Entity Framework Core — Introduction and Setup

Introduction

Entity Framework Core is Microsoft's ORM — map C# classes to SQL Server tables and query with LINQ instead of raw SQL. ShopNest Inventory starts here.

After this article you will

• Compare EF Core vs Dapper vs ADO.NET
• Install packages and configure DbContext
• Define DbSet entities for inventory
• Verify database connection on startup

Prerequisites

• Article 12 — Static Files, Bundling and Minification
• ShopNest.Web project from prior lessons

Concept deep-dive

public class InventoryDbContext : DbContext
{
    public InventoryDbContext(DbContextOptions<InventoryDbContext> options) : base(options) { }
    public DbSet<Product> Products => Set<Product>();
    public DbSet<Warehouse> Warehouses => Set<Warehouse>();
}

// Program.cs
builder.Services.AddDbContext<InventoryDbContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));

Hands-on — ShopNest Inventory Management

1. dotnet add package Microsoft.EntityFrameworkCore.SqlServer
2. Connection string in appsettings.json
3. Create Product entity and DbContext
4. dotnet ef database update (after first migration in Article 14)

Common errors & best practices

• Connection string wrong — test with SSMS first.
• DbContext registered as Singleton — must be Scoped.

Interview questions

Q: What is DbContext?
A: Unit of work + session to database; tracks changes and SaveChanges persists.

Summary

• EF Core maps classes to tables via DbContext
• Use SQL Server provider for ShopNest inventory
• Choose ORM based on app complexity

Previous: Static Files, Bundling and Minification
Next: EF Core Code First

FAQ