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: ShopNest store backend

The Retail team building ShopNest store backend uses Repository Pattern to hide EF queries behind IProductRepository for testability. shoppers and admins never see the C# code — they just get a fast, reliable cart, orders, and inventory API.

Production-style code

public class ShopDbContext : DbContext
{
    public ShopDbContext(DbContextOptions<ShopDbContext> options) : base(options) { }
    // DbSet properties for Repository Pattern
}

What happens in production: In ShopNest store backend, getting Repository Pattern right means shoppers and admins trust the cart, orders, and inventory API every day.

Lesson example (start here)

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

public class ShopDbContext : DbContext
{
    public ShopDbContext(DbContextOptions<ShopDbContext> options) : base(options) { }
    // DbSet properties for Repository Pattern
}

Line-by-line walkthrough

How it works (big picture)

• Study the example line by line.
• Each part connects to Repository Pattern.
• Edit one line, save, run dotnet run, and see what changes.

Do this on your computer

1. Update ShopDbContext or your entity classes.
2. Create or apply a migration if the schema changed.
3. Query or save data and verify in SSMS or Azure Data Studio.
4. Read the real-world section and name which part of the app uses this topic.
5. Run the example locally with dotnet run and confirm the same behavior.
6. 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.
• Add one more property to the entity class and create a migration.
• Use dotnet watch run while editing Repository Pattern — the app restarts on save.

Remember

You learned what Repository Pattern is and when to use it in ShopNest. Practice by changing the example yourself. Use the Next link when you can explain it in your own words.

Common questions