Class 12 IT(802) - Database Concepts MCQs

🚀 Want to score high in Class 12 IT (802) without getting stuck in lengthy theory? Start with MCQs!

Practice these exam-oriented Database Concepts MCQs, test your concepts, identify weak areas, and revise the chapter quickly. Whether you are preparing for your board exam, school test, or quick revision, these questions will help you build confidence and improve your accuracy.

This collection of MCQs covers important concepts such as DBMS, RDBMS, relational model, tables, tuples, attributes, keys, SQL commands, data types, constraints, DDL, DML, and SQL queries.

🔥 So, don’t just read Database Concepts—test yourself and see how much you really know! Let’s begin.

Q1. A school records students’ marks and later calculates average, maximum and minimum marks. The calculated values represent:
a) Data
b) Metadata
c) Information
d) Domain

Q2. A collection of related data that has been recorded, organized and made available for searching is called a ______.
a) File
b) Database
c) Program
d) Query

Q3. If a teacher’s salary is changed in one table but not in another table containing the same information, the resulting problem is:
a) Data redundancy
b) Data inconsistency
c) Data integration
d) Data independence

Q4. A DBMS allows several users to access a database simultaneously. This capability is known as:
a) Database sharing
b) Database definition
c) Data redundancy
d) Data isolation

Q5. Protection against unauthorized access and software/hardware failures is associated with:
a) Database population
b) Database protection
c) Database definition
d) Database sorting

Q6. The description of the structure of data and constraints imposed on it is called:
a) Data
b) Metadata
c) Tuple
d) Cardinality

Q7. A person responsible for authorizing access, monitoring database use and providing technical support is the:
a) End user
b) Database Administrator
c) System analyst
d) Application programmer

Q8. Which of the following is an example of a DBMS?
a) MySQL
b) HTML
c) Python
d) CSS

Q9. The relational database model was developed by:
a) E.F. Codd
b) Charles Babbage
c) Dennis Ritchie
d) Tim Berners-Lee

Q10. In the relational model, a row is called a:
a) Relation
b) Tuple
c) Attribute
d) Domain

Q11. In a relational table, a column is known as an:
a) Attribute
b) Tuple
c) Relation
d) State

Q12. The relational-model term corresponding to a table is:
a) Tuple
b) Domain
c) Relation
d) Attribute

Q13. The set of possible values that an attribute can contain is its:
a) Degree
b) Cardinality
c) Domain
d) Schema

Q14. A relation has 7 attributes and 50 tuples. Its degree and cardinality respectively are:
a) 50 and 7
b) 7 and 50
c) 57 and 7
d) 7 and 57

Q15. The number of attributes in a relation determines its:
a) Cardinality
b) Degree
c) Domain
d) State

Q16. The number of tuples in a relation determines its:
a) Degree
b) Cardinality
c) Domain
d) Schema

Q17. Which combination correctly matches relational terms?
a) Row–Attribute, Column–Tuple
b) Row–Tuple, Column–Attribute
c) Table–Tuple, Row–Relation
d) Column–Relation, Table–Domain

Q18. A relation may have:
a) Only one candidate key
b) More than one candidate key
c) No candidate key under any condition
d) Only foreign keys

Q19. One candidate key selected to identify tuples in a relation is the:
a) Foreign key
b) Primary key
c) Superkey only
d) Domain key

Q20. In the PERSON relation containing unique Aadhar_number, PAN and Voter_ID, these three attributes can individually be:
a) Foreign keys only
b) Candidate keys
c) Domains
d) Tuples

Q21. In a database, the Dept_No column in the Teacher table refers to the Dept_ID column in the Department table. What is Dept_No in the Teacher table?
a) Candidate key
b) Foreign key
c) Primary key of Department
d) Superkey of both tables

Q22. DDL is mainly concerned with:
a) Defining data structure and constraints
b) Retrieving records only
c) Printing reports
d) Updating only salaries

Q23. DML includes operations to:
a) Insert, modify and delete data
b) Define only data types
c) Create only databases
d) Install MySQL

Q24. The SQL command used to create a table is:
a) MAKE TABLE
b) CREATE TABLE
c) NEW TABLE
d) BUILD TABLE

Q25. CHAR(n) represents a:
a) Variable-length character string
b) Fixed-length character string
c) Date
d) Decimal value

Q26. VARCHAR(n) represents a:
a) Fixed-length numeric value
b) Variable-length character string
c) Date
d) Boolean value

Q27. The data type suitable for storing a date in the chapter’s SQL examples is:
a) DATE
b) CHAR
c) INTEGER
d) VARCHAR only

Q28. DECIMAL(5,2) can store a value such as:
a) 999.99
b) 99999.99
c) 999999
d) 99.999

Q29. Which data type is appropriate for Teacher_ID in the given example?
a) DATE
b) INTEGER
c) CHAR(1)
d) DECIMAL(10,2)

Q30. To display the databases currently available on the server, use:
a) SHOW DATABASES
b) DISPLAY DATABASES
c) LIST DATABASE
d) VIEW DATABASE

Q31. To remove a database, the chapter uses:
a) DELETE DATABASE
b) DROP DATABASE
c) REMOVE DATABASE
d) CLEAR DATABASE

Q32. Before creating tables in a particular database, the database can be selected using:
a) OPEN
b) USE
c) SELECT DATABASE
d) CHOOSE

Q33. SHOW TABLES displays:
a) All databases
b) Tables in the current database
c) All columns in every database
d) All users

Q34. The command used to view the structure and description of a table is:
a) STRUCTURE
b) DESC
c) VIEW
d) DISPLAY

Q35. If First_Name must always contain a value, the most appropriate constraint is:
a) DEFAULT
b) NOT NULL
c) CHECK
d) CASCADE

Q36. A composite primary key contains:
a) More than one attribute
b) Only one tuple
c) Only foreign keys
d) No attributes

Q37. By default, a primary key is:
a) NULL
b) NOT NULL
c) DEFAULT NULL
d) Duplicate

Q38. DROP TABLE Teacher; is used to:
a) Remove a row
b) Remove the Teacher table
c) Remove one column
d) Remove a database

Q39. ALTER TABLE Teacher ADD Age INTEGER; will:
a) Add a row
b) Add an Age column
c) Change the table name
d) Delete Age

Q40. The command used to insert a tuple is:
a) ADD
b) INSERT
c) APPEND TABLE
d) PUT

Q41. The SQL command used to modify existing tuple values is:
a) UPDATE
b) MODIFY TABLE
c) CHANGE ROW
d) ALTER DATA

Q42. The main purpose of the WHERE clause in an UPDATE statement is to:
a) Select the rows to be modified
b) Create a table
c) Sort the result
d) Rename a column

Q43. Consider DELETE FROM Teacher;. Without a WHERE clause, it will:
a) Delete the table
b) Delete all tuples
c) Delete only the first tuple
d) Delete only NULL values

Q44. The command used to retrieve information from a database is:
a) GET
b) SELECT
c) FETCH TABLE
d) READ

Q45. In SELECT * FROM Teacher WHERE Teacher_ID=101;, the asterisk ‘*’ means:
a) Primary key
b) All attributes
c) All databases
d) All conditions

Q46. To avoid repeated department numbers in a query result, use:
a) UNIQUE
b) DISTINCT
c) DIFFERENT
d) SINGLE

Q47. A report needs teachers whose last name has not been specified. Which condition should be used?
a) Last_Name = NULL
b) Last_Name IS NULL
c) Last_Name == NULL
d) Last_Name LIKE NULL

Q48. A school wants the total salary paid to all teachers. Which aggregate function is appropriate?
a) COUNT
b) SUM
c) MAX
d) AVG

Q49. The highest teacher salary is required. The appropriate function is:
a) MIN
b) MAX
c) SUM
d) COUNT

Q50. A school wants the number of teachers in each department. The query needs:
a) ORDER BY only
b) GROUP BY with COUNT
c) DISTINCT only
d) LIKE with COUNT

Q51. Consider Statements I and II. Choose: Statement I: Data redundancy means repeated storage of the same information. Statement II: Data inconsistency occurs when similar copies are not updated consistently.
a) Both Statement I and II are TRUE
b) Both Statement I and II are FALSE
c) Statement I is TRUE and Statement II is FALSE
d) Statement I is FALSE and Statement II is TRUE

Q52. Statement I: ORDER BY sorts query results. Statement II: DESC specifies descending order.
a) Both Statement I and II are TRUE
b) Both Statement I and II are FALSE
c) Statement I is TRUE and Statement II is FALSE
d) Statement I is FALSE and Statement II is TRUE

Q53. A school database needs to find all student names that start with the letter “A”. Which SQL operator should be used for pattern matching?
a) BETWEEN
b) LIKE
c) EXISTS
d) DISTINCT

Q54. A database administrator wants to add a new column called Email to an existing Student table. Which SQL command should be used to modify the structure of the table?
a) ALTER TABLE
b) MODIFY TABLE
c) CHANGE TABLE
d) UPDATE TABLE

Q55. Which of the following SQL commands is not a Data Definition Language (DDL) command?
a) CREATE
b) ALTER
c) RENAME
d) UPDATE

Q56. A database contains a table named Employee with columns Emp_Name and Salary. Which SQL statement correctly retrieves these two columns?
a) SELECT Emp_Name AND Salary FROM Employee
b) SELECT Emp_Name, Salary FROM Employee
c) SELECT Emp_Name, Salary WHERE Employee
d) SELECT Emp_Name + Salary FROM Employee

Q57. In the SQL query SELECT Name FROM Students;, what is the purpose of the FROM clause?
a) It specifies the table from which the data is retrieved.
b) It specifies the condition for selecting records.
c) It sorts the retrieved records.
d) It groups the retrieved records.

Q58. A teacher wants to display the names and roll numbers of students stored in a database without deleting or modifying any data. Which SQL command should be used?
a) DELETE
b) INSERT
c) SELECT
d) UPDATE

Q59. Which of the following is an example of an SQL aggregate function?
a) UPPER()
b) AVG()
c) LEFT()
d) ROUND()

Q60. A school database administrator uses SQL commands to add, modify, and delete records in a table. These operations are part of DML. What does DML stand for?
a) Data Management Level
b) Data Model Language
c) Database Manipulation Link
d) Data Manipulation Language

Q61. A school wants to display only those students whose marks are greater than 80. Which clause should be used in the SELECT query to specify this condition?
a) WHERE
b) FROM
c) HAVING
d) LIKE

Q62. A database designer uses commands such as CREATE, ALTER, and DROP to define the structure of database objects. These commands belong to which category?
a) Dynamic Data Language
b) Detailed Data Language
c) Data Definition Language
d) Data Derivation Language

Q63. Consider the following SQL statement: SELECT * FROM Library; What type of SQL command is this?
a) DML
b) DDL
c) DCL
d) Integrity Constraint

Q64. A teacher wants to calculate the total marks, average marks, and number of students. Which of the following functions is not an aggregate function?
a) ROUND()
b) SUM()
c) COUNT()
d) AVG()

Q65. Consider a table named Weather containing the columns City and Temperature. Which SQL query will display the city names and temperatures in increasing order of temperature?
a) SELECT City FROM Weather ORDER BY Temperature;
b) SELECT City, Temperature FROM Weather;
c) SELECT City, Temperature FROM Weather ORDER BY Temperature;
d) SELECT City, Temperature FROM Weather ORDER BY City;

Q66. A school wants to select a field that can uniquely identify every student in its database. Which of the following would be the most suitable choice for a primary key?
a) Student Name
b) City
c) Roll Number
d) Subject

Q67. Consider the following table: Employee (Emp_ID, Name, Department, Salary). Which attribute would be the most appropriate choice for the primary key?
a) Name
b) Department
c) Salary
d) Emp_ID

Q68. Consider a table named Customers with a column FirstName. Which SQL query will display all customers whose first name ends with the letter “n”?
a) SELECT * FROM Customers WHERE FirstName = ‘n’;
b) SELECT * FROM Customers WHERE FirstName LIKE ‘n%’;
c) SELECT * FROM Customers WHERE FirstName LIKE ‘%n’;
d) SELECT * FROM Customers WHERE FirstName = ‘%n%’;

Q69. Consider the following query: SELECT Department, COUNT(*) FROM Employee GROUP BY Department; Which clause is used here to create separate groups before applying the aggregate function COUNT()?
a) GROUP BY
b) SELECT
c) WHERE
d) ORDER BY

Q70. A school administrator wants to find the total number of records in a table named Students. Which SQL function will count all rows?
a) COUNT()
b) NUMBER()
c) SUM()
d) TOTAL()

Q71. A table named Students contains a column called Project. Some students have submitted their projects while others have not. Which SQL query will count only the students whose Project value is not NULL?
a) SELECT COUNT(Project) FROM Students;
b) SELECT COLUMNS(Project) FROM Students;
c) SELECT COUNT(*) FROM Students;
d) SELECT NUMBER(Project) FROM Students;