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What is Session flush in NHibernate?
An nHibernate session maintains all changes to the object model. At some point, it needs to synchronize these changes with the database. This ‘synchronization’ is called flushing and it happens at various points in a session’s lifecycle.
What is session beginTransaction ()?
A transaction is associated with a Session and is usually instantiated by a call to Session. beginTransaction(). A single session might span multiple transactions since the notion of a session (a conversation between the application and the datastore) is of coarser granularity than the notion of a transaction.
Why SessionFactory is used in hibernate?
SessionFactory is an Interface which is present in org. hibernate package and it is used to create Session Object. It is immutable and thread-safe in nature. buildSessionFactory() method gathers the meta-data which is in the cfg Object.
Where is hibernate CFG XML?
One of the most required configuration file in Hibernate is hibernate. cfg. xml file. By default, it is placed under src/main/resource folder.
What is the purpose of session beginTransaction ()?
That is, they open contextual session (if needed) and begin transaction when you enter such a method, and commit the transaction and close the session (if needed) when you return from it.
What is difference between session and session factory?
SessionFactory is a factory class for Session objects. It is available for the whole application while a Session is only available for particular transaction. Session is short-lived while SessionFactory objects are long-lived. SessionFactory provides a second level cache and Session provides a first level cache.
What is difference between EntityManagerFactory and SessionFactory?
Using EntityManagerFactory approach allows us to use callback method annotations like @PrePersist, @PostPersist,@PreUpdate with no extra configuration. Using similar callbacks while using SessionFactory will require extra efforts. Related Hibernate docs can be found here and here.
What is the use of Hibernate CFG XML file?
Hibernate Configuration File(cfg file) is the file loaded into an hibernate application when working with hibernate. Hibernate uses this file to establish connection to the database server.It is an XML file which is used to define below information. Standard name for this file is hibernate.
How to do database transactions in NHibernate 5.0?
In line 5 we could some work with the database, e.g., add, update, query or delete objects. In line 6 we commit the transaction. And finally, we close the session again in line 8. So, it’s not a lot of code here.
How does the session object work in NHibernate?
The session object keeps track of all objects you load, new objects you add, existing objects you delete and changes you make to any of these objects. Only when flushing the session will the database be altered (that is: will the necessary create, update and delete statements be sent to the database).
How does unit of work relate to NHibernate?
Since a UoW (Unit of Work) is basically a wrapper around a NHibernate session object I’ll need to open such a session whenever I start a new UoW. But to be able to get such a session NHibernate has to be configured and a NHibernate Session Factory has to be available.
Is there an ORM implementation for NHibernate?
In order to create loose coupling architecture on my web applications, I have created my own implementation for ORM, in this case, NHibernate. I want you please to review the code and tell me if you think it can work in a real world on high traffic app. I have divided the API to transaction and session.