Question 1

Question 5Assertion (A): Each table must have one primary key.Reasoning (R): Primary key is a set of one or more attributes that uniquely identifies a tuple in a relation.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.ExplanationIn a database, each table can have only one primary key, which is unique and non-redundant in nature. The primary key is a set of one or more attributes or fields that uniquely identify a tuple or row in a relation.

Question 2

Question 6Assertion (A): A database can have only one table.Reasoning (R): If a piece of data is stored in two places in a database, then it leads to wastage of storage space.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is false but R is true.ExplanationA database can have multiple tables. Data redundancy, which occurs when the same data is repeated in multiple places within a database, leads to wastage of storage space. A DBMS eliminates data redundancy by integrating files, ensuring that multiple copies of the same data are not stored.

Question 3

Question 9Assertion (A): The SQL keyword Like is used with wildcards only.Reasoning (R): '_' underscore and "%" per cent are the two wildcard characters used with LIKE clause.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.ExplanationThe SQL LIKE keyword allows the use of wildcard characters to perform pattern matching. SQL provides two wildcard characters to use with the LIKE operator: the percent sign (%) which matches any string, and the underscore ("_") which matches any single character.

Question 4

Question 10Assertion (A): DISTINCT clause must be used in an SQL statement to eliminate duplicate rows.Reasoning (R): DISTINCT only works with numeric data type only.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is true but R is false.ExplanationThe DISTINCT clause is used to remove duplicate rows from the results of a SELECT statement. It retrieves only unique values for a column in the table. The DISTINCT keyword in SQL can be used with any data type.

Question 5

Question 11Assertion (A): FLOAT and DOUBLE are data types.Reasoning (R): Both can hold any number up to 23 digits.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is true but R is false.ExplanationFLOAT and DOUBLE are data types in SQL, used to store decimal numbers. FLOAT can store values with a precision of around 6-7 digits, while DOUBLE can store values with a precision of around 15-16 digits.

Question 6

Question 1Kunal has entered the following SQL command in the table 'STUDENT' that has TotalMarks as one of the columns:SELECT * FROM Student;                         #Statement-1The total number of rows displayed is 20.Then Kunal enters the following command:SELECT * FROM STUDENT WHERE TotalMarks < 100;  #Statement-2 The number of rows displayed is 15.Kunal then enters the following command:SELECT * FROM STUDENT WHERE TotalMarks >= 100; #Statement-3He predicts the output of the above query as 5. Do you agree with Kunal? Give reasons for your answer.

Accepted Answer

I disagree with Kunal's prediction. Since Statement-1 returns all the rows and columns of the table Student i.e., 20, and Statement-2 returns 15 rows with TotalMarks less than 100, it means 20 - 15 = 5 students have TotalMarks greater than 100. However, Statement-3 returns rows where TotalMarks is greater than or equal to 100, which includes students who scored exactly 100, and we don't know how many students scored exactly 100, so the number of rows returned by Statement-3 will be greater than or equal to 5, but not necessarily exactly 5.

Question 7

Question 2(a)Mr. Shivaya is using a table 'COURSE' with the following columns: COURSE_ID, COURSE_NAME. He needs to display the names of all the courses which end with "SCIENCE". He has written the query mentioned below, which is not giving the desired result.SELECT COURSE_ID, COURSE_NAME FROM COURSE WHERE COURSE_NAME = '_SCIENCE';Help Mr. Shivaya to write the correct query.

Accepted Answer

SELECT COURSE_ID, COURSE_NAME FROM COURSE WHERE COURSE_NAME LIKE '%SCIENCE';ExplanationThe "=" operator is used for exact matching and the "_" wildcard character in SQL is used to match a single character, not a sequence of characters. To achieve the desired result, Mr. Shivaya should use the LIKE operator with the "%" wildcard character, which matches any sequence of characters.

Question 8

Question 3Your school management has decided to organize cricket matches between students of Classes XI and XII. All the students are divided into four teams—Team Rockstars, Team BigGamers, Team Magnet and Team Current. During the summer vacations, various matches are to be held between these teams. Help your sports teacher do the following:(a) Create a database "Sports" and open it for creating table.(b) Create a table "Team" with the following considerations:It should have a column TeamID for storing an integer value between 1 and 9, which refers to unique identification of a team.Each TeamID should have its associated name (TeamName), which should be a string of length not less than 10 characters.Give the statement to make TeamID the primary key.(c) Show the structure of the table Team using SQL command.(d) As per the preferences of the students, four teams were formed as given below.Insert these four rows in Team table:Row 1: (1, Team Rockstars)Row 2: (2, Team BigGamers)Row 3: (3, Team Magnet)Row 4: (4, Team Current)(e) Display the table Team.

Accepted Answer

Question 9

Question 12Which of the following are DDL commands?(A) Delete(B) Create(C) Update(D) Alter(E) Drop(B), (D) and (E)(A), (B) and (D)(B), (C) and (D)(A), (B) and (C)

Accepted Answer

(B), (D) and (E)Reason — DDL (Data Definition Language) commands are used to create and define tables and other database objects in SQL (Structured Query Language). DDL commands such as CREATE, ALTER, and DROP, are used to create, define, change and delete objects like tables, indexes, views, and constraints.

Question 10

Question 13Identify the correct statement(s):Statement 1 (S1): Char data type in MySQL stores fixed length strings.Statement 2 (S2): Char data type stores string smaller than the maximum field size.(S1) : Correct, (S2) : Correct(S1): Incorrect, (S2) : Correct(S1): Correct, (S2) : Incorrect(S1) : Incorrect, (S2) : Incorrect

Accepted Answer

(S1): Correct, (S2) : IncorrectReason — The CHAR data type provides fixed-length memory storage. It specifies a fixed-length character string. If the input string is shorter, MySQL pads it with spaces to fill the fixed length. If the input string is longer, it is truncated to fit the fixed length.

Question 11

Question 14Which of the following keywords is used to display non-repeated values in MySQL?UniqueAllOrder byDistinct

Accepted Answer

DistinctReason — The DISTINCT keyword is used to display the unique values of the column in MySQL.

Source: This question is from Review of Database Concepts & SQL, Informatics Practices &mdash; Class 12, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter Review of Database Concepts & SQL: Question, Keywords, Display, Non, Repeated, Values. These are fundamental topics in Informatics Practices that students are expected to master as part of the CBSE Class 12 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Informatics Practices papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach MCQsMultiple choice questions test your ability to quickly recall facts and apply concepts. Read all options carefully before selecting your answer. Use the process of elimination to rule out clearly incorrect options first. If two options seem similar, look for the subtle difference that makes one more accurate. For numerical MCQs, verify your answer by substituting it back into the problem.
Key Points to RememberRead the question carefully and identify all parts before answering.
Use the terminology specific to this subject and chapter.
Review the textbook content for this chapter before attempting questions.
Practice writing concise, well-structured answers within time limits.
Related Questions from Review of Database Concepts & SQLQ1: Question 1 Kunal has entered the following SQL command in the table &#x27;STUDENT&#x27; that has TotalMarks...
Q10: Question 10 Assertion (A): DISTINCT clause must be used in an SQL statement to eliminate duplicate...
Q11: Question 11 Assertion (A): FLOAT and DOUBLE are data types. Reasoning (R): Both can hold any number...
Q12: Question 12 Which of the following are DDL commands? (A) Delete (B) Create (C) Update (D) Alter (E)...
Q13: Question 13 Identify the correct statement(s): Statement 1 (S1): Char data type in MySQL stores...
Practice more questions from Review of Database Concepts & SQL &mdash; Informatics Practices, Class 12 CBSE

Question 12

Question 15The SQL statements always end with ............... .,:;"

Accepted Answer

;Reason — The SQL statements always ends with semicolon (;) to indicate the end of the statement.

Source: This question is from Review of Database Concepts & SQL, Informatics Practices &mdash; Class 12, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter Review of Database Concepts & SQL: Question, Sql, Statements, End, Review of Database Concepts & SQL, Informatics Practices. These are fundamental topics in Informatics Practices that students are expected to master as part of the CBSE Class 12 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Informatics Practices papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach MCQsMultiple choice questions test your ability to quickly recall facts and apply concepts. Read all options carefully before selecting your answer. Use the process of elimination to rule out clearly incorrect options first. If two options seem similar, look for the subtle difference that makes one more accurate. For numerical MCQs, verify your answer by substituting it back into the problem.
Key Points to RememberRead the question carefully and identify all parts before answering.
Use the terminology specific to this subject and chapter.
Review the textbook content for this chapter before attempting questions.
Practice writing concise, well-structured answers within time limits.
Related Questions from Review of Database Concepts & SQLQ1: Question 1 Kunal has entered the following SQL command in the table &#x27;STUDENT&#x27; that has TotalMarks...
Q10: Question 10 Assertion (A): DISTINCT clause must be used in an SQL statement to eliminate duplicate...
Q11: Question 11 Assertion (A): FLOAT and DOUBLE are data types. Reasoning (R): Both can hold any number...
Q12: Question 12 Which of the following are DDL commands? (A) Delete (B) Create (C) Update (D) Alter (E)...
Q13: Question 13 Identify the correct statement(s): Statement 1 (S1): Char data type in MySQL stores...
Practice more questions from Review of Database Concepts & SQL &mdash; Informatics Practices, Class 12 CBSE

Question 13

Question 18Rajveer wants to rename column in display result for his query. Select the appropriate query for the same:Select Ename, Salary*12 Annual Salary From Emp;Select Ename, Salary*12 Rename "Annual Salary" From Emp;Select Ename, Salary*12 Change "Annual Salary" From Emp;Select Ename, Salary*12 as "Annual Salary" From Emp;

Accepted Answer

Select Ename, Salary*12 as "Annual Salary" From Emp;Reason — The AS keyword is used to give an alias to a column or expression in the SELECT statement. In this case, AS "Annual Salary" is used to rename the column Salary*12 to "Annual Salary" in the display result.

Question 14

Question 19The symbol Asterisk (*) in a select query retrieves ............... .All data from the tableData of primary key onlyNULL dataNone of these

Accepted Answer

All data from the tableReason — The asterisk symbol (*) is a wildcard character in SQL that retrieves all columns or fields from a table. When used in a SELECT statement, it returns all columns and rows from the specified table.

Question 15

Question 20Consider the attributes ( RollNumber, SName, SDateofBirth, GUID ) of the table Student. According to you, which of the following options is the correct representation of the table after executing the following query?Insert Into Student (RollNumber, SName, SDateofBirth) 
Values(2, 'Sudha', '2002-02-28') ;
1.RollNumberSNameSDateofBirthGUID1Atharv2003-05-15123548992Sudha2002-02-28NULL2.RollNumberSNameSDateofBirthGUID1Atharv2003-05-15123548992Sudha2002-02-28000000003.RollNumberSNameSDateofBirthGUID1Atharv2003-05-15123548992Sudha2002-02-2804.RollNumberSNameSDateofBirthGUID1Atharv2003-05-15123548992Sudha2002-02-28

Accepted Answer

RollNumberSNameSDateofBirthGUID1Atharv2003-05-15123548992Sudha2002-02-28NULLReason — In the above code, a new row is inserted into the 'Student' table, values are provided for RollNumber, SName, and SDateofBirth, but not for GUID. Since GUID is not specified, it will take on its default value, which may be NULL if no default value is defined for the column.

Question 16

Question 3What is the difference between data and information?

Accepted Answer

DataInformationData refers to raw facts, figures, or values that are collected and stored without any specific context or interpretation. It is unprocessed and lacks meaning on its own.Information is processed, organized, and meaningful data that has been analyzed, interpreted, and structured to provide context, relevance, and value. It is derived from data through analysis and is used to make decisions or gain insights.Data is unstructured, discrete.Information is structured, organized.

Question 17

Question 7(i)Explain the difference between database and file.

Accepted Answer

DatabaseFileDatabase is an organized collection of interpreted data that serves many applications.A file is a collection of unorganized data stored in a single location.Data retrieval is fast and efficient, as databases use indexing and querying mechanisms.Data retrieval is slow and inefficient, as the entire file needs to be searched.Data sharing is easy, as multiple users and applications can access the database simultaneously.Data sharing is limited, as files are typically accessed by a single user or application.Data integrity is ensured through constraints, triggers, and transactions.Data integrity is not ensured, as data can be corrupted or lost easily.Databases support relationships between data entities.Files do not support relationships between data entities.

Question 18

Question 7(ii)Explain the difference between data and file.

Accepted Answer

DataFileData refers to raw facts, figures, or values that are collected and stored without any specific context or interpretation.A file is a collection of unorganized data stored in a single location.The purpose of data is to convey information, provide insights, or support decision-making.The purpose of a file is to store, manage, and provide access to the data.Data can exist in various formats, such as numbers, text, images, or audio, and can be structured or unstructured.A file has a specific format and structure, defined by its file type (e.g., .txt, .jpg, .mp3), which determines how the data is stored and retrieved.

Question 19

Question 10Summarize the major differences between a relation and a traditional file.

Accepted Answer

Relation fileTraditional fileData organized in tables with rows and columns.Data stored in unstructured formats.Supports structured querying with SQL.Lacks standardized querying abilities.Allows for defining relationships between tables.No inherent support for relationships.Offers flexibility in data storage and retrieval.Limited flexibility in data organisation.Examples : MySQL, PostgreSQLExamples : Text files, CSV files, Excel spreadsheets

Question 20

Question 11What is the relationship between a database and a table?

Accepted Answer

A database is an organized collection of interrelated data that serves many applications, while a table is a collection of logically related records. In other words, it is a named collection of data items that represent a complete unit of information within a database.

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