How to insert nested entities using Entity Framework?

Question

Assume we have an Invoice entity which has many InvoiceDetails.

Each invoice detail has InvoiceId as FK.

How can I insert an Invoice and its' InvoiceDetails using Entity Framework using minimal db connections?

Answer 1

EF uses this way:

context.Invoices.Add(invoice); // invoice contains all invoice details 
context.SaveChanges();

It will use single database connection but each entity will be inserted in separate database roundtrip because EF doesn't support command batching.