Computer Science: CUET Mock Test - 3 - CUET MCQ

• Assertion is correct because Database Management System (DBMS) provides a variety of software tools for organising, processing and querying data in a flexible manner. MS Access, Oracle, SQL Server, and IBM-DB2 are examples of DBMS software.
• Reason is correct because normalisation is the process for removing data redundancy. It breaks up the information into separate but related tables.
• Therefore, assertion and reason both are correct, but reason is not the correct explanation of assertion.

The correct answer is Option 1

Select * from Customer

Where Gender = "M" and Membership >10;

Key Points

SELECT * FROM Customer WHERE Gender = 'M' AND Membership > 10;

• SELECT *: This retrieves all columns from the Customer table. You can replace * with specific column names if you only need certain details.
• FROM Customer: This specifies the table from which data will be retrieved.
• WHERE Gender = 'M': This filters the results to include only customers whose Gender is 'M' (male).
• AND Membership > 10: This further filters the results to include only male customers whose Membership value is greater than 10 months.
• This query effectively combines the conditions for male gender and membership duration to provide the desired output.

The correct answer is Option 3

Select TId, count(*) from Customer

group by TId;

Key PointsTo display the total number of customers under each trainer in the Gym accurately, we need to join the Trainer table with the Customer table and then group by the trainer's ID or name. Since the options provided don’t exactly reflect this approach and seem to focus on concepts rather than precise syntax, according to the options based on standard SQL practices and the requirement:

1. This option tries to select columns from the Customer table and attempts to reference the Trainer table, but it lacks a JOIN clause, making the WHERE condition syntactically incorrect.
2. This option selects the trainer name (TName) and counts the number of entries (customers) grouped by TId. However, "TName" is not available in the Customer table, implying this query would not execute as intended.
3. This option correctly counts the number of customers and groups them by TId, which is a simple and direct approach to understanding how many customers each trainer has. However, it lacks the JOIN with the Trainer table and does not display the trainer's name, which might be desired for clarity.
4. Similar to the first option, it attempts to apply a condition joining Trainer and Customer tables but lacks a JOIN clause, making the syntax incorrect.

Given the options and assuming the context where we don't directly join tables (since none of the options correctly implement a JOIN operation), the correct option based on SQL standards and the goal to "display total customers under each trainer" without considering the join explicitly would be:

Select TId, count(*) from Customer
group by TId;

This option correctly groups customers by their trainer IDs, allowing us to see how many customers each trainer has.

The correct answer is Option 2

Select TName, Dt_Appoint from Trainer
Where Activity = "Core"
Order by Dt_Appoint desc;

Key PointsThe correct SQL syntax for filtering the records before sorting them is to use the WHERE clause before the ORDER BY clause. Therefore, the query that correctly applies this structure to display the names of all trainers (trainees in the question seems to be a typo since the details pertain to trainers) with their date of appointment in descending order, who are taking core activity, would need to follow this logic.

Among the options given, the correct choice would be the one that places the WHERE clause directly after specifying the table, and before the ORDER BY clause, with the correct syntax for ordering the results in descending order:

Select TName, Dt_Appoint from Trainer Where
Activity = "Core"
Order by Dt_Appoint desc;

The correct answer is Option 1

Update Customer
Set Membership = 12
Where TId = "G101" or TId = "G102";

Key PointsThe correct SQL query to update the membership of all customers, under trainers with code G101 and G102, to 12 months is the one that uses the UPDATE statement to modify the value of the Membership field for all customers that meet the specified condition (their trainer ID being G101 or G102).

• The SET clause is used to specify the new value for the field you want to update.
• The WHERE clause is used to filter the records you want to update.
• When checking for multiple conditions, OR is used to update records that meet either one of the conditions.

Among the options given:
Update Customer
Set Membership = 12
Where TId = "G101" or TId = "G102";

This option correctly:

• Uses the UPDATE statement to indicate that you're going to change some rows in the Customer table.
• Uses Set Membership = 12 to set the Membership field to 12 months for all rows that match the condition.
• Uses the WHERE clause with an OR operator to specify that the condition matches customers whose TId is either "G101" or "G102".

So, the correct answer is:

Update Customer
Set Membership = 12
Where TId = "G101" or TId = "G102";

The correct answer is A, B and E only

Key Points

• Proper joining condition between the Trainer and Customer tables (either implicitly through the WHERE clause or using explicit JOIN syntax which isn't shown here).
• Correct filtering of Trainer salaries within the range of 20000 to 25000.
• Correct aliasing and referencing of column names, especially for the JOIN condition and selected columns.
• Select TName, Salary, Cust_Name, Fee: This selects the desired columns from both tables: TName and Salary from Trainer and Cust_Name (assuming a typo and it should be Cust_Name) and Fee from Customer.
• From Customer, Trainer: This specifies the tables involved in the join.
• Where C.TId = T.TId: This establishes the join condition between the Customer and Trainer tables, ensuring we retrieve data for trainers with matching IDs in both tables.
• and Salary between 20000 and 25000: This filters the results to include only trainers whose salaries fall within the specified range (20000 to 25000).

Options A, B, and E all construct the correct SQL query to display the desired report with proper table joins, column selection, and filtering based on trainer salary.

The correct answer is Full outer join

Key PointsA "Full Outer Join" (also known as Full Join) is used in SQL to combine rows from two or more tables based on a related column. The outcome of a Full Outer Join includes all the records from both the left and the right tables, and it matches rows from both tables where the join condition is met. If there isn't a match, the result is NULL on either the left or the right side (or both, in case of no common relation).

So the correct answer is Full outer join

Additional Information

• A NATURAL JOIN is a type of join operation in SQL that is used to combine rows from two or more tables based on the columns they have in common. This can be particularly useful when you have two tables that contain related data, but do not have an explicitly defined foreign key relationship.
• Unlike other join types, NATURAL JOIN doesn't require a specific condition to match columns from one table with another, as it automatically matches columns with the same name in both tables. For example, if both tables have a column named 'customer_id', the NATURAL JOIN will use this column as the join condition.
• 

The correct answer is 16

Key PointsIn the context of relational databases and SQL, a Cartesian product (or CROSS JOIN) refers to a JOIN operation that returns the combination of every row of the first table with every row of the second table.
If table1 has n rows and table2 has m rows, the Cartesian product of these two tables will result in a table with n*m rows.
If table1 has 4 rows and table2 has 4 rows, the Cartesian product of these two tables will result in a table with 4*4 = 16 rows.
So the correct answer is 16

The correct answer is 4

Key PointsA "Left Outer Join" is another type of JOIN operation in SQL, which is used to combine rows from two or more tables based on a related column between them.

Unlike the Right Outer Join, the Left Outer Join returns all the records from the left table, and the matched records from the right table. If there is no match found in the right table, the result is NULL on the right-side part.

Here the above table is left outer join they have contain four row so correct answer is 4.

The correct answer is 4

Key Points A "Right Outer Join" is a concept from SQL (Structured Query Language), used in relational databases. It's a method of combining two tables based on a common column between them, showing all records from the 'right' table and matched records from the 'left' table.

The result of a right outer join contains all the records from the right table and any records in the left table that match the join condition. For the records in the right table that do not have a corresponding match in the left table, the result is NULL in the columns of the left table.

Here the above table is right outer join they have contain four row so correct answer is 4.

The correct answer is Option 2

Key PointsA "Right Outer Join" is a concept from SQL (Structured Query Language), used in relational databases. It's a method of combining two tables based on a common column between them, showing all records from the 'right' table and matched records from the 'left' table.

The result of a right outer join contains all the records from the right table and any records in the left table that match the join condition. For the records in the right table that do not have a corresponding match in the left table, the result is NULL in the columns of the left table.

When we are allocating the memory using new operator and allocation fail, then bad_alloc exception is thrown by the program.

A file management system can typically access records from only one file at a time.

Both the Assertion and Reason are true, and the Reason is the correct explanation of the Assertion. Data is any form of information that can be processed by a computer, including text, numbers, images, audio, and video.

Top 10 most popular RDBMSs are:
Oracle
MySQL
SQL Server
PostgreSQL
IBM DB2
Microsoft Access
SQLite
MariaDB
Informix
Azure SQL
So, all the above is correct.

The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys must contain UNIQUE values, and cannot contain NULL values.

'Try' is used to define the code block where an exception might occur. 'Raise' is used to trigger a specific exception intentionally. 'Finally' defines the code block that will execute regardless of whether an exception occurs. 'Except' is used to handle the raised exception.

We can do all the above using computer networks.

The 'x' file access mode is used to open a file for exclusive creation. This mode allows you to create a new file but will raise an error if the file already exists. This mode is useful when you want to create a new file and ensure that it does not already exist. The 'a' file access mode is used to open a file for appending data to the end of the file. This mode allows you to write to the file but not overwrite any existing content. If the file does not exist, it will be created.

When stack is completely full (i.e. TOP= MaxSize -1) and we try to insert more elements onto stack then this condition is called overflow condition and no further element could be inserted now until any element is deleted.

Both the stack and queue are the linear data structure, which means that the elements are stored sequentially and accessed in a single run.

The major limitation of binary search is that there is a need for the sorted array to perform the binary search operation. If the array is not sorted the output is either not correct or maybe after a long number of steps and according to the data structure, the output should come in a minimum number of steps.
Not a limitation of Binary search :Binary search algorithm is not efficient when the data elements are more than 1000.

Both the Assertion and Reason are true, and the Reason is the correct explanation of the Assertion. Data visualization is the process of creating visual representations of data to communicate information effectively. It helps to uncover patterns, trends, and insights in data that might not be apparent in raw data, making it easier for decision-makers to understand and act on the data.

Data processing refers to the process of performing specific operations on a set of data or a database.
Process data is called information.

The Assertion is not correct and Reason are correct. A LAN (Local Area Network) is a computer network that connects devices within a small geographic area such as a building or a campus not city. LANs typically use wired or wireless connections to enable devices to communicate with each other and share resources such as printers and files.

The append() method in Python adds a single item to the existing list.

The del keyword is used to delete objects. In Python, everything is an object. So, the del keyword can also be used to delete variables, lists, or parts of a list, etc.

The len() function returns the number of items (length) in an object.

The isEmpty() method checks whether a string is empty or not. This method returns true if the string is empty (length() is 0), and false if not.

The isEmpty() method checks whether a string is empty or not.