OMFYS Technologies Interview Questions, Process, and Tips

Oops concept in C# refers to Object-Oriented Programming principles like inheritance, encapsulation, polymorphism, and abstraction.

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

• Encapsulation hides the internal state of an object and only exposes necessary information.

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

• Abstraction focuses on...read more

A filter is a tool used to select specific data from a larger set based on certain criteria.

• Filters can be used in various programming languages and databases to narrow down results.

• Types of filters include text filters, numeric filters, date filters, and custom filters.

• Examples of filters include WHERE clause in SQL, filter() function in Python, and filter() method in JavaScript.

A view in SQL Server is a virtual table that contains the result set of a SELECT statement.

• Views are used to simplify complex queries by storing them as a virtual table.

• Views can be used to restrict access to specific columns or rows of a table.

• Views can be created using the CREATE VIEW statement.

• Example: CREATE VIEW vwEmployee AS SELECT FirstName, LastName FROM Employees;

Primary key uniquely identifies a record in a table, while unique key ensures uniqueness but allows null values.

• Primary key enforces uniqueness and not null constraint on a column

• Primary key can consist of multiple columns

• Unique key enforces uniqueness but allows null values

• Unique key can be applied to multiple columns as well

Procedures are a set of instructions that perform a specific task, while functions return a value after performing a task.

• Procedures do not return a value, while functions do.

• Functions can be called within expressions, while procedures cannot.

• Functions are more versatile and reusable compared to procedures.

A trigger in SQL Server is a special type of stored procedure that automatically executes when certain events occur in a database.

• Triggers can be used to enforce business rules, audit changes, or replicate data.

• There are two main types of triggers in SQL Server: DML triggers and DDL triggers.

• DML triggers fire in response to data manipulation language (DML) events like INSERT, UPDATE, and DELETE.

• DDL triggers fire in res...read more

Interface in C# is a reference type that defines a contract for classes to implement certain methods and properties.

• Interfaces cannot have implementation, only method signatures and properties.

• Classes can implement multiple interfaces in C#.

• Interfaces are used to achieve abstraction and multiple inheritance in C#.

• Example: public interface IShape { void Draw(); }

• Example: public class Circle : IShape { public void Draw()

Abstract class is a class that can have both abstract and non-abstract methods, while interface is a contract that defines methods that must be implemented by a class.

• Abstract class can have constructor, fields, and methods, while interface cannot have any implementation.

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

• Abstract classes are used when some common functionality needs ...read more

Partial view in ASP.NET MVC allows reusing common UI elements across multiple views.

• Partial views are like reusable components that can be included in multiple views

• They help in reducing code duplication and improving maintainability

• Partial views are rendered using Html.Partial or Html.RenderPartial methods

Method overloading is having multiple methods in the same class with the same name but different parameters. Method overriding is redefining a method in a subclass with the same name and parameters as in the superclass.

• Method overloading involves multiple methods with the same name but different parameters.

• Method overriding involves redefining a method in a subclass with the same name and parameters as in the superclas...read more

Union combines and removes duplicates, while union all combines all rows including duplicates.

• Union removes duplicates, while union all includes duplicates.

• Union is slower as it has to remove duplicates, while union all is faster.

• Use union when you want to remove duplicates, use union all when duplicates are acceptable.

Foreign key in SQL is a field in a table that links to a primary key in another table, enforcing referential integrity.

• Foreign key constraints ensure data consistency between related tables

• Foreign key values must exist in the referenced table's primary key column

• Foreign key can be used to establish relationships between tables

Constructor in C# is a special type of method that is automatically called when an instance of a class is created.

• Constructors have the same name as the class and do not have a return type.

• They can be used to initialize the data members of the class.

• Constructors can be overloaded to have multiple versions with different parameters.

• Example: public class Person { public Person(string name) { this.Name = name; } }