40+ Wipro PARI Interview Questions and Answers

DBMS stands for Database Management System. It is a software that manages databases and allows users to interact with them.

• DBMS is a software system that allows users to create, retrieve, update, and manage data in a database.

• There are different types of DBMS, such as relational DBMS (RDBMS), object-oriented DBMS (OODBMS), and NoSQL DBMS.

• Examples of popular DBMS include MySQL, Oracle Database, Microsoft SQL Server, and MongoDB.

Use SQL query with COUNT function to get the count of records in the table.

• Use the SQL query: SELECT COUNT(*) FROM table_name;

• Replace 'table_name' with the actual name of the table you want to count records from.

• The COUNT function returns the number of rows that match the specified criteria.

To add a record to a table, you can use SQL INSERT statement.

• Use the INSERT INTO statement followed by the table name

• Specify the column names and values to be inserted

• Example: INSERT INTO employees (id, name, salary) VALUES (1, 'John Doe', 50000)

Joins in SQL are used to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column.

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column;

To update a table, use SQL UPDATE statement with specified column values and conditions.

• Use SQL UPDATE statement to specify the table name and set the new values for columns

• Add a WHERE clause to specify the conditions for which rows to update

• Example: UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;

Encryption and encoding are both methods of transforming data, but encryption is more secure and reversible.

• Encryption is the process of converting data into a secret code to protect its confidentiality, integrity, and authenticity.

• Encoding is the process of converting data into a different format for transmission or storage purposes.

• Encryption uses a key to scramble the data, while encoding does not.

• Examples of encryption include AES, RSA, and Blowfish.

• Examples of encoding i...read more

Truncate is a DDL operation that removes all rows from a table, while delete is a DML operation that removes specific rows.

• Truncate is faster than delete as it doesn't generate any undo logs or triggers.

• Truncate cannot be rolled back, while delete can be rolled back using the transaction log.

• Truncate resets the identity of the table, while delete doesn't.

• Truncate doesn't fire delete triggers, while delete does.

• Truncate is non-logged operation, while delete is logged operation...read more

Constraints and DDL commands are essential for defining and managing database structures.

• Constraints ensure data integrity and consistency.

• DDL commands are used to create, modify, and delete database objects.

• Examples of constraints include primary keys, foreign keys, and check constraints.

• Examples of DDL commands include CREATE TABLE, ALTER TABLE, and DROP TABLE.

No, controller and service annotations serve different purposes in a software application.

• Controller annotations are used to define the entry points for incoming requests and map them to specific methods in a controller class.

• Service annotations are used to mark a class as a service component that can be injected into other classes for business logic implementation.

• Mixing up controller and service annotations can lead to confusion in the application structure and functionalit...read more

Synchronized ensures only one thread can access a resource at a time, while concurrent allows multiple threads to access it simultaneously.

• Synchronized is used for thread safety and mutual exclusion.

• Concurrent is used for improving performance and scalability.

• Synchronized can cause performance issues due to locking.

• Concurrent can cause race conditions and requires careful synchronization.

• Examples of synchronized: synchronized methods, synchronized blocks.

• Examples of concurren...read more

XSS and SQLi are common web application vulnerabilities. XSS allows attackers to inject malicious scripts, while SQLi allows them to manipulate database queries.

• XSS (Cross-Site Scripting) is a vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users.

• There are three types of XSS: Stored XSS, Reflected XSS, and DOM-based XSS.

• Stored XSS occurs when the malicious script is permanently stored on the target server and served to users.

• Refl...read more

Black box testing involves testing an application without knowledge of its internal workings.

• Identify inputs and expected outputs

• Test for boundary conditions and error handling

• Use techniques like equivalence partitioning and decision tables

• Focus on user interface and user experience

• Use automated tools for efficiency

Heap memory is used for dynamic memory allocation, while stack memory is used for static memory allocation.

• Heap memory is allocated at runtime and can be accessed randomly, while stack memory is allocated at compile time and is accessed in a LIFO order.

• Heap memory is managed manually by the programmer, while stack memory is managed automatically by the system.

• Heap memory is larger in size compared to stack memory, but slower in access speed.

• Examples: Dynamic memory allocation...read more

Program for hashcode and equal implementation

• Override hashCode() method to generate unique hashcode for each object

• Override equals() method to compare two objects based on their attributes

• Ensure that if two objects are equal, their hashcodes should also be equal

• Use Objects.hash() method to generate hashcode for multiple attributes

• Example: public int hashCode() { return Objects.hash(attribute1, attribute2); }

• Example: public boolean equals(Object obj) { return this.attribute1 =...read more

Joins are used to combine data from two or more tables based on a related column between them.

• Types of joins include inner join, left join, right join, and full outer join.

• Inner join returns only the matching rows from both tables.

• Left join returns all the rows from the left table and matching rows from the right table.

• Right join returns all the rows from the right table and matching rows from the left table.

• Full outer join returns all the rows from both tables, with NULL val...read more

=== is a strict equality operator in JavaScript that checks if two values are equal in type and value.

• === compares two values without type conversion

• Returns true if both values are strictly equal, false otherwise

• Example: 5 === '5' returns false because they are of different types

Exception handling is a mechanism to handle runtime errors in a program to prevent crashes and ensure graceful error recovery.

• Allows for graceful handling of runtime errors

• Prevents program crashes

• Ensures proper error recovery

• Helps in debugging and maintaining code

• Examples: try-catch blocks in Java, catch blocks in C++

Immutable class is a class whose instances cannot be modified after creation.

• Instances of immutable class cannot be changed once created

• Immutable classes are often used for objects that should not be modified, like dates or strings

• Examples of immutable classes in Java are String, Integer, and LocalDate

Immutable class can be created by making all fields private and final, providing only getters and no setters.

• Make all fields private and final

• Provide only getters, no setters

• Avoid modifying state within the class

Controller is a general term for classes that handle incoming requests, while RestController is specifically for RESTful web services in Spring.

• Controller is a general term for classes that handle incoming requests in a web application.

• RestController is a specialized version of a controller that is used for creating RESTful web services in Spring framework.

• RestController is annotated with @RestController, which combines @Controller and @ResponseBody annotations.

• RestController...read more

Technical troubleshooting involves identifying, isolating, and resolving technical issues to ensure systems are functioning properly.

• Identify the problem by gathering information from the user or system logs

• Isolate the issue by testing different components or configurations

• Resolve the problem by applying solutions based on the root cause

• Document the troubleshooting process and solution for future reference

Cloud computing is the delivery of computing services over the internet, allowing users to access and store data and applications remotely.

• Cloud computing involves storing and accessing data and programs over the internet instead of on a computer's hard drive.

• It offers on-demand access to a shared pool of configurable computing resources, such as servers, storage, and applications.

• Users can access cloud services from anywhere with an internet connection, making it convenient ...read more

Classes can have both implementation and state, while interfaces only have method signatures.

• Classes can have constructors, interfaces cannot

• Classes can have fields, interfaces cannot

• A class can implement multiple interfaces, but can only inherit from one class

• Example: Class 'Car' can have fields like 'color' and 'model', while Interface 'Drivable' only has method signatures like 'start' and 'stop'

A singleton class is a class that can only have one instance created throughout the entire application.

• Singleton classes are often used for logging, driver objects, caching, thread pools, database connections, etc.

• They have a private constructor to prevent instantiation from other classes.

• They provide a global point of access to the instance.

Parameters of a call include duration, purpose, resolution, customer satisfaction, and adherence to company policies.

• Duration of the call should be within a specified range

• Purpose of the call should be to address customer inquiries or issues

• Resolution of the call should meet customer expectations

• Customer satisfaction should be measured through feedback or surveys

• Adherence to company policies and procedures during the call

eClinicalWorks is a leading provider of healthcare IT solutions, offering electronic health records (EHR) and practice management software.

• eClinicalWorks offers a comprehensive suite of healthcare IT solutions, including EHR, practice management, patient engagement, and revenue cycle management.

• Their EHR system allows healthcare providers to streamline workflows, improve patient care, and enhance clinical outcomes.

• eClinicalWorks has a strong focus on interoperability, allowin...read more

I will listen to the customer's concerns, empathize with their situation, apologize for any inconvenience, offer a solution or compensation, and ensure their issue is resolved.

• Listen actively to the customer's complaints without interrupting

• Empathize with the customer's emotions and show understanding

• Apologize sincerely for any inconvenience caused

• Offer a solution or compensation to resolve the issue

• Follow up with the customer to ensure their satisfaction

Immutable class is a class whose state cannot be modified after creation.

• Use final keyword to make class immutable

• Make all fields private and final

• Do not provide setter methods

• Return new instances when modifying state

JSP stands for JavaServer Pages, a technology used for creating dynamic web pages using Java.

• JSP allows embedding Java code in HTML pages

• It is compiled into servlets by the server before execution

• JSP simplifies the process of developing web applications by separating the presentation layer from the business logic

VPNs are Virtual Private Networks that allow users to securely access a private network over a public network.

• VPNs encrypt data to ensure privacy and security

• They can be used to access region-restricted websites or bypass censorship

• Common VPN protocols include OpenVPN, L2TP/IPsec, and IKEv2

Telnet is a network protocol used to access and manage devices remotely over a network.

• Telnet allows users to connect to a remote device or server using a command-line interface.

• It is commonly used for troubleshooting network issues, configuring devices, and accessing remote servers.

• Telnet operates on port 23 and transmits data in plain text, making it less secure compared to SSH.

• Example: telnet 192.168.1.1 23

Telnet is a network protocol used to connect to remote devices, ping is a network utility used to test connectivity, and SQL is a language used for managing databases.

• Telnet is a protocol that allows you to connect to a remote device over a network.

• Ping is a utility used to test the reachability of a host on an IP network.

• SQL (Structured Query Language) is a language used for managing and querying databases.

• Examples: Telnet can be used to connect to a remote server, ping can ...read more

Immutable class program in Java

• Use the 'final' keyword to make class immutable

• Make all fields private and final

• Do not provide setter methods, only getter methods

• Ensure deep copy of mutable objects in constructor or getter methods

A SQL join query combines rows from two or more tables based on a related column between them.

• Use keywords like INNER JOIN, LEFT JOIN, RIGHT JOIN, or FULL JOIN to specify the type of join

• Specify the columns to join on using ON keyword

• Include the table names and column names in the query

A left join query combines rows from two tables based on a related column, including all rows from the left table.

• Use the LEFT JOIN keyword in your query

• Specify the columns you want to select from both tables

• Specify the join condition using ON clause

• Example: SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id

HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• Hashmap uses hashing to store and retrieve values based on keys.

• It uses an array of buckets to store key-value pairs.

• The hash function maps the key to an index in the array.

• If multiple keys map to the same index, a linked list is used to store them.

• Basic operations like put, get, and remove have constant time complexity on average.

• Java's HashMap implementation al...read more

Java is a popular programming language known for its platform independence, object-oriented features, and robust libraries.

• Platform independence - Java programs can run on any platform that has a Java Virtual Machine (JVM)

• Object-oriented - Java supports the principles of encapsulation, inheritance, and polymorphism

• Robust libraries - Java has a vast collection of libraries for various tasks such as networking, database access, and GUI development

Abstract class is a class that cannot be instantiated and may contain abstract methods that must be implemented by subclasses.

• Cannot be instantiated directly

• May contain abstract methods

• Subclasses must implement abstract methods

• Used for defining common behavior for subclasses

Inheritance is a concept in object-oriented programming where a class inherits attributes and methods from another class.

• Allows a class to inherit attributes and methods from another class

• Promotes code reusability and reduces redundancy

• Creates a parent-child relationship between classes

• Derived class can access public and protected members of the base class

• Example: Class Car can inherit from class Vehicle to reuse common attributes like speed and color

The current drawing refers to the amount of money being withdrawn from an account.

• The current drawing can be found on the account statement or online banking portal.

• It is important to keep track of current drawings to avoid overdrawing the account.

• Examples of current drawings include ATM withdrawals, checks written, and electronic transfers.

Polymorphism is the ability of a function or method to behave differently based on the object it is acting upon.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• It enables a single interface to be used for different data types or objects.

• Examples include method overloading and method overriding in object-oriented programming.