There are many ways to insert new data into your database. You can add new objects to the collection, as we did in previous chapters. You can also set the state to Added on each entity. If you are adding entities that contain child entities, the Added state is propagated to all the objects in the graph. In other words, Entity Framework assumes that you are attaching a new object graph if the root entity is new. The object graph term typically refers to a number of related entities that form a complex tree structure. For example, if we have a person object with a number of phone numbers contained in a list property on the Person class, we are dealing with an object graph, where the person entity is a root object. Phone entities are, in essence, children of that person object. Since we have seen a simple functionality, let's work through this complex addition scenario.

First, we will create a new person instance with phone numbers. Then, we will add this person...