Hibernate Session is a thread-safe and short-lived object
that represents a conversation between the application and the persistence
layer. This is required to perform CRUD operations (Create, Delete,
Update, Retrieval) on a persistent entity in Hibernate. For ColdFusion
applications that use ORM, this session is automatically managed
by ColdFusion. Hibernate sessions also act as the first level of
cache, which ensures that only one copy of an object exists in the
session.
When CRUD operations are performed in the session, data of the
entity is not synchronized with the database immediately. That is,
the SQL statements for the operations are not issued immediately
and they are queued. The data is synchronized with the database
when the session is flushed. When the session is flushed, the SQL
operations are performed in the following order:
all entity insertions, in the same order the corresponding
objects were saved using EntitySave()
all entity updates
all collection deletions
all collection element deletions, updates, and insertions
all collection insertions
all entity deletions, in the same order the corresponding
objects were deleted using EntityDelete()
The only exception to this is that objects with nativeId generation
are inserted immediately when the object is saved.
Note: ColdFusion creates and manages Hibernate sessions only if ormenabled is set
to true in application scope.
When the ColdFusion application starts, it builds the Hibernate
session factory that is available for the application life time.
This factory is used to create Hibernate sessions that manage the
persistent object lifecycle. When the first CRUD method is called,
a Hibernate session gets created and is closed when the request
ends or when the ormclosesessionmethod is called.
For details on how ColdFusion works with Hibernate, see the Architecture.
In multiple data source scenarios supported in ColdFusion 9 Update
1, there are multiple sessions (one for each data source) in the
same request. For all entity functions, the appropriate sessions
are used transparently.
ColdFusion exposes a few methods to let CFML developers work
with the Hibernate sessions directly. ORM session-related functions
also take optional data source argument. If you do not specify a
data source, the default data source specified for ORM is used.
The methods are as follows:
