During the online interview, the interviewer delved into various object-oriented programming (OOP) concepts, seeking to gauge my understanding of the pillars of OOP, such as encapsulation, inheritance, polymorphism, and abstraction. They were particularly interested in my grasp of function overloading and function overriding. Function overloading refers to the ability to have multiple functions with the same name but different parameters, allowing for more flexibility and versatility in programming. On the other hand, function overriding occurs when a derived class defines a function with the same name and signature as a function in its base class, enabling the derived class to provide its own implementation. Additionally, the interviewer explored the topic of inheritance, which is a fundamental OOP principle that allows classes to inherit properties and behaviors from other classes. It enables code reuse, enhances modularity, and establishes a hierarchical relationship among classes. Inheritance facilitates the creation of specialized classes (derived classes) that inherit characteristics from a more general class (base class). In the realm of SQL queries, the interviewer tested my knowledge by presenting a real-life scenario: finding the second highest salary of employees in a database table. This question aimed to assess my ability to construct SQL queries to extract specific information from a relational database. To solve this particular challenge, I would utilize the "ORDER BY" clause combined with the "LIMIT" clause, ordering the salaries in descending order and limiting the result set to the second row. Overall, the interview encompassed a thorough exploration of OOP concepts, such as function overloading, function overriding, and inheritance, while also probing my SQL query skills with a practical scenario involving the retrieval of the second highest salary from an employee database.