How to Get Tracked Entities

• The Session tracks all changes made to all the entities it has either loaded, stored, deleted, or queried for,
  and persists to the server only what is needed when SaveChanges() is called.

• You can use the session's advanced GetTrackedEntities() method
  to retrieve the list of all entities tracked by the session.

• To check what is the actual type of change made to the entities, see:
  Get entity changes, or Get session changes.

• In this page:

  • Get tracked entities
  • Syntax

Get tracked entities

Tracking stored entities:

using (var session = store.OpenSession())
{
  // Store entities within the session:
  Employee employee1 = new Employee {FirstName = "John", LastName = "Doe"};
  Employee employee2 = new Employee {FirstName = "David", LastName = "Brown"};
  Employee employee3 = new Employee {FirstName = "Tom", LastName = "Miller"};
  session.Store(employee1, "employees/1-A");
  session.Store(employee2, "employees/2-A");
  session.Store(employee3, "employees/3-A");

  // Get tracked entities:
  IDictionary<string, EntityInfo> trackedEntities = session.Advanced.GetTrackedEntities();

  // The session tracks the 3 new stored entities:
  Assert.Equal(3, trackedEntities.Keys.Count);
  var entityInfo = trackedEntities["employees/1-A"];
  Assert.Equal("employees/1-A", entityInfo.Id);
  Assert.True(entityInfo.Entity is Employee);
  
  // Save changes:
  session.SaveChanges();
  
  // The session keeps tracking the entities even after SaveChanges is called:
  trackedEntities = session.Advanced.GetTrackedEntities();
  Assert.Equal(3, trackedEntities.Keys.Count);
}

Tracking loaded and deleted entities:

using (var session = store.OpenSession())
{
  // Load entity:
  Employee employee1 = session.Load<Employee>("employees/1-A");
  
  // Delete entity:
  session.Delete("employees/3-A");
  
  // Get tracked entities:
  IDictionary<string, EntityInfo> trackedEntities = session.Advanced.GetTrackedEntities();
  
  // The session tracks the 2 entities:
  Assert.Equal(2, trackedEntities.Keys.Count);
  
  // Note the 'IsDeleted' property that is set for deleted entities:
  var entityInfo = trackedEntities["employees/3-A"];
  Assert.True(entityInfo.IsDeleted);
  
  // Save changes:
  session.SaveChanges();
}

Tracking queried entities:

using (var session = store.OpenSession())
{
  // Query for all employees:
  var employees = session.Query<Employee>().ToList();
  
  // Get tracked entities:
  IDictionary<string, EntityInfo> trackedEntities = session.Advanced.GetTrackedEntities();
  
  // The session tracks the entities loaded via the query:
  Assert.Equal(2, trackedEntities.Keys.Count); 
}

Syntax

IDictionary<string, EntityInfo> GetTrackedEntities();

public class EntityInfo
{
  public string Id { get; set; }
  public object Entity { get; set; }
  public bool IsDeleted { get; set; }
}