Nexdigm Interview Questions and Answers

Answering questions on constraints and SQL queries for Programmer Analyst position

• Constraints are rules that limit the values that can be inserted into a database table

• Examples of constraints include primary key, foreign key, unique, check, and not null constraints

• Basic SQL queries include select, insert, update, and delete statements

• College project questions may vary depending on the project and interviewer

Public, private and protected are access modifiers used in object-oriented programming to control the visibility of class members.

• Public members can be accessed from anywhere in the program.

• Private members can only be accessed within the class they are declared in.

• Protected members can be accessed within the class they are declared in and any subclasses.

• Access modifiers help to enforce encapsulation and prevent unauthorized access to class members.

• For example, if a class has ...read more

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. Subquery is a query nested within another query. Performance optimization involves improving the efficiency of a system.

• Normalization involves breaking down data into smaller, manageable parts to avoid redundancy. For example, a database table can be split into multiple tables to store related data separately.

• A subquery is a query nested within another query. It is u...read more

SQL joins are used to combine data from two or more tables based on a related column.

• INNER JOIN returns only the matching rows from both tables

• LEFT JOIN returns all rows from the left table and matching rows from the right table

• RIGHT JOIN returns all rows from the right table and matching rows from the left table

• FULL OUTER JOIN returns all rows from both tables, with NULL values in the columns where there is no match

• CROSS JOIN returns the Cartesian product of both tables

Normalisation is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Organizes data into tables to minimize redundancy

• Ensures data dependencies make sense

• Reduces data anomalies

• Example: Splitting customer information into separate tables for name, address, and contact details

Oops concepts in Java refer to Object-Oriented Programming principles like Inheritance, Polymorphism, Encapsulation, and Abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Ability of an object to take on multiple forms.

• Encapsulation: Bundling of data with methods that operate on that data.

• Abstraction: Hiding the implementation details and showing only the necessary features of an object.