ORM is an abbreviation for Object/Relational mapping. It is a programming methodology to outline with the information put away in the database. It streamlines information creation, information control, and information get to.

Sleep design contains numerous interfaces, for example, Configuration, SessionFactory, Session, Transaction, and so forth.

The center interfaces of Hibernate system are:

• Configuration
• SessionFactory
• Session
• Query
• Criteria
• Transaction

ORM has the accompanying points of interest over JDBC:

• Application improvement is quick.
• Management of exchange.
• Generates key consequently.
• Details of SQL inquiries are covered up.

The objects of criteria are utilized for the creation and execution of the protest situated criteria inquiries.

A portion of the databases upheld by Hibernate are:

• DB2
• MySQL
• Oracle
• Sybase SQL Server
• Informix Dynamic Server
• HSQL
• PostgreSQL
• FrontBase

Key parts of Hibernate are:

• Configuration
• Session
• Session Factory
• Criteria
• Query
• Transaction

• Database Connection
• Class Mapping Setup

The SQL question is made with the assistance of the accompanying sentence structure:

Session.createSQLQuery

Sleep Query Language

The HQL question is made with the assistance of the accompanying sentence structure:

Session.CreateQuery

A model is added to a SQL question by utilizing the Session.createCriteria.

Classes whose objects are put away in a database table are called as steady classes.

SessionFactory gives the case of Session. It is a processing plant of Session. It holds the information of second dimension reserve that isn’t empowered as a matter of course.

Indeed, SessionFactory is a string safe question, numerous strings can’t get to it at the same time.

• It keeps up an association between the sleep application and database.
• It gives techniques to store, refresh, erase or bring information from the database, for example, continue(), refresh(), erase(), stack(), get() and so on.
• It is a manufacturing plant of Query, Criteria and Transaction i.e. it gives production line strategies to restore these occurrences.

No, Session isn’t a string safe question, numerous strings can get to it at the same time. As it were, you can share it between strings

• SessionFactory processing plant = cfg.buildSessionFactory();
• Session session1 = factory.openSession();
• Employee e1 = (Employee) session1.get(Employee.class, Integer.valueOf(101));//passing id of representative
• session1.close();
• e1.setSalary(70000);
• Session session2 = factory.openSession();
• Employee e2 = (Employee) session1.get(Employee.class, Integer.valueOf(101));//passing same id
• Transaction tx=session2.beginTransaction();
• session2.merge(e1);
• tx.commit();
• session2.close();

Subsequent to shutting session1, e1 is in separated state. It won’t be in the session1 store. So in the event that you call refresh() technique, it will toss a blunder.

At that point, we opened another session and stacked a similar Employee example. In the event that we call converge in session2, changes of e1 will be converged in e2.

There are 3 conditions of the question (occurrence) in rest.

• Transient: The question is in a transient state in the event that it is simply made yet has no essential key (identifier) and not related to a session.
• Persistent: The protest is in a steady state if a session is open, and you simply spared the occurrence in the database or recovered the occasion from the database.

• Detached: The question is in a confined state if a session is shut. After withdrew express, the question comes to tenacious state on the off chance that you call bolt() or refresh() strategy.

There are 3 different ways of legacy mapping in sleep.

• Table per progression

• Table per solid class

• Table per subclass

In the event that you stamp a class as mutable=”false”, the class will be treated as a permanent class. Of course, it is mutable=”true”.

The programmed filthy checking highlight of Hibernate, calls refresh proclamation consequently on the articles that are adjusted in an exchange.

We should comprehend it by the model given beneath:

• SessionFactory processing plant = cfg.buildSessionFactory();

• Session session1 = factory.openSession();

• Transaction tx=session2.beginTransaction();

• Employee e1 = (Employee) session1.get(Employee.class, Integer.valueOf(101));

• e1.setSalary(70000);

• tx.commit();

• session1.close();

Here, subsequent to getting worker occasion e1 and we are changing the condition of e1.

In the wake of changing the state, we are submitting the exchange. In such a case, the state will be refreshed consequently. This is known as messy checking in sleep.

There can be 4 sorts of affiliation mapping in rest.

• One to One

• One to Many

• Many to One

• Many to Many

No, gathering mapping must be performed with One-to-Many and Many-to-Many.

Sluggish stacking in rest enhances the execution. It stacks the kid protests on interest.

Since Hibernate 3, apathetic stacking is empowered naturally, and you don’t have to do lazy=”true”. It implies not to stack the youngster objects when the parent is stacked.

Sleep Query Language is known as a question arranged inquiry dialect. It resembles an organized question dialect (SQL).

The principle favorable position of HQL over SQL is:

• You don’t have to learn SQL
• Database free
• Simple to compose a question

String

int

20

DriverManagerConnectionProvider

Yes ,you can.

yes ,You can

yes ,you can

Lazy Loading.

It will use property name as column name.

java.io.Serializable.

java.io.Serializable.

Yes you can but not recommendable.

con.setTransactionIsolation(1/2/4/8)

con.setTransactionIsolation(C onnecton.TRANSACTION_REPEATABLE_READ)

false

Database Vender Specific Default Transaction Isolation Level will be used.

Transaction will be ended when you call commit() or rollback().

By disabling autocommit().

Con.setAutoCommit(false);

• Collection Mapping
• Inheritance Mapping
• Association Mapping

• First Level Cache
• Second Level cache

• One-to-One mapping
• One-to-Many Mapping
• Many-to-Many Mapping