Change Tracking — How Your ORM Knows What You Did

We can query. We can materialize. We can join. But saving changes means knowing what changed — and that's where things get philosophically interesting.

Here's something that should bother you about Entity Framework:

var customer = await context.Customers.FindAsync(42);
customer.Name = "New Name";
await context.SaveChangesAsync(); // How does it know?

You loaded an entity. You changed a property. You called SaveChanges. And the ORM generated a precise UPDATE Customers SET Name = @p0 WHERE Id = @p1 — updat…