Getting Started With Entity Framework

Introduction

This article will cover the following things,

• Brief Concepts
• Implementation – Setup Console Application, using EF.
• Implementation – Create DB, using EF Code First approach.
• Implementation – Configure SQL Server. Check the DB and tables.
• Implementation – Implement CRUD operations using EF, using Code First approach.

What is Entity Framework?

• Entity framework is an open source ORM framework from Microsoft.
• It is an enhancement to ADO.NET, which gives the developers an automated mechanism for accessing & storing the data in the database.
• Entity framework is useful in two scenarios.
  
  
• First, if you already have an existing database ahead of other parts of the Application.
• Second, you want to focus on your classes and then create the database from your classes.
  
  

What is O/RM?

• ORM is a tool for storing the data from the domain objects to the relational database like MS SQL Server in an automated way.
• O/RM includes parts:
  
  
• Domain class objects
• Relational database objects
  
  
• Mapping information on how the domain objects map to the relational database objects (tables, views and the stored procedures).
• It also automates the standard CRUD operation (Create, Read, Update & Delete) so that the developer doesn't need to write it manually.

Implementation – Setup Console application using EF

Steps to be followed, 

• Open VS 2015 and create a project.
• Choose Visual C# and console Application.
  
  
  

• Right click on the solution. Click on “Manage NuGet Packages” and browse for Entity framework.
  
  
  

• Install the package with the latest stable version.
  
  
  

• Create a model class “Employee” with the possible properties.
  
  
  

• Add the connection strings settings for e.g. DB Name and Data Source into the App.config file.
  
  
  

• Add the DB context file for the employees names as “EmployeeDbContext”, using the name of the connection string into the base constructor.
  
  
  

• Now, we have created the console Application, using EF and we are good to go now for the creation of the DB.

Implementation – Create DB using EF Code First approach

Steps to be followed,

• Go to the program.cs file in the console Application and write a method for the creation of the DB.
  
  
  

Implementation – Configure SQL Server, check the DB and tables

Steps to be followed,

• Open SQL Server and connect to the DB, using Windows credentials.
  
  
  

• In SQL Server, check for the DB (Demo) and tables (Employees) created, using EF.
  
  
  

Implementation – Implement CRUD operations using EF using Code First approach

READ FUNCTIONALITY

Steps to be followed,

• Open program.cs and create a method Read () to implement GET functionality.
  
  
  

• Run the Application and see the output.
  
  
  

• Look for the row in “Demo” DB and within the table “Employees”.
  
  
  

INSERT FUNCTIONALITY

Steps to be followed,

• Open program.cs and create a method Insert () to implement an add functionality.
  
  
  

• Look for the inserted row in “Demo” DB and within the table “Employees”.
  
  
  

UPDATE FUNCTIONALITY

Steps to be followed,

• Open program.cs and create a method Update () to implement the update functionality.
  
  

• Look for the updated row of EmpId-3 in “Demo” DB and within the table “Employees”.
  
  
  

DELETE FUNCTIONALITY

Steps to be followed,

• Open program.cs and create a method Delete () to implement an add functionality.
  
  
  

• Delete the row with an EmpId -3 in “Demo” DB and within the table “Employees”.