When will you use this?

Use EF Core when your app stores data in SQL Server, PostgreSQL, or SQLite.

• Orders, customers, and products live in SQL Server — EF Core reads and writes them with C#.
• Migrations let teams update database schema without manual SQL scripts in production.

Real-world: Toolliyo-style learning platform

The EdTech / LMS team building Toolliyo-style learning platform uses Introduction to EF Core to read and write SQL Server tables using C# classes instead of raw SQL. students and instructors never see the C# code — they just get a fast, reliable course API and lesson progress tracking.

Production-style code

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

// In a service:
var items = await _db.Products
    .Where(p => p.Price < 1000)
    .OrderBy(p => p.Name)
    .ToListAsync();

What happens in production: In Toolliyo-style learning platform, a solid Introduction to EF Core foundation lets the team ship course API and lesson progress tracking on schedule without environment surprises.

Lesson example (start here)

Copy this smaller example first. Once it works, compare it with the real-world code above.

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

// In a service:
var items = await _db.Products
    .Where(p => p.Price < 1000)
    .OrderBy(p => p.Name)
    .ToListAsync();

Line-by-line walkthrough

How it works (big picture)

• Product class becomes a Products table.
• LINQ queries translate to SQL.
• ToListAsync runs the query asynchronously.

Do this on your computer

1. Install Microsoft.EntityFrameworkCore.SqlServer.
2. Create a Product class and ShopDbContext.
3. Register DbContext in Program.cs.
4. Query products in a controller action.
5. Read the real-world section and name which part of the app uses this topic.
6. Run the example locally with dotnet run and confirm the same behavior.
7. Change one value in the example (route, text, or connection string) and predict what will happen before you save.

Experiments — try changing this

• Change a string or route in the example and save — watch the browser or Swagger response update.
• Break the code on purpose (remove a semicolon), read the error message, then fix it.
• Use dotnet watch run while editing EF Core — the app restarts on save.

Remember

EF Core = C# objects ↔ database tables. Use async LINQ for queries. DbContext is your gateway to the database.

Common questions