Cayenne User Documentation
Persistent Object Lifecycle

A lifecycle of a persistent object can be represented as a number of states and transitions between them. These states are formally defined as "int" constants in `org.apache.cayenne.PersistenceState` class. Transitions between states (see the diagram below) occur in response to the application interacting with either persistent objects or Cayenne context. Whenever a transition occurs, Cayenne automatically updates "persistenceState" property of all affected objects by calling `setPersistenceState()`.

A new object state transformations: | A fetched or committed object state transformations:

The states are defined as follows:

State | Value | Description
--- | --- | ---
TRANSIENT | 1 | The object is not registered in a `DataContext` and will not persist.
NEW | 2 | The object is freshly registered in a `DataContext`, but has not been persisted to the database (there is no matching database record).
COMMITTED | 3 | The object is registered in a `DataContext` and has been persisted to the database (there is a matching database record).
MODIFIED | 4 | The object is registered in a `DataContext` and there is a matching database record and the object has been modified in memory, but the changes have not yet been persisted back to the database.
HOLLOW | 5 | The object is registered in a `DataContext` and has a corresponding database row, but the values have not yet been fetched from the database. The values will be fetched/faulted from the database automatically by Cayenne if any fields are requested from the object.
DELETED | 6 | The object is registered in a `DataContext` and will be deleted from the database upon commit.

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