ASP.NET Core MVC REST API with SQL Server & Entity Framework

In this tutorial, we’ll build a complete REST API using ASP.NET Core MVC with SQL Server and Entity Framework Core. We’ll cover setting up the project, creating a model, controller, and connecting to the database.

🧰 Step 1: Create ASP.NET Core MVC Project

dotnet new webapi -n DotNetRestApi

This creates a Web API project with default REST setup.

📦 Step 2: Add Entity Framework SQL Server

dotnet add package Microsoft.EntityFrameworkCore.SqlServer
dotnet add package Microsoft.EntityFrameworkCore.Tools

🧾 Step 3: Create Model Class

Inside the Models folder, create User.cs:

public class User
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
}

🗃️ Step 4: Create Database Context

Inside Data/ApplicationDbContext.cs:

public class ApplicationDbContext : DbContext
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
    }

    public DbSet<User> Users { get; set; }
}

⚙️ Step 5: Configure Database Connection

In appsettings.json:

"ConnectionStrings": {
  "DefaultConnection": "Server=.;Database=UserApiDb;Trusted_Connection=True;"
}

Update Program.cs or Startup.cs:

builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));

🛠 Step 6: Create Controller

dotnet add package Microsoft.AspNetCore.Mvc.NewtonsoftJson
dotnet add package Microsoft.EntityFrameworkCore.Design

UserController.cs

[ApiController]
[Route("api/[controller]")]
public class UsersController : ControllerBase
{
    private readonly ApplicationDbContext _context;

    public UsersController(ApplicationDbContext context)
    {
        _context = context;
    }

    [HttpGet]
    public async Task<IEnumerable<User>> GetUsers()
    {
        return await _context.Users.ToListAsync();
    }

    [HttpGet("{id}")]
    public async Task<ActionResult<User>> GetUser(int id)
    {
        var user = await _context.Users.FindAsync(id);
        return user == null ? NotFound() : Ok(user);
    }

    [HttpPost]
    public async Task<ActionResult<User>> PostUser(User user)
    {
        _context.Users.Add(user);
        await _context.SaveChangesAsync();
        return CreatedAtAction(nameof(GetUser), new { id = user.Id }, user);
    }

    [HttpPut("{id}")]
    public async Task<IActionResult> PutUser(int id, User user)
    {
        if (id != user.Id) return BadRequest();
        _context.Entry(user).State = EntityState.Modified;
        await _context.SaveChangesAsync();
        return NoContent();
    }

    [HttpDelete("{id}")]
    public async Task<IActionResult> DeleteUser(int id)
    {
        var user = await _context.Users.FindAsync(id);
        if (user == null) return NotFound();
        _context.Users.Remove(user);
        await _context.SaveChangesAsync();
        return NoContent();
    }
}

🧱 Step 7: Run Migrations

dotnet ef migrations add InitialCreate
dotnet ef database update

📡 Step 8: Test API Endpoints

• GET /api/users – Get all users
• GET /api/users/{id} – Get user by ID
• POST /api/users – Create user
• PUT /api/users/{id} – Update user
• DELETE /api/users/{id} – Delete user

🚀 Step 9: Enable CORS

In Program.cs:

builder.Services.AddCors(options =>
{
    options.AddPolicy("AllowAll",
        policy => policy.AllowAnyOrigin().AllowAnyHeader().AllowAnyMethod());
});

app.UseCors("AllowAll");

🎯 Done! Your API is Ready

You’ve now created a full ASP.NET Core Web API with Entity Framework and SQL Server. You can test your API with Postman or connect it to Angular, React, or any frontend.