Relationships in SQL Server

One-To-Many

• One DeviceClass can have many DeviceTypes
• Key symbol represent one, infinity symbol represent many
• Note: You don’t have to have many. 

Many-To-Many

• Not as common as One-To-Many
• Many-To-Many relationship is expressed with help of junction tables
• A table name with a joint name of two tables

One-To-One

• Least commonly used relationship
• One row in one tables is related to, One row in other table

Reference: https://www.youtube.com/watch?v=4q-keGvUnag

Is C# a 100% Object Oriented Programming Language?

C# is NOT a pure object oriented programming language. 

Object oriented language should support:

1. Encapsulation
2. Polymorphism
3. Inheritance
4. All predefined type are objects
5. All operations performed by sending messages to objects
6. All user-defined types are objects

C# does not support point#4 & 5. 

In C#, predefined type can be struct. Example: integer > public struct Int32

So C# does not qualify as pure object oriented language.

Reference:

• http://www.jvoegele.com/software/langcomp.html
• http://stackoverflow.com/questions/3356464/is-c-sharp-a-100-object-oriented-programming-language