Introduction
CRUD operations (Create, Read, Update, Delete) are fundamental in web development. In this tutorial, we will build a simple blog post application using .NET 9, Entity Framework Core, and SQL Server. By the end, you’ll understand how to implement CRUD operations in a modern .NET web API.
Prerequisites
- .NET 9 SDK installed
- SQL Server instance running
- Visual Studio 2022 or VS Code
- Basic knowledge of C# and SQL
Step 1: Create a .NET 9 Web API Project
dotnet new webapi -n BlogApi cd BlogApi Step 2: Install Entity Framework Core
dotnet add package Microsoft.EntityFrameworkCore.SqlServer dotnet add package Microsoft.EntityFrameworkCore.Tools Step 3: Create the BlogPost Model
namespace BlogApi.Models { public class BlogPost { public int Id { get; set; } public string Title { get; set; } public string Content { get; set; } public DateTime CreatedAt { get; set; } = DateTime.Now; } } Step 4: Setup DbContext
using Microsoft.EntityFrameworkCore; using BlogApi.Models; namespace BlogApi.Data { public class BlogDbContext : DbContext { public BlogDbContext(DbContextOptions<BlogDbContext> options) : base(options) { } public DbSet<BlogPost> BlogPosts { get; set; } } } Add DbContext to Program.cs:
builder.Services.AddDbContext<BlogDbContext>(options => options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"))); And in appsettings.json:
"ConnectionStrings": { "DefaultConnection": "Server=YOUR_SERVER_NAME;Database=BlogDb;Trusted_Connection=True;" } Step 5: Create BlogPosts Controller
using Microsoft.AspNetCore.Mvc; using Microsoft.EntityFrameworkCore; using BlogApi.Data; using BlogApi.Models; namespace BlogApi.Controllers { [ApiController] [Route("api/[controller]")] public class BlogPostsController : ControllerBase { private readonly BlogDbContext _context; public BlogPostsController(BlogDbContext context) { _context = context; } [HttpGet] public async Task<IActionResult> GetAll() => Ok(await _context.BlogPosts.ToListAsync()); [HttpGet("{id}")] public async Task<IActionResult> Get(int id) { var post = await _context.BlogPosts.FindAsync(id); return post == null ? NotFound() : Ok(post); } [HttpPost] public async Task<IActionResult> Create(BlogPost post) { _context.BlogPosts.Add(post); await _context.SaveChangesAsync(); return CreatedAtAction(nameof(Get), new { id = post.Id }, post); } [HttpPut("{id}")] public async Task<IActionResult> Update(int id, BlogPost post) { if (id != post.Id) return BadRequest(); _context.Entry(post).State = EntityState.Modified; await _context.SaveChangesAsync(); return NoContent(); } [HttpDelete("{id}")] public async Task<IActionResult> Delete(int id) { var post = await _context.BlogPosts.FindAsync(id); if (post == null) return NotFound(); _context.BlogPosts.Remove(post); await _context.SaveChangesAsync(); return NoContent(); } } } Step 6: Apply Migrations and Run
dotnet ef migrations add InitialCreate dotnet ef database update dotnet run Test API endpoints using Postman or Swagger.
Conclusion
You now have a fully functional CRUD API using .NET 9 and SQL Server. This structure can be extended to more complex applications, including authentication, pagination, and advanced filtering.
Project Structure
BlogApi/ ├── Controllers/ │ └── BlogPostsController.cs ├── Data/ │ └── BlogDbContext.cs ├── Models/ │ └── BlogPost.cs ├── Program.cs ├── appsettings.json ├── BlogApi.csproj #DotNet9 #SQLServer #CRUD #EntityFrameworkCore #WebAPI #CSharp #FullStack #DotNetDevelopment
Top comments (0)