ObjectContext.AttachTo Method (String, Object)
Attaches an object or object graph to the object context in a specific entity set.
Assembly: System.Data.Entity (in System.Data.Entity.dll)
The entity is null.
Invalid entity set.
The object has a temporary key.
The object does not have an EntityKey and no entity set is provided.
Any object from the object graph has a temporary EntityKey.
Any object from the object graph has an invalid EntityKey (for example, values in the key do not match values in the object).
The entity set could not be found from a given entitySetName name and entity container name.
Any object from the object graph already exists in another state manager.
Call ObjectContext to attach the object to a specific entity set in the object context or if the object has a null (Nothing in Visual Basic) EntityKey value. For more information, see Attaching and Detaching Objects.on the
The object being attached can be a single object or be part of the graph.
The rules for the entitySetName format are as follows:
If the DefaultContainerName property is null, then the entitySetName has to be fully qualified as in <Entity Container Name>.<Entity Set Name>.
If the DefaultContainerName is not null, then the entitySetName can be either <Entity Container Name>.<Entity Set Name> or <Entity Set Name>.
The object being attached is not required to have an EntityKey associated with it. If the object does not have an entity key, then entitySetName cannot be an empty string.
If the object being attached has an EntityKey and entitySetName has a value, then the EntitySet of the entity key must match the EntitySet that was found based on the entitySetName and entity container name.
Available since 3.5