How to C#: Creating a simple CRUD page with Blazor and EntityFrameworkCore

Blazor, part of the .NET ecosystem, enables developers to build interactive web applications using C#. In this guide, we'll create a simple CRUD (Create, Read, Update, Delete) application using Blazor and Entity Framework Core in .NET 8.

---

Prerequisites

• .NET 8 SDK: Ensure you have the latest .NET 8 SDK installed. You can download it from the official .NET website.

• Blazor Project: Create a new Blazor Server or WebAssembly project.

• NuGet Packages: Add the following packages to your project:
  

  <ItemGroup>
      <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.0" />
      <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.0" />
      <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="8.0.0" />
  </ItemGroup>

---

Step 1: Set Up the Data Model

Define a simple data model, for example, a Product class:

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
}

Create a DbContext to manage the database operations:

public class AppDbContext : DbContext
{
    public DbSet<Product> Products { get; set; }

    public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { }
}

---

Step 2: Configure the Database Connection

In your appsettings.json, add the connection string:

{
  "ConnectionStrings": {
    "DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=BlazorCrudDb;Trusted_Connection=True;"
  }
}

In Program.cs, register the AppDbContext with the dependency injection container:

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

---

Step 3: Create the Database

Use Entity Framework Core tools to create the database:

1. Open the Package Manager Console.
2. Run the following commands:

   Add-Migration InitialCreate
   Update-Database

---

Step 4: Build the Blazor Components

Create a Blazor component, e.g., ProductList.razor, to handle CRUD operations:

@page "/products"
@inject AppDbContext Context

<h3>Product List</h3>

<table>
    <thead>
        <tr>
            <th>Name</th>
            <th>Price</th>
            <th>Actions</th>
        </tr>
    </thead>
    <tbody>
        @foreach (var product in products)
        {
            <tr>
                <td>@product.Name</td>
                <td>@product.Price</td>
                <td>
                    <button @onclick="() => EditProduct(product.Id)">Edit</button>
                    <button @onclick="() => DeleteProduct(product.Id)">Delete</button>
                </td>
            </tr>
        }
    </tbody>
</table>

<h3>Add/Edit Product</h3>
<input @bind="currentProduct.Name" placeholder="Name" />
<input @bind="currentProduct.Price" placeholder="Price" />
<button @onclick="SaveProduct">Save</button>

@code {
    private List<Product> products;
    private Product currentProduct = new Product();

    protected override async Task OnInitializedAsync()
    {
        products = await Context.Products.ToListAsync();
    }

    private async Task SaveProduct()
    {
        if (currentProduct.Id == 0)
        {
            Context.Products.Add(currentProduct);
        }
        else
        {
            Context.Products.Update(currentProduct);
        }
        await Context.SaveChangesAsync();
        products = await Context.Products.ToListAsync();
        currentProduct = new Product();
    }

    private void EditProduct(int id)
    {
        currentProduct = products.FirstOrDefault(p => p.Id == id);
    }

    private async Task DeleteProduct(int id)
    {
        var product = await Context.Products.FindAsync(id);
        if (product != null)
        {
            Context.Products.Remove(product);
            await Context.SaveChangesAsync();
            products = await Context.Products.ToListAsync();
        }
    }
}

---

Step 5: Run and Test the Application

Run your Blazor application and navigate to /products. You should be able to add, edit, and delete products, with changes reflected in the database.

---

Conclusion

You've now created a basic CRUD application using Blazor and Entity Framework Core in .NET 8. This setup provides a solid foundation for building more complex applications.