
B. GROUP BY
C. HAVING
D. ORDER BY
Answer: C
Conceptual Explanation: The HAVING clause was added to SQL because the WHERE
keyword could not be used with aggregate functions.
4. A relation is in Second Normal Form (2NF) if it is in 1NF and what other condition is met?
A. There are no multi-valued attributes.
B. Every non-prime attribute is fully functionally dependent on the entire primary key.
, C. There are no transitive dependencies.
D. There are no candidate keys.
Answer: B
Conceptual Explanation: 2NF requires that there are no partial functional dependencies;
every non-key attribute must depend on the whole primary key, not just part of it.
5. What is the purpose of a ‘Foreign Key’ in a relational database?
A. To uniquely identify a row in its own table.
B. To store encrypted sensitive data.
C. To speed up data retrieval.
D. To enforce referential integrity between two tables.
Answer: D
Conceptual Explanation: A foreign key is a column or group of columns in one table that
provides a link between data in two tables, ensuring referential integrity.
6. Which command is used to remove all records from a table without deleting the table
structure itself?
A. TRUNCATE
B. DROP
C. DELETE
