DBMS Multiple Choice Questions (MCQs)

1. DBMS Basics

1. DBMS stands for:
   A. Data Backup Management System
   B. Data Base Management System
   C. Database Machine System
   D. Data Build Management Software

   Answer: B

2. Which of the following is NOT a DBMS?
   A. MySQL
   B. Oracle
   C. MongoDB
   D. MS Word

   Answer: D

3. Which model stores data in table form?
   A. Network Model
   B. Hierarchical Model
   C. Relational Model
   D. Object Model

   Answer: C

2. Keys & Constraints

1. Which key uniquely identifies a record?
   A. Foreign Key
   B. Candidate Key
   C. Primary Key
   D. Composite Key

   Answer: C

2. Which constraint prevents NULL values?
   A. UNIQUE
   B. CHECK
   C. NOT NULL
   D. DEFAULT

   Answer: C

3. Foreign key is used to:
   A. Enforce uniqueness
   B. Connect two tables
   C. Prevent duplication
   D. Store default values

   Answer: B

3. SQL Commands

1. Which command is used to retrieve data?
   A. INSERT
   B. UPDATE
   C. SELECT
   D. DELETE

   Answer: C

2. Which SQL clause filters records?
   A. ORDER BY
   B. GROUP BY
   C. WHERE
   D. HAVING

   Answer: C

3. Which keyword removes duplicate values?
   A. DISTINCT
   B. UNIQUE
   C. PRIMARY
   D. DIFFERENT

   Answer: A

4. SQL Joins

1. Which join returns matching records from both tables?
   A. LEFT JOIN
   B. RIGHT JOIN
   C. FULL JOIN
   D. INNER JOIN

   Answer: D

2. Which join returns all rows from left table?
   A. INNER JOIN
   B. LEFT JOIN
   C. RIGHT JOIN
   D. SELF JOIN

   Answer: B

5. Aggregate Functions

1. Which function returns total rows?
   A. SUM()
   B. COUNT()
   C. AVG()
   D. MAX()

   Answer: B

2. Which clause is used with aggregate functions to filter groups?
   A. WHERE
   B. ORDER BY
   C. HAVING
   D. LIMIT

   Answer: C

6. Data Warehouse & Mining

1. Data Warehouse is mainly used for:
   A. Transaction processing
   B. Data entry
   C. Decision making
   D. Data deletion

   Answer: C

2. Which process extracts knowledge from data?
   A. Data Backup
   B. Data Mining
   C. Data Storage
   D. Data Transfer

   Answer: B

Practice Task