5. Persistence Contexts

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Both the `org.hibernate.Session` API and `javax.persistence.EntityManager` API represent a context for dealing with persistent data.
This concept is called a `persistence context`.
Persistent data has a state in relation to both a persistence context and the underlying database.

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<dl>
<dt class="hdlist1">`transient`</dt>
<dd>

the entity has just been instantiated and is not associated with a persistence context.
It has no persistent representation in the database and typically no identifier value has been assigned (unless the _assigned_ generator was used).

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<dt class="hdlist1">`managed`, or `persistent`</dt>
<dd>

the entity has an associated identifier and is associated with a persistence context.
It may or may not physically exist in the database yet.

</dd>
<dt class="hdlist1">`detached`</dt>
<dd>

the entity has an associated identifier, but is no longer associated with a persistence context (usually because the persistence context was closed or the instance was evicted from the context)

</dd>
<dt class="hdlist1">`removed`</dt>
<dd>

the entity has an associated identifier and is associated with a persistence context, however it is scheduled for removal from the database.

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Much of the `org.hibernate.Session` and `javax.persistence.EntityManager` methods deal with moving entities between these states.

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