The method is designed for creating a new entity instance and simultaneous attaching it to the data context
The method creates a new entity instance of the specified class type. The entity attributes forming the primary key will be initialized by the default values. The entity instance created by this method is initially attached to the data context and placed to the object cache (in contrast to the TCustomEntityContext.CreateEntity method), therefore you can already perform modification operations for the instance: TCustomEntityContext.Delete, TCustomEntityContext.Save, TCustomEntityContext.Cancel, without pre-calling TCustomEntityContext.Attach.
Note, that when using this method, the entity attributes forming the primary key are initialized by the default values, therefore it may cause the exception when attaching the entity to the data context due to unique key violation.
var EmpEntity: TEntity; begin EmpEntity := Context.CreateAttachedEntity(TEmp); // ... end;