If you’re building applications with .NET, chances are you’ve come across Entity Framework (EF). It’s Microsoft’s flagship Object-Relational Mapper (ORM) that helps developers work with databases using .NET objects, without writing endless SQL queries by hand.

In this post, we’ll explore what EF is, why it’s so widely used, and how you can get started quickly.

What is Entity Framework?

Entity Framework (EF) is an ORM (Object-Relational Mapper) that sits between your C# code and your database. Instead of writing raw SQL to interact with your data, EF allows you to:

• Work with C# classes that represent database tables.
• Query data using LINQ instead of SQL.
• Let EF generate SQL commands under the hood.
• Manage schema changes through migrations.

In other words: EF turns your database into strongly-typed .NET objects.

Why Use Entity Framework?

Here are some of the key benefits developers love:

• Productivity: Write less boilerplate SQL and focus on business logic.
• Maintainability: Strongly-typed interactions make refactoring easier.
• Cross-database support: Works with SQL Server, PostgreSQL, MySQL, SQLite, and more.
• Migrations: Keep your schema in sync with your codebase.

Versions of Entity Framework

There are two major “flavors” of EF you might hear about:

• Entity Framework 6 (EF6) – the older, full-featured framework for .NET Framework projects.
• Entity Framework Core (EF Core) – the modern, lightweight, and cross-platform version built for .NET 5/6/7/8 and beyond.

Today, most new projects use EF Core.

Getting Started with EF Core

Let’s walk through a simple example using EF Core with a SQLite database.

Step 1: Install EF Core

Install the EF Core packages via NuGet:

dotnet add package Microsoft.EntityFrameworkCore
dotnet add package Microsoft.EntityFrameworkCore.Sqlite
dotnet add package Microsoft.EntityFrameworkCore.Tools

Step 2: Create Your Model

Let’s say we’re building a blog system. We define our entities as simple C# classes:

public class Post
{
    public int Id { get; set; }
    public string Title { get; set; } = "";
    public string Content { get; set; } = "";
}

Step 3: Create the Database Context

The DbContext is the bridge between your C# objects and the database.

using Microsoft.EntityFrameworkCore;

public class BlogContext : DbContext
{
    public DbSet<Post> Posts { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseSqlite("Data Source=blog.db");
}

Step 4: Apply Migrations

Migrations create or update the database schema.

dotnet ef migrations add InitialCreate
dotnet ef database update

This will generate a SQLite database (blog.db) with a Posts table.

Step 5: Query Data with LINQ

using var db = new BlogContext();

// Insert a new Post
db.Posts.Add(new Post { Title = "Hello EF Core", Content = "My first blog post!" });
db.SaveChanges();

// Query Posts
var posts = db.Posts.ToList();
foreach (var post in posts)
{
    Console.WriteLine($"{post.Id}: {post.Title}");
}

Best Practices with Entity Framework

• Use Migrations: Keep database schema under version control.
• Leverage AsNoTracking() for read-only queries (performance boost).
• Avoid N+1 queries: Use .Include() to load related data efficiently.
• Keep DbContext scoped per request in web apps (not singleton).

Conclusion

Entity Framework makes database work in .NET much more productive. By mapping your tables to classes and queries to LINQ, you can build applications faster, with cleaner and more maintainable code.

If you’re starting a new project on .NET, EF Core should be high on your list of tools to use.