IS 183
Database Concepts & Applications I
Midterms Exam Review (Qns & Ans)
2025
1. Which database normalization form eliminates duplicate data
by ensuring all non-key attributes depend only on the primary
key?
A. First Normal Form (1NF)
B. Second Normal Form (2NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
- ANS: C. Third Normal Form (3NF)
- Rationale: 3NF ensures that all attributes are functionally
dependent solely on the primary key, eliminating transitive
dependencies.
©2025
,2. What is the main purpose of an index in a relational database?
A. To enforce referential integrity
B. To improve query performance by speeding up data retrieval
C. To enforce primary key constraints
D. To handle transactions and rollbacks
- ANS: B. To improve query performance by speeding up
data retrieval
- Rationale: Indexes allow the database to locate rows faster,
optimizing query performance.
3. What is the function of a foreign key in relational database
management systems (RDBMS)?
A. To ensure data redundancy
B. To uniquely identify a row in a table
C. To establish and enforce relationships between two tables
D. To define a default value for a column
- ANS: C. To establish and enforce relationships between
two tables
- Rationale: A foreign key links rows in one table to rows in
another, maintaining referential integrity.
©2025
,4. Which of the following SQL clauses is used to remove
duplicate rows from a query result?
A. DISTINCT
B. GROUP BY
C. ORDER BY
D. LIMIT
- ANS: A. DISTINCT
- Rationale: The DISTINCT clause filters out duplicate rows,
ensuring the result contains only unique records.
5. What is the primary function of a database transaction?
A. To back up data
B. To execute multiple operations as a single atomic unit
C. To assign user roles
D. To update a database schema
- ANS: B. To execute multiple operations as a single atomic
unit
- Rationale: Transactions ensure that a group of database
operations are executed entirely or not at all, maintaining data
integrity.
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©2025
, Fill-in-the-Blank Questions
6. In a database, the __________ key uniquely identifies each
record in a table.
- ANS: Primary
- Rationale: A primary key ensures that each row in a table is
uniquely identifiable.
7. __________ is a type of SQL join that returns all rows from
both tables, with NULLs in place of missing matches.
- ANS: FULL OUTER JOIN
- Rationale: FULL OUTER JOIN retrieves unmatched rows
from both tables along with matched rows.
8. The __________ constraint ensures that a column cannot have
a NULL value in a relational database table.
- ANS: NOT NULL
- Rationale: The NOT NULL constraint enforces that a
column must always have a valid value.
9. __________ is a database language used to define,
manipulate, and query relational databases.
- ANS: SQL (Structured Query Language)
©2025
Database Concepts & Applications I
Midterms Exam Review (Qns & Ans)
2025
1. Which database normalization form eliminates duplicate data
by ensuring all non-key attributes depend only on the primary
key?
A. First Normal Form (1NF)
B. Second Normal Form (2NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
- ANS: C. Third Normal Form (3NF)
- Rationale: 3NF ensures that all attributes are functionally
dependent solely on the primary key, eliminating transitive
dependencies.
©2025
,2. What is the main purpose of an index in a relational database?
A. To enforce referential integrity
B. To improve query performance by speeding up data retrieval
C. To enforce primary key constraints
D. To handle transactions and rollbacks
- ANS: B. To improve query performance by speeding up
data retrieval
- Rationale: Indexes allow the database to locate rows faster,
optimizing query performance.
3. What is the function of a foreign key in relational database
management systems (RDBMS)?
A. To ensure data redundancy
B. To uniquely identify a row in a table
C. To establish and enforce relationships between two tables
D. To define a default value for a column
- ANS: C. To establish and enforce relationships between
two tables
- Rationale: A foreign key links rows in one table to rows in
another, maintaining referential integrity.
©2025
,4. Which of the following SQL clauses is used to remove
duplicate rows from a query result?
A. DISTINCT
B. GROUP BY
C. ORDER BY
D. LIMIT
- ANS: A. DISTINCT
- Rationale: The DISTINCT clause filters out duplicate rows,
ensuring the result contains only unique records.
5. What is the primary function of a database transaction?
A. To back up data
B. To execute multiple operations as a single atomic unit
C. To assign user roles
D. To update a database schema
- ANS: B. To execute multiple operations as a single atomic
unit
- Rationale: Transactions ensure that a group of database
operations are executed entirely or not at all, maintaining data
integrity.
---
©2025
, Fill-in-the-Blank Questions
6. In a database, the __________ key uniquely identifies each
record in a table.
- ANS: Primary
- Rationale: A primary key ensures that each row in a table is
uniquely identifiable.
7. __________ is a type of SQL join that returns all rows from
both tables, with NULLs in place of missing matches.
- ANS: FULL OUTER JOIN
- Rationale: FULL OUTER JOIN retrieves unmatched rows
from both tables along with matched rows.
8. The __________ constraint ensures that a column cannot have
a NULL value in a relational database table.
- ANS: NOT NULL
- Rationale: The NOT NULL constraint enforces that a
column must always have a valid value.
9. __________ is a database language used to define,
manipulate, and query relational databases.
- ANS: SQL (Structured Query Language)
©2025
