What is Entity Framework?

In this article, we will try to answer the following questions

• What is Entity Framework?
• What are Entity Framework Approaches?
• What is Context Class and Entity Class?

So let's get started ....

What is Entity Framework?

Entity Framework is an O/RM Framework, which stands for Object/Relational Mapping Framework.

Purpose: The main purpose of any O/RM or Entity Framework is to automatically generate

• Database, tables & Stored Procedures
• Data Access Code
• Data Saving or Storage Code

Advantage: It helps us to create or update our application quickly and reduce time of production of quality software.

What are Entity Framework Approaches?

The are 3 approaches/methods to use Entity Framework.

• Database First
• Code First
• Model First

Note: Database First & Code First are the most commonly used approaches of Entity Framework. So, we will only concentrate on them.

Database First Approach:

• We use Database First Approach, when we already have database. 
• In this approach, Entity Framework generates the context class and entities classes from our existing Database.

Code First Approach:

• We use Code First Approach, when we don’t have database. 
• In this approach, we create context class and entities classes ourselves from which Database is generated automatically.

What is Context Class and Entity Class?

Context Class:

• The context class is used to query or do CRUD operations or any other operations to our database.
• The context class should be derived from DbContext class.
• In the case of Database First Approach, the context class is generated for us.
• In the case of Code First Approach, we create context class ourselves.

Entity Classes:

• Each entity class represents the corresponding database Table plus all related tables.
• In the case of Database First Approach, all entity classes are also generated for us.
• In the case of Code First Approach, we create entity classes ourselves.