Getting Started with Entity Framework

Tutorial 4 of 5

Getting Started with Entity Framework

1. Introduction

In this tutorial, we are going to provide an introduction to Entity Framework, an open-source Object-Relational Mapping (ORM) framework for .NET. This is a powerful tool that allows developers to interact with their database using .NET objects. You will learn the basic concepts and features of Entity Framework and how to use it in your .NET applications.

What you'll learn:
- What is Entity Framework
- How to setup and configure Entity Framework
- How to create, read, update and delete operations using Entity Framework

Prerequisites:
- Basic knowledge of .NET and C# programming.
- Basic understanding of SQL and databases.
- Visual Studio installed on your computer.

2. Step-by-Step Guide

  1. Understanding Entity Framework: Entity Framework is an ORM that enables .NET developers to work with relational data using domain-specific objects. It eliminates the need for most of the data-access code that developers usually need to write.

  2. Setting up Entity Framework: To start using Entity Framework, you need to install the EntityFramework NuGet package. In Visual Studio, go to Tools -> NuGet Package Manager -> Manage NuGet Packages for Solution, search for EntityFramework and install it.

  3. Creating a Model: A model is a collection of classes to interact with the database. Each class represents a table in the database.

  4. DbContext: The DbContext class is an important part of Entity Framework. It is a bridge between your domain or entity classes and the database.

  5. Database Operations: With the setup complete, you can now perform create, read, update and delete operations.

3. Code Examples

1. Creating a Model
This is how you create a model class representing a Student table in the database.

public class Student
{
    public int StudentId { get; set; }
    public string StudentName { get; set; }
    // other properties
}

2. Creating a DbContext
Here is how you create a DbContext class.

public class SchoolContext : DbContext
{
    public SchoolContext(): base("SchoolDBConnectionString")
    {
    }
    public DbSet<Student> Students { get; set; }
    // other DbSets
}

3. Adding a new student
This is how create a new student and add it to the database.

using(var context = new SchoolContext())
{
    var std = new Student(){ StudentName = "New Student" };
    context.Students.Add(std);
    context.SaveChanges();
}

4. Summary

In this tutorial, we covered a basic introduction to Entity Framework, how to setup and configure it in your .NET application, and how to create, read, update and delete data in your database using Entity Framework.

For further learning, you should look into:
- Relationships and Navigation Properties
- Migrations in Entity Framework
- Querying data using LINQ and Entity Framework

5. Practice Exercises

Exercise 1: Create a Course model and add some courses to the database.

Exercise 2: Create a relationship between Student and Course models and use it to load related data from the database.

Exercise 3: Use Entity Framework migrations to update your database schema without losing any data.

Solutions and explanations for these exercises can be found in the Entity Framework documentation. Keep practicing and exploring more features of Entity Framework to enhance your .NET development skills.