Complete Hibernate 3.0 Tutorial From Rose India

What is Hibernate?Hibernate 3.0, the latest Open Source persistence technology at the heart of J2EE EJB 3.0 is available for download from Hibernet.org.The Hibernate 3.0 core is 68,549 lines of Java code together with 27,948 lines of unit tests, all freely available under the LGPL, and has been in development for well over a year. Hibernate maps the Java classes to the database tables. It also provides the data query and retrieval facilities that significantly reduces the development time. Hibernate is not the best solutions for data centric applications that only uses the stored-procedures to implement the business logic in database. It is most useful with object-oriented domain modes and business logic in the Java-based middle-tier. Hibernate allows transparent persistence that enables the applications to switch any database. Hibernate can be used in Java Swing applications, Java Servlet-based applications, or J2EE applications using EJB session beans.

Features of Hibernate

Hibernate 3.0 provides three full-featured query facilities: Hibernate Query Language, the newly enhanced Hibernate Criteria Query API, and enhanced support for queries expressed in the native SQL dialect of the database.

Filters for working with temporal (historical), regional or permissioned data.

Enhanced Criteria query API: with full support for projection/aggregation and subselects.

Runtime performance monitoring: via JMX or local Java API, including a second-level cache browser.

Eclipse support, including a suite of Eclipse plug-ins for working with Hibernate 3.0, including mapping editor, interactive query prototyping, schema reverse engineering tool.

Hibernate is Free under LGPL: Hibernate can be used to develop/package and distribute the applications for free.

Hibernate is Scalable: Hibernate is very performant and due to its dual-layer architecture can be used in the clustered environments.

Less Development Time: Hibernate reduces the development timings as it supports inheritance, polymorphism, composition and the Java Collection framework.

Automatic Key Generation: Hibernate supports the automatic generation of primary key for your.

JDK 1.5 Enhancements: The new JDK has been released as a preview earlier this year and we expect a slow migration to the new 1.5 platform throughout 2004. While Hibernate3 still runs perfectly with JDK 1.2, Hibernate3 will make use of some new JDK features. JSR 175 annotations, for example, are a perfect fit for Hibernate metadata and we will embrace them aggressively. We will also support Java generics, which basically boils down to allowing type safe collections.

http://www.hibernate.org/Download/DownloadOverview

EJB3-style persistence operations: EJB3 defines the create() and merge() operations, which are slightly different to Hibernate's saveOrUpdate() and saveOrUpdateCopy() operations. Hibernate3 will support all four operations as methods of the Session interface.

Hibernate XML binding enables data to be represented as XML and POJOs interchangeably.

The EJB3 draft specification support for POJO persistence and annotations.

Detailed features are available at http://www.hibernate.org/About/RoadMap.

Hibernate Architecture

In this lesson you will learn the architecture of Hibernate. The following diagram describes the high level architecture of hibernate:

The above diagram shows that Hibernate is using the database and configuration data to provide persistence services (and persistent objects) to the application.

To use Hibernate, it is required to create Java classes that represents the table in the database and then map the instance variable in the class with the columns in the database. Then Hibernate can be used to perform operations on the database like select, insert, update and delete the records in the table. Hibernate automatically creates the query to perform these operations.

Hibernate architecture has three main components:

http://www.hibernate.org/About/RoadMap

Connection ManagementHibernate Connection management service provide efficient management of the database connections. Database connection is the most expensive part of interacting with the database as it requires a lot of resources of open and close the database connection.

Transaction management:Transaction management service provide the ability to the user to execute more than one database statements at a time.

Object relational mapping:Object relational mapping is technique of mapping the data representation from an object model to a relational data model. This part of the hibernate is used to select, insert, update and delete the records form the underlying table. When we pass an object to a Session.save() method, Hibernate reads the state of the variables of that object and executes the necessary query.

Hibernate is very good tool as far as object relational mapping is concern, but in terms of connection management and transaction management, it is lacking in performance and capabilities. So usually hibernate is being used with other connection management and transaction management tools. For example apache DBCP is used for connection pooling with the Hibernate.

Hibernate provides a lot of flexibility in use. It is called "Lite" architecture when we only uses the object relational mapping component. While in "Full Cream" architecture all the three component Object Relational mapping, Connection Management and Transaction Management) are used.

Writing First Hibernate Code

In this section I will show you how to create a simple program to insert record in MySQL database. You can run this program from Eclipse or from command prompt as well. I am assuming that you are familiar with MySQL and Eclipse environment.

Configuring HibernateIn this application Hibernate provided connection pooling and transaction management is used for simplicity. Hibernate uses the hibernate.cfg.xml to create the connection pool and setup required environment.

Here is the code:

<?xml version='1.0' encoding='utf-8'?><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD//EN""http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration><session-factory>

<property name="hibernate.connection.driver_class">

com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">

jdbc:mysql://localhost/hibernatetutorial</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password"></property> <property name="hibernate.connection.pool_size">10</property> <property name="show_sql">true</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.hbm2ddl.auto">update</property>  <mapping resource="contact.hbm.xml"/></session-factory></hibernate-configuration>

In the above configuration file we specified to use the "hibernatetutorial" which is running on localhost and the user of the database is root with no password. The dialect property is org.hibernate.dialect.MySQLDialect which tells the Hibernate that we are using MySQL Database. Hibernate supports many database. With the use of the Hibernate (Object/Relational Mapping and Transparent Object Persistence for Java and SQL Databases), we can use the following databases dialect type property:

DB2 - org.hibernate.dialect.DB2Dialect HypersonicSQL - org.hibernate.dialect.HSQLDialect Informix - org.hibernate.dialect.InformixDialect Ingres - org.hibernate.dialect.IngresDialect Interbase - org.hibernate.dialect.InterbaseDialect Pointbase - org.hibernate.dialect.PointbaseDialect PostgreSQL - org.hibernate.dialect.PostgreSQLDialect Mckoi SQL - org.hibernate.dialect.MckoiDialect Microsoft SQL Server - org.hibernate.dialect.SQLServerDialect MySQL - org.hibernate.dialect.MySQLDialect Oracle (any version) - org.hibernate.dialect.OracleDialect Oracle 9 - org.hibernate.dialect.Oracle9Dialect Progress - org.hibernate.dialect.ProgressDialect FrontBase - org.hibernate.dialect.FrontbaseDialect SAP DB - org.hibernate.dialect.SAPDBDialect Sybase - org.hibernate.dialect.SybaseDialect Sybase Anywhere - org.hibernate.dialect.SybaseAnywhereDialect

The <mapping resource="contact.hbm.xml"/> property is the mapping for our contact table.

http://www.hibernate.org/

Writing First Persistence ClassHibernate uses the Plain Old Java Objects (POJOs) classes to map to the database table. We can configure the variables to map to the database column. Here is the code for Contact.java:

package roseindia.tutorial.hibernate;

/** * @author Deepak Kumar * * Java Class to map to the datbase Contact Table */public class Contact { private String firstName; private String lastName; private String email; private long id;

/** * @return Email */ public String getEmail() { return email; }

/** * @return First Name */ public String getFirstName() { return firstName; }

/** * @return Last name */ public String getLastName() { return lastName; }

/** * @param string Sets the Email */ public void setEmail(String string) { email = string; }

/** * @param string Sets the First Name */ public void setFirstName(String string) { firstName = string; }

/** * @param string sets the Last Name */ public void setLastName(String string) {

lastName = string; }

/** * @return ID Returns ID */ public long getId() { return id; }

/** * @param l Sets the ID */ public void setId(long l) { id = l; }

}

Mapping the Contact Object to the Database Contact tableThe file contact.hbm.xml is used to map Contact Object to the Contact table in the database. Here is the code for contact.hbm.xml:

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> <class name="roseindia.tutorial.hibernate.Contact" table="CONTACT"> <id name="id" type="long" column="ID" > <generator class="assigned"/> </id>

<property name="firstName"> <column name="FIRSTNAME" /> </property> <property name="lastName"> <column name="LASTNAME"/> </property> <property name="email"> <column name="EMAIL"/> </property> </class></hibernate-mapping>

Setting Up MySQL DatabaseIn the configuration file(hibernate.cfg.xml) we have specified to use hibernatetutorial database running on localhost. So, create the databse ("hibernatetutorial") on the MySQL server running on localhost.

Developing Code to Test Hibernate exampleNow we are ready to write a program to insert the data into database. We should first understand about the Hibernate's Session. Hibernate Session is the main runtime interface between a Java application and Hibernate. First we are required to get the Hibernate Session.SessionFactory allows application to create the Hibernate Sesssion by reading the configuration from hibernate.cfg.xml file. Then the save method on session object is used to save the contact information to the database:

session.save(contact)

Here is the code of FirstExample.java


import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;

/** * @author Deepak Kumar * * http://www.roseindia.net * Hibernate example to inset data into Contact table */public class FirstExample { public static void main(String[] args) { Session session = null;

try{ // This step will read hibernate.cfg.xml

and prepare hibernate for use SessionFactory sessionFactory = new

Configuration().configure().buildSessionFactory(); session =sessionFactory.openSession(); //Create new instance of Contact and set

values in it by reading them from form object System.out.println("Inserting Record"); Contact contact = new Contact(); contact.setId(3); contact.setFirstName("Deepak"); contact.setLastName("Kumar"); contact.setEmail("[email protected]"); session.save(contact); System.out.println("Done");

}catch(Exception e){ System.out.println(e.getMessage()); }finally{ // Actual contact insertion will happen at this step session.flush(); session.close();

} }

}

In the next section I will show how to run and test the program.

Running First Hibernate 3.0 Example

Hibernate is free open source software it can be download from http://www.hibernate.org/6.html. Visit the site and download Hibernate 3.0. You can download the Hibernate and install it yourself. But I have provided very thing in one zip file. Download the example code and library from here and extract the content in your favorite directory say "C:\hibernateexample". Download file contains the Eclipse project. To run the example you should have the Eclipse IDE on your machine. Start the Eclipse project and select Java Project as shown below.

http://roseindia.net/hibernate/hibernate.zip

http://www.hibernate.org/6.html

Click on "Next" button. In the next screen leave the output folder as default "hibernateexample/bin".

Click on the "Finish" button.

Now Open the FirstExample.java in the editor as show below.

Copy contact.hbm.xml, and hibernate.cfg.xml in the bin directory of the project using windows explorer. To run the example select Run-> Run As -> Java Application from the menu bar as shown below.

This will run the Hibernate example program in Eclipse following output will displayed on the Eclipse Console.

In this section I showed you how to run the our first Hibernate 3.0 example.

Understanding Hibernate O/R Mapping

In the last example we created contact.hbm.xml to map Contact Object to the Contact table in the database. Now let's understand the each component of the mapping file.

To recall here is the content of contact.hbm.xml:

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> <class name="roseindia.tutorial.hibernate.Contact" table="CONTACT"> <id name="id" type="long" column="ID" > <generator class="assigned"/> </id>

<property name="firstName"> <column name="FIRSTNAME" /> </property> <property name="lastName"> <column name="LASTNAME"/> </property> <property name="email"> <column name="EMAIL"/> </property> </class></hibernate-mapping>

Hibernate mapping documents are simple xml documents. Here are important elements of the mapping file:.

1. <hibernate-mapping> elementThe first or root element of hibernate mapping document is <hibernate-mapping> element. Between the <hibernate-mapping> tag class element(s) are present.

2. <class> elementThe <Class> element maps the class object with corresponding entity in the database. It also tells what table in the database has to access and what column in that table it should use. Within one <hibernate-mapping> element, several <class> mappings are possible.

3. <id> elementThe <id> element in unique identifier to identify and object. In fact <id> element map with the primary key of the table. In our code :<id name="id" type="long" column="ID" >primary key maps to the ID field of the table CONTACT. The attributes of the id element are:

name: The property name used by the persistent class. column: The column used to store the primary key value. type: The Java data type used. unsaved-value: This is the value used to determine if a class has been made persistent. If

the value of the id attribute is null, then it means that this object has not been persisted.

4. <generator> elementThe <generator> method is used to generate the primary key for the new record. Here is some of the commonly used generators :

* Increment - This is used to generate primary keys of type long, short or int that are unique only. It should not be used in the clustered deployment environment. * Sequence - Hibernate can also use the sequences to generate the primary key. It can be used with DB2, PostgreSQL, Oracle, SAP DB databases. * Assigned - Assigned method is used when application code generates the primary key.

5. <property> elementThe property elements define standard Java attributes and their mapping into database schema. The property element supports the column child element to specify additional properties, such as the index name on a column or a specific column type.

Understanding Hibernate <generator> element

In this lesson you will learn about hibernate <generator> method in detail. Hibernate generator element generates the primary key for new record. There are many options provided by the generator method to be used in different situations.

The <generator> element

This is the optional element under <id> element. The <generator> element is used to specify the class name to be used to generate the primary key for new record while saving a new record. The <param> element is used to pass the parameter (s) to the class. Here is the example of generator element from our first application:<generator class="assigned"/>In this case <generator> element do not generate the primary key and it is required to set the primary key value before calling save() method.

Here are the list of some commonly used generators in hibernate:

Generator Description

incrementIt generates identifiers of type long, short or int that are unique only when no other process is inserting data into the same table. It should not the used in the clustered environment.

identityIt supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.

sequenceThe sequence generator uses a sequence in DB2, PostgreSQL, Oracle, SAP DB, McKoi or a generator in Interbase. The returned identifier is of type long, short or int

hilo

The hilo generator uses a hi/lo algorithm to efficiently generate identifiers of type long, short or int, given a table and column (by default hibernate_unique_key and next_hi respectively) as a source of hi values. The hi/lo algorithm generates identifiers that are unique only for a particular database. Do not use this generator with connections enlisted with JTA or with a user-supplied connection.

seqhiloThe seqhilo generator uses a hi/lo algorithm to efficiently generate identifiers of type long, short or int, given a named database sequence.

uuidThe uuid generator uses a 128-bit UUID algorithm to generate identifiers of type string, unique within a network (the IP address is used). The UUID is encoded as a string of hexadecimal digits of length 32.

guid It uses a database-generated GUID string on MS SQL Server and MySQL.

nativeIt picks identity, sequence or hilo depending upon the capabilities of the underlying database.

assignedlets the application to assign an identifier to the object before save() is called. This is the default strategy if no <generator> element is specified.

selectretrieves a primary key assigned by a database trigger by selecting the row by some unique key and retrieving the primary key value.

foreignuses the identifier of another associated object. Usually used in conjunction with a <one-to-one> primary key association.

Using Hibernate <generator> to generate id incrementally

As we have seen in the last section that the increment class generates identifiers of type long, short or int that are unique only when no other process is inserting data into the same table. In this lesson I will show you how to write running program to demonstrate it. You should not use this method to generate the primary key in case of clustured environment.

In this we will create a new table in database, add mappings in the contact.hbm.xml file, develop the POJO class (Book.java), write the program to test it out.

Create Table in the mysql database:User the following sql statement to create a new table in the database. CREATE TABLE `book` ( `id` int(11) NOT NULL default '0', `bookname` varchar(50) default NULL, PRIMARY KEY (`id`) ) TYPE=MyISAM

Developing POJO Class (Book.java)Book.java is our POJO class which is to be persisted to the database table "book".

/** * @author Deepak Kumar * * http://www.roseindia.net * Java Class to map to the database Book table */package roseindia.tutorial.hibernate;

public class Book {

private long lngBookId; private String strBookName; /** * @return Returns the lngBookId. */ public long getLngBookId() { return lngBookId; } /** * @param lngBookId The lngBookId to set. */ public void setLngBookId(long lngBookId) { this.lngBookId = lngBookId; } /** * @return Returns the strBookName. */ public String getStrBookName() { return strBookName; } /** * @param strBookName The strBookName to set. */ public void setStrBookName(String strBookName) { this.strBookName = strBookName; }

}

Adding Mapping entries to contact.hbm.xmlAdd the following mapping code into the contact.hbm.xml file

<class name="roseindia.tutorial.hibernate.Book" table="book"> <id name="lngBookId" type="long" column="id" > <generator class="increment"/> </id>

<property name="strBookName"> <column name="bookname" /> </property></class>

Note that we have used increment for the generator class. *After adding the entries to the xml file copy it to the bin directory of your hibernate eclipse project(this step is required if you are using eclipse).

Write the client program and test it outHere is the code of our client program to test the application.

/**

* @author Deepak Kumar * * http://www.roseindia.net * Example to show the increment class of hibernate generator element to * automatically generate the primay key */package roseindia.tutorial.hibernate;

//Hibernate Importsimport org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;

public class IdIncrementExample { public static void main(String[] args) { Session session = null;

try{ // This step will read hibernate.cfg.xml and prepare hibernate for use SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session =sessionFactory.openSession(); org.hibernate.Transaction tx = session.beginTransaction(); //Create new instance of Contact and set values in it by reading them from form object System.out.println("Inserting Book object into database.."); Book book = new Book(); book.setStrBookName("Hibernate Tutorial"); session.save(book); System.out.println("Book object persisted to the database."); tx.commit(); session.flush(); session.close(); }catch(Exception e){ System.out.println(e.getMessage()); }finally{ } }

}

To test the program Select Run->Run As -> Java Application from the eclipse menu bar. This will create a new record into the book table.

Hibernate Update Query

In this tutorial we will show how to update a row with new information by retrieving data from the underlying database using the hibernate. Lets first write a java class to update a row to the database.

Create a java class:Here is the code of our java file (UpdateExample.java), where we will update a field name "InsuranceName" with a value="Jivan Dhara" from a row of the insurance table.

Here is the code of delete query: UpdateExample .java


import java.util.Date;

import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;

public class UpdateExample { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try { SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); Transaction tr = sess.beginTransaction(); Insurance ins = (Insurance)sess.get(Insurance.class, new Long(1)); ins.setInsuranceName("Jivan Dhara"); ins.setInvestementAmount(20000); ins.setInvestementDate(new Date()); sess.update(ins); tr.commit(); sess.close(); System.out.println("Update successfully!"); } catch(Exception e){ System.out.println(e.getMessage()); }

}

}

Download this code.

Output:

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).

log4j:WARN Please initialize the log4j system properly.

Hibernate: select insurance0_.ID as ID0_0_, insurance0_.insurance_name as insurance2_0_0_, insurance0_.invested_amount as invested3_0_0_, insurance0_.investement_date as investem4_0_0_ from insurance insurance0_ where insurance0_.ID=?

Hibernate: update insurance set insurance_name=?, invested_amount=?, investement_date=? where ID=?

Update successfully!

Hibernate Delete Query

In this lesson we will show how to delete rows from the underlying database using the hibernate. Lets first write a java class to delete a row from the database.

Create a java class:Here is the code of our java file (DeleteHQLExample.java), which we will delete a row from the insurance table using the query "delete from Insurance insurance where id = 2"

Here is the code of delete query: DeleteHQLExample.java


import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;

public class DeleteHQLExample { /** * @author vinod Kumar * * http://www.roseindia.net Hibernate Criteria Query Example * */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try { SessionFactory fact = new

http://roseindia.net/hibernate/UpdateExample.java

Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String hql = "delete from Insurance insurance where id = 2"; Query query = sess.createQuery(hql); int row = query.executeUpdate(); if (row == 0){ System.out.println("Doesn't deleted any row!"); } else{ System.out.println("Deleted Row: " + row); } sess.close(); } catch(Exception e){ System.out.println(e.getMessage()); } }

}

Download this code.

Output:



Hibernate: delete from insurance where ID=2

Deleted Row: 1

Hibernate Query Language

Hibernate Query Language or HQL for short is extremely powerful query language. HQL is much like SQL and are case-insensitive, except for the names of the Java Classes and properties. Hibernate Query Language is used to execute queries against database. Hibernate automatically generates the sql query and execute it against underlying database if HQL is used in the application. HQL is based on the relational object models and makes the SQL object oriented. Hibernate Query Language uses Classes and properties instead of tables and columns. Hibernate Query Language is extremely powerful and it supports Polymorphism, Associations, Much less verbose than SQL.

There are other options that can be used while using Hibernate. These are Query By Criteria (QBC) and Query BY Example (QBE) using Criteria API and the Native SQL queries. In this lesson we will understand HQL in detail.

http://roseindia.net/hibernate/DeleteHQLExample.java

Why to use HQL?

Full support for relational operations: HQL allows representing SQL queries in the form of objects. Hibernate Query Language uses Classes and properties instead of tables and columns.

Return result as Object: The HQL queries return the query result(s) in the form of object(s), which is easy to use. This elemenates the need of creating the object and populate the data from result set.

Polymorphic Queries: HQL fully supports polymorphic queries. Polymorphic queries results the query results along with all the child objects if any.

Easy to Learn: Hibernate Queries are easy to learn and it can be easily implemented in the applications.

Support for Advance features: HQL contains many advance features such as pagination, fetch join with dynamic profiling, Inner/outer/full joins, Cartesian products. It also supports Projection, Aggregation (max, avg) and grouping, Ordering, Sub queries and SQL function calls.

Database independent: Queries written in HQL are database independent (If database supports the underlying feature).

Understanding HQL SyntaxAny Hibernate Query Language may consist of following elements:

Clauses Aggregate functions Subqueries

Clauses in the HQL are:

from select where order by group by

Aggregate functions are:

avg(...) , sum(...), min(...), max(...) count(*) count(...), count(distinct ...), count(all...)

http://roseindia.net/hibernate/hibernate-count.shtml

http://roseindia.net/hibernate/hibernate-max.shtml

http://roseindia.net/hibernate/hibernate-min.shtml

http://roseindia.net/hibernate/groupbyclauseexample.shtml

http://roseindia.net/hibernate/hibernate-avg.shtml

http://roseindia.net/hibernate/groupbyclauseexample.shtml

http://roseindia.net/hibernate/hibernateorderbyexample.shtml

http://roseindia.net/hibernate/hqlwhereclauseexample.shtml

http://roseindia.net/hibernate/selectclause.shtml

http://roseindia.net/hibernate/hibernatefromclauseexample.shtml

SubqueriesSubqueries are nothing but its a query within another query. Hibernate supports Subqueries if the underlying database supports it.

Preparing table for HQL Examples

In this lesson we will create insurance table and populate it with the data. We will use insurance table for rest of the HQL tutorial.

To create the insurance table and insert the sample data, run the following sql query:

/*Table structure for table ìnsurance` */

drop table if exists ìnsurance`;

CREATE TABLE ìnsurance` ( ÌD` int(11) NOT NULL default '0', ìnsurance_name` varchar(50) default NULL, ìnvested_amount` int(11) default NULL, ìnvestement_date` datetime default NULL, PRIMARY KEY (ÌD`)) TYPE=MyISAM;

/*Data for the table ìnsurance` */

insert into ìnsurance` values (1,'Car Insurance',1000,'2005-01-05 00:00:00');insert into ìnsurance` values (2,'Life Insurance',100,'2005-10-01 00:00:00');insert into ìnsurance` values (3,'Life Insurance',500,'2005-10-15 00:00:00');insert into ìnsurance` values (4,'Car Insurance',2500,'2005-01-01 00:00:00');insert into ìnsurance` values (5,'Dental Insurance',500,'2004-01-01 00:00:00');insert into ìnsurance` values (6,'Life Insurance',900,'2003-01-01 00:00:00');insert into ìnsurance` values (7,'Travel Insurance',2000,'2005-02-02 00:00:00');insert into ìnsurance` values (8,'Travel Insurance',600,'2005-03-03 00:00:00');insert into ìnsurance` values (9,'Medical Insurance',700,'2005-04-04 00:00:00');insert into ìnsurance` values (10,'Medical Insurance',900,'2005-03-03 00:00:00');insert into ìnsurance` values (11,'Home Insurance',800,'2005-02-02 00:00:00');insert into ìnsurance` values (12,'Home Insurance',750,'2004-09-09 00:00:00');insert into ìnsurance` values

(13,'Motorcycle Insurance',900,'2004-06-06 00:00:00');insert into `insurance` values (14,'Motorcycle Insurance',780,'2005-03-03 00:00:00');

Above Sql query will create insurance table and add the following data:

ID insurance_name invested_amount investement_date

1 Car Insurance 1000 2005-01-05 00:00:00

2 Life Insurance 100 2005-10-01 00:00:00

3 Life Insurance 500 2005-10-15 00:00:00

4 Car Insurance 2500 2005-01-01 00:00:00

5 Dental Insurance 500 2004-01-01 00:00:00

6 Life Insurance 900 2003-01-01 00:00:00

7 Travel Insurance 2000 2005-02-02 00:00:00

8 Travel Insurance 600 2005-03-03 00:00:00

9 Medical Insurance 700 2005-04-04 00:00:00

10 Medical Insurance 900 2005-03-03 00:00:00

11 Home Insurance 800 2005-02-02 00:00:00

12 Home Insurance 750 2004-09-09 00:00:00

13 Motorcycle Insurance 900 2004-06-06 00:00:00

14 Motorcycle Insurance 780 2005-03-03 00:00:00

In the future lessons we will use this table to write different HQL examples.

Writing ORM for Insurance table

In this lesson we will write the java class and add necessary code in the contact.hbm.xml file.

Create POJO class:Here is the code of our java file (Insurance.java), which we will map to the insurance table.


import java.util.Date;/** * @author Deepak Kumar * * http://www.roseindia.net * Java Class to map to the database insurance table

*/public class Insurance { private long lngInsuranceId; private String insuranceName; private int investementAmount; private Date investementDate; /** * @return Returns the insuranceName. */ public String getInsuranceName() { return insuranceName; } /** * @param insuranceName The insuranceName to set. */ public void setInsuranceName(String insuranceName) { this.insuranceName = insuranceName; } /** * @return Returns the investementAmount. */ public int getInvestementAmount() { return investementAmount; } /** * @param investementAmount The investementAmount

to set. */ public void setInvestementAmount(int investementAmount)

{ this.investementAmount = investementAmount; } /** * @return Returns the investementDate. */ public Date getInvestementDate() { return investementDate; } /** * @param investementDate The investementDate to set. */ public void setInvestementDate(Date investementDate) { this.investementDate = investementDate; } /** * @return Returns the lngInsuranceId. */ public long getLngInsuranceId() { return lngInsuranceId; } /** * @param lngInsuranceId The lngInsuranceId to set. */

public void setLngInsuranceId(long lngInsuranceId) { this.lngInsuranceId = lngInsuranceId; }

}

Adding mappings into contact.hbm.xml fileAdd the following code into contact.hbm.xml file.

<class name="roseindia.tutorial.hibernate.Insurance" table="insurance">

<id name="lngInsuranceId" type="long" column="ID" >

<generator class="increment"/></id>

<property name="insuranceName"><column name="insurance_name" />

</property><property name="investementAmount">

<column name="invested_amount" /></property><property name="investementDate">

<column name="investement_date" /></property>

</class>

Now we have created the POJO class and necessary mapping into contact.hbm.xml file.

HQL from clause Example

In this example you will learn how to use the HQL from clause. The from clause is the simplest possible Hibernate Query. Example of from clause is:

from Insurance insurance

Here is the full code of the from clause example:


import org.hibernate.Session;import org.hibernate.*;import org.hibernate.cfg.*;

import java.util.*;

/** * @author Deepak Kumar * * http://www.roseindia.net * Select HQL Example */public class SelectHQLExample {

public static void main(String[] args) { Session session = null;

try{ // This step will read hibernate.cfg.xml and prepare hibernate for use SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session =sessionFactory.openSession(); //Using from Clause String SQL_QUERY ="from Insurance insurance"; Query query = session.createQuery(SQL_QUERY); for(Iterator it=query.iterate();it.hasNext();){Insurance insurance=(Insurance)it.next(); System.out.println("ID: " + insurance.getLngInsuranceId()); System.out.println("First Name: " + insurance.getInsuranceName()); } session.close();}catch(Exception e){ System.out.println(e.getMessage());}finally{ }

}

}

To run the example select Run-> Run As -> Java Application from the menu bar. Following out is displayed in the Eclipse console:



Hibernate: select insurance0_.ID as col_0_0_ from insurance insurance0_

ID: 1

Hibernate: select insurance0_.ID as ID0_, insurance0_.insurance_name as insurance2_2_0_, insurance0_.invested_amount as invested3_2_0_, insurance0_.investement_date as investem4_2_0_

from insurance insurance0_ where insurance0_.ID=?

First Name: Car Insurance

ID: 2

Hibernate: select insurance0_.ID as ID0_, insurance0_.insurance_name as insurance2_2_0_, insurance0_.invested_amount as invested3_2_0_, insurance0_.investement_date as investem4_2_0_ from insurance insurance0_ where insurance0_.ID=?

First Name: Life Insurance

ID: 3



ID: 4


First Name: Car Insurance

ID: 5


First Name: Dental Insurance

ID: 6



ID: 7


First Name: Travel Insurance

ID: 8


First Name: Travel Insurance

ID: 9


First Name: Medical Insurance

ID: 10


First Name: Medical Insurance

ID: 11


First Name: Home Insurance

ID: 12


First Name: Home Insurance

ID: 13


First Name: Motorcycle Insurance

ID: 14


First Name: Motorcycle Insurance

Hibernate Select Clause

In this lesson we will write example code to select the data from Insurance table using Hibernate Select Clause. The select clause picks up objects and properties to return in the query result set. Here is the query:

Select insurance.lngInsuranceId, insurance.insuranceName, insurance.investementAmount, insurance.investementDate from Insurance insurance

which selects all the rows (insurance.lngInsuranceId, insurance.insuranceName, insurance.investementAmount, insurance.investementDate) from Insurance table.

Hibernate generates the necessary sql query and selects all the records from Insurance table. Here is the code of our java file which shows how select HQL can be used:



import java.util.*;

/** * @author Deepak Kumar * * http://www.roseindia.net * HQL Select Clause Example */public class SelectClauseExample { public static void main(String[] args) { Session session = null;

try{ // This step will read hibernate.cfg.xml

and prepare hibernate for use SessionFactory sessionFactory = new

Configuration().configure()

.buildSessionFactory(); session =sessionFactory.openSession(); //Create Select Clause HQL String SQL_QUERY ="Select insurance.

lngInsuranceId,insurance.insuranceName," + "insurance.investementAmount,insurance.

investementDate from Insurance insurance"; Query query = session.createQuery(SQL_QUERY); for(Iterator it=query.iterate();it.hasNext();){ Object[] row = (Object[]) it.next(); System.out.println("ID: " + row[0]); System.out.println("Name: " + row[1]); System.out.println("Amount: " + row[2]); } session.close(); }catch(Exception e){ System.out.println(e.getMessage()); }finally{ } }

}


Hibernate: select insurance0_.ID as col_0_0_, insurance0_.insurance_name as col_1_0_, insurance0_.invested_amount as col_2_0_, insurance0_.investement_date as col_3_0_ from insurance insurance0_

ID: 1

Name: Car Insurance

Amount: 1000

ID: 2

Name: Life Insurance

Amount: 100

ID: 3


Amount: 500

ID: 4

Name: Car Insurance

Amount: 2500

ID: 5

Name: Dental Insurance

Amount: 500

ID: 6


Amount: 900

ID: 7

Name: Travel Insurance

Amount: 2000

ID: 8


Amount: 600

ID: 9

Name: Medical Insurance

Amount: 700

ID: 10


Amount: 900

ID: 11

Name: Home Insurance

Amount: 800

ID: 12


Amount: 750

ID: 13

Name: Motorcycle Insurance

Amount: 900

ID: 14


Amount: 780

Hibernate Count QueryIn this section we will show you, how to use the Count Query. Hibernate supports multiple aggregate functions. when they are used in HQL queries, they return an aggregate value (such as sum, average, and count) calculated from property values of all objects satisfying other query criteria. These functions can be used along with the distinct and all options, to return aggregate values calculated from only distinct values and all values (except null values), respectively. Following is a list of aggregate functions with their respective syntax; all of them are self-explanatory.

count( [ distinct | all ] object | object.property )

count(*) (equivalent to count(all ...), counts null values also)

sum ( [ distinct | all ] object.property)

avg( [ distinct | all ] object.property)

max( [ distinct | all ] object.property)

min( [ distinct | all ] object.property)

Here is the java code for counting the records from insurance table:


import java.util.Iterator;import java.util.List;

import org.hibernate.Query;import org.hibernate.Session;

import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;

public class HibernateHQLCountFunctions {

/** * */ public static void main(String[] args) { // TODO Auto-generated method stub

Session sess = null; int count = 0; try { SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String SQL_QUERY = "select count(*)from Insurance insurance group by insurance.lngInsuranceId"; Query query = sess.createQuery(SQL_QUERY); for (Iterator it = query.iterate(); it.hasNext();) { it.next(); count++; } System.out.println("Total rows: " + count); sess.close(); } catch(Exception e){ System.out.println(e.getMessage()); } }

}

Download this code.

Output:



Hibernate: select count(*) as col_0_0_ from insurance insurance0_ group by insurance0_.ID

Total rows: 6

http://roseindia.net/hibernate/HibernateHQLCountFunctions.java

Hibernate Avg() Function (Aggregate Functions)

In this section, we will show you, how to use the avg() function. Hibernate supports multiple aggregate functions. When they are used in HQL queries, they return an aggregate value ( such as avg(...), sum(...), min(...), max(...) , count(*), count(...), count(distinct ...), count(all...) ) calculated from property values of all objects satisfying other query criteria.

Following is a aggregate function (avg() function) with their respective syntax.

avg( [ distinct | all ] object.property):

The avg() function aggregates the average value of the given column.

Table Name: insurance

IDinsurance_name

invested_amount

investement_date

2 Life Insurance 250000000-00-00 00:00:00

1 Givan Dhara 20000 2007-07-30 17:29:05

3 Life Insurance 5002005-10-15 00:00:00

4 Car Insurance 25002005-01-01 00:00:00

5Dental Insurance

5002004-01-01 00:00:00

6 Life Insurance 9002003-01-01 00:00:00

7 Travel Insurance

2000 2005-02-02 00:00:00

Here is the java code to retrieve the average value of "invested_amount" column from insurance table:



import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;

public class HibernateHQLAvgFunction {

/** * @Vinod kumar */ public static void main(String[] args) { // TODO Auto-generated method stub

Session sess = null; try { SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String SQL_QUERY = "select avg(investementAmount) from Insurance insurance"; Query query = sess.createQuery(SQL_QUERY); List list = query.list(); System.out.println("Average of Invested Amount: " + list.get(0)); } catch(Exception e){ System.out.println(e.getMessage()); } }

}

Download this Code.

Output:



Hibernate: select avg(insurance0_.invested_amount) as col_0_0_ from insurance insurance0_

Average of Invested Amount: 7342.8571

Hibernate Min() Function (Aggregate Functions)

In this section, we will show you, how to use the Min() function. Hibernate supports multiple aggregate functions. When they are used in HQL queries, they return an aggregate value ( such as avg(...), sum(...), min(...), max(...) , count(*), count(...), count(distinct ...), count(all...) ) calculated from property values of all objects satisfying other query criteria.

Following is a aggregate function (min() function) with their respective syntax.

min( [ distinct | all ] object.property)

http://roseindia.net/hibernate/HibernateHQLAvgFunction.java

The Min() function aggregates the minimum value of the given column.

Table Name: insurance

IDinsurance_name

invested_amount

investement_date

2 Life Insurance 250000000-00-00 00:00:00

1 Givan Dhara 20000 2007-07-30 17:29:05

3 Life Insurance 5002005-10-15 00:00:00

4 Car Insurance 25002005-01-01 00:00:00

5Dental Insurance

5002004-01-01 00:00:00

6 Life Insurance 9002003-01-01 00:00:00

7 Travel Insurance

2000 2005-02-02 00:00:00

Here is the java code to retrieve the minimum value of "invested_amount" column from insurance table:


import java.util.List;


public class HibernateHQLMinFunction {

/** * @Vinod Kumar */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try { SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String SQL_QUERY = "select min(investementAmount) from Insurance insurance"; Query query = sess.createQuery(SQL_QUERY); List list = query.list(); System.out.println("Min

Invested Amount: " + list.get(0)); } catch(Exception e){ System.out.println(e.getMessage()); } }

}

Download this Code.

Output:



Hibernate: select min(insurance0_.invested_amount) as col_0_0_ from insurance insurance0_

Min Invested Amount: 500

HQL Where Clause Example

Where Clause is used to limit the results returned from database. It can be used with aliases and if the aliases are not present in the Query, the properties can be referred by name. For example:

from Insurance where lngInsuranceId='1'

Where Clause can be used with or without Select Clause. Here the example code:



import java.util.*;

/** * @author Deepak Kumar * * http://www.roseindia.net * HQL Where Clause Example * Where Clause With Select Clause Example */public class WhereClauseExample {

http://roseindia.net/hibernate/HibernateHQLMinFunction.java

public static void main(String[] args) { Session session = null;

try{ // This step will read hibernate.cfg.xml and prepare hibernate for use SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session =sessionFactory.openSession(); System.out.println("*******************************"); System.out.println("Query using Hibernate Query Language"); //Query using Hibernate Query Language String SQL_QUERY =" from Insurance as insurance where insurance.lngInsuranceId='1'"; Query query = session.createQuery(SQL_QUERY); for(Iterator it=query.iterate();it.hasNext();){ Insurance insurance=(Insurance)it.next(); System.out.println("ID: " + insurance.getLngInsuranceId()); System.out.println("Name: " + insurance. getInsuranceName()); } System.out.println("*******************************"); System.out.println("Where Clause With Select Clause"); //Where Clause With Select Clause SQL_QUERY ="Select insurance.lngInsuranceId,insurance.insuranceName," + "insurance.investementAmount,insurance.investementDate from Insurance insurance "+ " where insurance.lngInsuranceId='1'"; query = session.createQuery(SQL_QUERY); for(Iterator it=query.iterate();it.hasNext();){ Object[] row = (Object[]) it.next(); System.out.println("ID: " + row[0]); System.out.println("Name: " + row[1]); } System.out.println("*******************************");

session.close(); }catch(Exception e){ System.out.println(e.getMessage());

}finally{ } }

}


*******************************

Query using Hibernate Query Language

Hibernate: select insurance0_.ID as col_0_0_ from insurance insurance0_ where (insurance0_.ID='1')

ID: 1


Name: Car Insurance

*******************************

Where Clause With Select Clause

Hibernate: select insurance0_.ID as col_0_0_, insurance0_.insurance_name as col_1_0_, insurance0_.invested_amount as col_2_0_, insurance0_.investement_date as col_3_0_ from insurance insurance0_ where (insurance0_.ID='1')

ID: 1

Name: Car Insurance

*******************************

HQL Group By Clause Example

Group by clause is used to return the aggregate values by grouping on returned component. HQL supports Group By Clause. In our example we will calculate the sum of invested amount in each insurance type. Here is the java code for calculating the invested amount insurance wise:

package roseindia.tutorial.hibernate;import org.hibernate.Session;import org.hibernate.*;import org.hibernate.cfg.*;import java.util.*;

/** * @author Deepak Kumar * * http://www.roseindia.net HQL Group by Clause Example * */public class HQLGroupByExample { public static void main(String[] args) { Session session = null; try { // This step will read hibernate.cfg.xml and prepare hibernate for // use SessionFactory sessionFactory = new Configuration().configure() .buildSessionFactory(); session = sessionFactory.openSession(); //Group By Clause Example String SQL_QUERY = "select sum(insurance.investementAmount),insurance.insuranceName " + "from Insurance insurance group by insurance.insuranceName"; Query query = session.createQuery(SQL_QUERY); for (Iterator it = query.iterate(); it.hasNext();) { Object[] row = (Object[]) it.next(); System.out.println("Invested Amount: " + row[0]); System.out.println("Insurance Name: " + row[1]); } session.close(); } catch (Exception e) { System.out.println(e.getMessage()); } finally { } }

}


Hibernate: select sum(insurance0_.invested_amount) as col_0_0_, insurance0_.insurance_name as col_1_0_ from insurance insurance0_ group by insurance0_.insurance_name

Invested Amount: 3500

Insurance Name: Car Insurance


Insurance Name: Dental Insurance


Insurance Name: Home Insurance


Insurance Name: Life Insurance


Insurance Name: Medical Insurance


Insurance Name: Motorcycle Insurance


Insurance Name: Travel Insurance

HQL Order By Example

Order by clause is used to retrieve the data from database in the sorted order by any property of returned class or components. HQL supports Order By Clause. In our example we will retrieve the data sorted on the insurance type. Here is the java example code:

package roseindia.tutorial.hibernate;import org.hibernate.Session;import org.hibernate.*;import org.hibernate.cfg.*;import java.util.*;/** * @author Deepak Kumar * * http://www.roseindia.net HQL Order by Clause Example * */public class HQLOrderByExample { public static void main(String[] args) { Session session = null; try { // This step will read hibernate.cfg.xml and prepare hibernate for // use SessionFactory sessionFactory = new Configuration().configure() .buildSessionFactory();

session = sessionFactory.openSession(); //Order By Example String SQL_QUERY = " from Insurance as insurance order by insurance.insuranceName"; Query query = session.createQuery(SQL_QUERY); for (Iterator it = query.iterate(); it.hasNext();) { Insurance insurance = (Insurance) it.next(); System.out.println("ID: " + insurance.getLngInsuranceId()); System.out.println("Name: " + insurance.getInsuranceName()); } session.close(); } catch (Exception e) { System.out.println(e.getMessage()); } finally { } }

}


Hibernate: select insurance0_.ID as col_0_0_ from insurance insurance0_ order by insurance0_.insurance_name

ID: 1


Name: Car Insurance

ID: 4


Name: Car Insurance

ID: 5


Name: Dental Insurance

ID: 11



ID: 12



ID: 2



ID: 3



ID: 6



ID: 9



ID: 10

Hibernate: select insurance0_.ID as ID0_, insurance0_.insurance_name as insurance2_2_0_,

insurance0_.invested_amount as invested3_2_0_, insurance0_.investement_date as investem4_2_0_ from insurance insurance0_ where insurance0_.ID=?


ID: 13



ID: 14



ID: 7



ID: 8



Hibernate Criteria Query Example

The Criteria interface allows to create and execute object-oriented queries. It is powerful alternative to the HQL but has own limitations. Criteria Query is used mostly in case of multi criteria search screens, where HQL is not very effective.

The interface org.hibernate.Criteria is used to create the criterion for the search. The org.hibernate.Criteria interface represents a query against a persistent class. The Session is a factory for Criteria instances. Here is a simple example of Hibernate Criterial Query:


import org.hibernate.Session;import org.hibernate.*;import org.hibernate.cfg.*;import java.util.*;/** * @author Deepak Kumar * * http://www.roseindia.net Hibernate Criteria Query Example * */public class HibernateCriteriaQueryExample { public static void main(String[] args) { Session session = null; try { // This step will read hibernate.cfg.xml and prepare hibernate for // use SessionFactory sessionFactory = new Configuration().configure() .buildSessionFactory(); session = sessionFactory.openSession(); //Criteria Query Example Criteria crit = session.createCriteria(Insurance.class); List insurances = crit.list(); for(Iterator it = insurances.iterator();it.hasNext();){ Insurance insurance = (Insurance) it.next(); System.out.println("ID: " + insurance.getLngInsuranceId()); System.out.println("Name: " + insurance.getInsuranceName()); } session.close(); } catch (Exception e) { System.out.println(e.getMessage()); } finally { } }

}

The above Criteria Query example selects all the records from the table and displays on the console. In the above code the following code creates a new Criteria instance, for the class Insurance:

Criteria crit = session.createCriteria(Insurance.class);

The code:

List insurances = crit.list();

creates the sql query and execute against database to retrieve the data.

Criteria Query Examples

In the last lesson we learnt how to use Criteria Query to select all the records from Insurance table. In this lesson we will learn how to restrict the results returned from the database. Different method provided by Criteria interface can be used with the help of Restrictions to restrict the records fetched from database.

Criteria Interface provides the following methods:

Method Description

addThe Add method adds a Criterion to constrain the results to be retrieved.

addOrder Add an Order to the result set.

createAliasJoin an association, assigning an alias to the joined entity

createCriteriaThis method is used to create a new Criteria, "rooted" at the associated entity.

setFetchSizeThis method is used to set a fetch size for the underlying JDBC query.

setFirstResult This method is used to set the first result to be retrieved.

setMaxResultsThis method is used to set a limit upon the number of objects to be retrieved.

uniqueResult

This method is used to instruct the Hibernate to fetch and return the unique records from database.

Class Restriction provides built-in criterion via static factory methods. Important methods of the Restriction class are:

Method Description

Restriction.allEq

This is used to apply an "equals" constraint to each property in the key set of a Map

Restriction.between

This is used to apply a "between" constraint to the named property

Restriction.eq

This is used to apply an "equal" constraint to the named property

Restriction.ge

This is used to apply a "greater than or equal" constraint to the named property

Restriction.gt

This is used to apply a "greater than" constraint to the named property

Restriction.idEqThis is used to apply an "equal" constraint to the identifier property

Restriction.ilike

This is case-insensitive "like", similar to Postgres ilike operator

Restriction.in This is used to apply an "in" constraint to the named property

Restriction.isNotNullThis is used to apply an "is not null" constraint to the named property

Restriction.isNull This is used to apply an "is null" constraint to the named property

Restriction.le This is used to apply a "less than or equal" constraint to the named property

Restriction.like This is used to apply a "like" constraint to the named property

Restriction.ltThis is used to apply a "less than" constraint to the named property

Restriction.ltProperty This is used to apply a "less than" constraint to two properties

Restriction.ne This is used to apply a "not equal" constraint to the named property

Restriction.nePropertyThis is used to apply a "not equal" constraint to two properties

Restriction.not This returns the negation of an expression

Restriction.or This returns the disjuction of two expressions

Here is an example code that shows how to use Restrictions.like method and restrict the maximum rows returned by query by setting the Criteria.setMaxResults() value to 5.


import org.hibernate.Session;import org.hibernate.*;import org.hibernate.criterion.*;import org.hibernate.cfg.*;import java.util.*;/** * @author Deepak Kumar * * http://www.roseindia.net Hibernate Criteria Query Example * */public class HibernateCriteriaQueryExample2 { public static void main(String[] args) { Session session = null; try { // This step will read hibernate.cfg.xml and prepare hibernate for // use

SessionFactory sessionFactory = new Configuration().configure() .buildSessionFactory(); session = sessionFactory.openSession(); //Criteria Query Example Criteria crit = session.createCriteria(Insurance.class); crit.add(Restrictions.like("insuranceName", "%a%")); //Like condition crit.setMaxResults(5); //Restricts the max rows to 5

List insurances = crit.list(); for(Iterator it = insurances.iterator();it.hasNext();){ Insurance insurance = (Insurance) it.next(); System.out.println("ID: " + insurance.getLngInsuranceId()); System.out.println("Name: " + insurance.getInsuranceName()); } session.close(); } catch (Exception e) { System.out.println(e.getMessage()); } finally { } }

}

Hibernate's Built-in criterion: Between (using Integer)

In this tutorial,, you will learn to use "between" with the Integer class. "Between" when used with the Integer object, It takes three parameters e.g. between("property_name",min_int,max_int).

Restriction class provides built-in criterion via static factory methods. One important method of the Restriction class is between : which is used to apply a "between" constraint to the named property

Here is the code of the class using "between" with the Integer class :


import org.hibernate.Session;import org.hibernate.*;import org.hibernate.criterion.*;import org.hibernate.cfg.*;import java.util.*;/** * @author vinod Kumar

* * http://www.roseindia.net Hibernate Criteria Query Example * */public class HibernateCriteriaQueryBetweenTwoInteger { public static void main(String[] args) { Session session = null; try { // This step will read hibernate.cfg.xml and prepare hibernate for // use SessionFactory sessionFactory = new Configuration().configure() .buildSessionFactory(); session = sessionFactory.openSession(); //Criteria Query Example Criteria crit = session.createCriteria(Insurance.class); crit.add(Expression.between("investementAmount", new Integer(1000), new Integer(2500))); //Between condition crit.setMaxResults(5); //Restricts the max rows to 5

List insurances = crit.list(); for(Iterator it = insurances.iterator();it.hasNext();){ Insurance insurance = (Insurance) it.next(); System.out.println("ID: " + insurance.getLngInsuranceId()); System.out.println("Name: " + insurance.getInsuranceName()); System.out.println("Amount: " + insurance.getInvestementAmount()); } session.close(); } catch (Exception e) { System.out.println(e.getMessage()); } finally { } }

}

Download this code:

Output:


http://roseindia.net/hibernate/HibernateCriteriaQueryBetweenTwoInteger.java


Hibernate: select this_.ID as ID0_0_, this_.insurance_name as insurance2_0_0_, this_.invested_amount as invested3_0_0_, this_.investement_date as investem4_0_0_ from insurance this_ where this_.invested_amount between ? and ? limit ?

ID: 1

Name: Car Insurance

Amount: 1000

ID: 4

Name: Car Insurance

Amount: 2500

ID: 7


Amount: 2000

Hibernate Native SQL Example

Native SQL is handwritten SQL for all database operations like create, update, delete and select. Hibernate Native Query also supports stored procedures. Hibernate allows you to run Native SQL Query for all the database operations, so you can use your existing handwritten sql with Hibernate, this also helps you in migrating your SQL/JDBC based application to Hibernate.

In this example we will show you how you can use Native SQL with hibernate. You will learn how to use Native to calculate average and then in another example select all the objects from table.

Here is the code of Hibernate Native SQL:


import org.hibernate.Session;import org.hibernate.*;import org.hibernate.criterion.*;import org.hibernate.cfg.*;import java.util.*;/** * @author Deepak Kumar * * http://www.roseindia.net Hibernate Native Query Example *

*/public class NativeQueryExample { public static void main(String[] args) { Session session = null;

try{ // This step will read hibernate.cfg.xml and prepare hibernate for use SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session =sessionFactory.openSession(); /* Hibernate Native Query Average Examle*/ String sql ="select stddev(ins.invested_amount) as stdErr, "+ " avg(ins.invested_amount) as mean "+ " from insurance ins"; Query query = session.createSQLQuery(sql).addScalar("stdErr",Hibernate.DOUBLE). addScalar("mean",Hibernate.DOUBLE); //Double [] amount = (Double []) query.uniqueResult(); Object [] amount = (Object []) query.uniqueResult(); System.out.println("mean amount: " + amount[0]); System.out.println("stdErr amount: " + amount[1]);

/* Example to show Native query to select all the objects from database */ /* Selecting all the objects from insurance table */ List insurance = session.createSQLQuery("select {ins.*} from insurance ins") .addEntity("ins", Insurance.class) .list(); for (Iterator it = insurance.iterator(); it.hasNext();) { Insurance insuranceObject = (Insurance) it.next(); System.out.println("ID: " + insuranceObject.getLngInsuranceId()); System.out.println("Name: " + insuranceObject.getInsuranceName()); } session.close(); }catch(Exception e){ System.out.println(e.getMessage()); e.printStackTrace(); } }

}

Following query is used to calculate the average of invested amount:

/*Hibernate Native Query Average Examle*/

String sql ="select stddev(ins.invested_amount) as stdErr, "+ " avg(ins.invested_amount) as mean "+ " from insurance ins";

The following code:

Query query = session.createSQLQuery(sql).addScalar("stdErr",Hibernate.DOUBLE).addScalar("mean",Hibernate.DOUBLE);

Creates a new instance of SQLQuery for the given SQL query string and the entities returned by the query are detached.

To return all the entities from database we have used the following query:

/* Example to show Native query to select all the objects from database *//* Selecting all the objects from insurance table */List insurance = session.createSQLQuery("select {ins.*} from insurance ins").addEntity("ins", Insurance.class).list(); for (Iterator it = insurance.iterator(); it.hasNext();) { Insurance insuranceObject = (Insurance) it.next(); System.out.println("ID: " + insuranceObject.getLngInsuranceId()); System.out.println("Name: " + insuranceObject.getInsuranceName());}

When you run the program through it should display the following result:



Hibernate: select stddev(ins.invested_amount) as stdErr, avg(ins.invested_amount) as mean from insurance ins

mean amount: 592.1584

stdErr amount: 923.5714

Hibernate: select ins.ID as ID0_, ins.insurance_name as insurance2_2_0_, ins.invested_amount as invested3_2_0_, ins.investement_date as investem4_2_0_ from insurance ins

ID: 1

Name: Car Insurance

ID: 2


ID: 3


ID: 4

Name: Car Insurance

......

.......

In this example you learned how to use Native Query with Hibernate.

Associations and Joins

This section includes a brief introduction about Associations and Joins along with examples.

Association mappings: Association mappings comes in the list of the most difficult thing to get right. This section includes the canonical cases one by one. Here we starts the section from unidirectional mappings and comes to the bi-directional cases.

We'll include the classification of associations that whether they map or not to an intervening join table and by multiplicity.

Here we are not using the Nullable foreign keys since these keys do not require good practice in traditional data modeling. Hibernate does not require the foreign keys since mappings work even if we drop the nullability constraints.

Hibernate HQL Inner Join

Hibernate's HQL language is not capable for handling the "inner join on" clauses. If our domain entity model includes relationships defined between the related objects then the query like this

Query query = session.createQuery("from Car car inner join Owner owner where owner.Name ='Vinod'");

will work. HQL keeps the information of joining the Car and Owner classes according to the association mapping contained in the hbm.xml file. Since the association information is defined in the mapping file so there is no need to stipulate the join in the query. In the above query "from Car car where car.Owner.Name='Vinod'" will work too. Initialization of the collections and many-to-one mapping requires the explicit joins just to avoid lazy load errors.

A unidirectional one-to-many association on a foreign key is rarely required.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/

hibernate-mapping-3.0.dtd">

<hibernate-mapping> <class name="net.roseindia.Dealer"> <id name="id" type="int"> <generator class="increment"/> </id>

<property name="name" type="string"/> <bag name="product" inverse="true" cascade="all,delete-orphan"> <key column="did"/> <one-to-many class="net.roseindia.Product"/> </bag>

</class>

</hibernate-mapping>


<?xml version='1.0' encoding='utf-8'?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> <class name="net.roseindia.Product"> <id name="id" type="int"> <generator class="increment"/> </id>

<property name="name" type="string"/> <property name="did" type="int"/> <property name="price" type="double"/> <many-to-one name="dealer" class="net.roseindia.Dealer" column="did" insert="false" update="false"/>

</class>


Here is the hibernate code:

In this example first we create the session object with the help of the SessionFactory interface. Then we use the createQuery() method of the Session object which returns a Query object. Now we use the openSession() method of the SessionFactory interface simply to instantiate the Session object. And the we retrieve the data from the database store it in that Query object and iterate this object with the help of Iterator and finally displays the requested data on the console.

package net.roseindia;



public class Join {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try{ SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String sql_query = "from Product p inner join p.dealer as d"; Query query = sess.createQuery(sql_query); Iterator ite = query.list().iterator(); System.out.println("Dealer Name\t"+"Product Name\t"+"Price"); while ( ite.hasNext() ) { Object[] pair = (Object[]) ite.next(); Product pro = (Product) pair[0]; Dealer dea = (Dealer) pair[1]; System.out.print(pro.getName()); System.out.print("\t"+dea.getName()); System.out.print("\t\t"+pro.getPrice()); System.out.println(); } sess.close(); } catch(Exception e ){ System.out.println(e.getMessage()); }

}

}

Output:



Hibernate: select product0_.id as id1_0_, dealer1_.id as id0_1_, product0_.name as name1_0_, product0_.did as did1_0_, product0_.price as price1_0_, dealer1_.name as name0_1_ from Product product0_ inner join Dealer dealer1_ on

product0_.did=dealer1_.id

Dealer Name Product Name Price

Computer Agrawal 23000.0

Keyboard Agrawal 1500.0

Computer Agrawal 100.0

Mobile Mohan 15000.0

PenDrive Mohan 200.0

Laptop Ritu 200.0

HardDisk Ritu 2500.0

Hibernate Aggregate Functions(Associations and Joins)

This example tries to make understand about the aggregate function of Hibernate with the help of example.

In Hibernate HQL queries are capable of returning the results of the aggregate functions on properties. Collections can also be used with the aggregate functions with the select clause. Aggregate functions supports the following functions:

min(...), max(...), sum(...), avg(...). count(*) count(distinct...), count(all..), count(...)

The distinct and all keywords used above are identical as in SQL.



<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">



</class>






</class>







public class AggregateFunctionExample {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try{ SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String sql_query = "select d.name,p.name,sum(p.price) as totalprice from Product p join p.dealer d group by p.name"; Query query = sess.createQuery(sql_query); System.out.println("Dealer Name\t"+"Product Name\t"+"Price"); for(Iterator it=query.iterate();it.hasNext();){ Object[] row = (Object[]) it.next(); System.out.print(row[0]); System.out.print("\t\t"+row[1]); System.out.print("\t"+row[2]); System.out.println(); } sess.close(); } catch(Exception e ){ System.out.println(e.getMessage()); } }

}

Output:



Hibernate: select dealer1_.name as col_0_0_, product0_.name as col_1_0_, sum(product0_.price) as col_2_0_ from Product product0_ inner join Dealer dealer1_ on product0_.did=dealer1_.id group by product0_.name


Agrawal Computer 23100.0

Ritu HardDisk 2500.0

Agrawal Keyboard 1500.0

Ritu Laptop 200.0

Mohan Mobile 15000.0

Mohan PenDrive 200.0

Hibernate Subqueries

In this section, you will learn about the subqueries with an appropriate example.

Subqueries in hibernate can be referred as the queries that are surrounded by parentheses (). Subqueries solves the purpose of grouping, ordering , narrowing and aggregating the resultant of the query by using the where clause. Notice that the subqueries get executed prior to the main query. The HQL queries may contain the subqueries only in case of if the subqueries are supported by the underline database.





<property name="name" type="string"/> <bag name="product" inverse="true" cascade="all,delete-orphan"> <key column="did"/> <one-to-many class="net.roseindia.Product"/>

</bag>

</class>






</class>







public class Subqueries {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub

Session sess = null; try{ SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); String sql_query = "select d.name,p.name,p.price from Product p join p.dealer d where p.price in(select p.price from p where p.price > 1500)"; Query query = sess.createQuery(sql_query); System.out.println("Dealer Name\t"+"Product Name\t"+"Price"); for(Iterator it=query.iterate();it.hasNext();){ Object[] row = (Object[]) it.next(); System.out.print(row[0]); System.out.print("\t\t"+row[1]); System.out.print("\t"+row[2]); System.out.println(); } sess.close(); } catch(Exception e ){ System.out.println(e.getMessage()); } }

}

Output:



Hibernate: select dealer1_.name as col_0_0_, product0_.name as col_1_0_, product0_.price as col_2_0_ from Product product0_ inner join Dealer dealer1_ on product0_.did=dealer1_.id where product0_.price in (select product0_.price from Product product0_ where product0_.price>1500)


Agrawal Computer 23000.0

Mohan Mobile 15000.0

Ritu HardDisk 2500.0

Hibernate Projections

In this section, you will learn about the hibernate projections with an appropriate example.

Projections: The package Criteria is used as a framework by the applications just to build the new kinds of projection. may be used by applications as a framework for building new kinds of Projection. In general Projection means to retrieve while in case of SQL Projection means "Select" clause. Most of the applications uses the built-in projection types by means of the static factory methods of this class.

Product.java


public class Product { private int id; private String name; private double price; private Dealer dealer; private int did; public Product(String name, double price) { super(); // TODO Auto-generated constructor stub this.name = name; this.price = price; } public Product() { super(); // TODO Auto-generated constructor stub } public Dealer getDealer() { return dealer; } public void setDealer(Dealer dealer) { this.dealer = dealer; } public double getDid() { return did; } public void setDid(int did) { this.did = did; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; }

}

ProjectionList: is the list of projection instances which are result of Query's object. Criteria API: enables us to specify criteria based on various.

In the class projectionExample.java, first we create the session object with the help of the SessionFactory interface. Then we use the createQuery() method of the Session object which returns a Query object. Now we use the openSession() method of the SessionFactory interface simply to instantiate the Session object.Then we obtain the criteria object simply by invoking the createCriteria() method of the Session's object. Now we create a projectionList object add the fields having properties "name" and "price". Set it to the Criteria object by invoking the setProjection() method and passing the projectList object into this method and then add this object into the List interface's list object and iterate this object list object to display the data contained in this object.

projectionExample.java



import org.hibernate.Criteria;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import org.hibernate.criterion.ProjectionList;import org.hibernate.criterion.Projections;

public class projectionExample {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try{ SessionFactory sfact = new Configuration().configure().buildSessionFactory(); sess = sfact.openSession(); Criteria crit = sess.createCriteria(Product.class); ProjectionList proList = Projections.projectionList(); proList.add(Projections.property("name")); proList.add(Projections.property("price")); crit.setProjection(proList); List list = crit.list(); Iterator it = list.iterator(); if(!it.hasNext()){ System.out.println("No any data!"); } else{ while(it.hasNext()){

Object[] row = (Object[])it.next(); for(int i = 0; i < row.length;i++){ System.out.print(row[i]); System.out.println(); } } } sess.close(); } catch(Exception e){ System.out.println(e.getMessage()); }

}

}

Output:



Hibernate: select this_.name as y0_, this_.price as y1_ from Product this_

Product Name Price

Computer 23000.0

Mobile 15000.0

Laptop 200.0

Keyboard 1500.0

PenDrive 200.0

HardDisk 2500.0

Computer 100.0

Hibernate Projections (rowCount or countDistinct)

In this section, you will learn about the hibernate projection with an example.

Projection Interface: This is an interface that extends the Serializable. An object-oriented representation of a query result set projection in a Criteria query. Built-in projection types are provided by the Projections factory class. The Projection interface might be implemented by application classes that define custom projections.

The following example to count the total number of rows and distinct rows to use the Projections.rowCount() and Projections.countDistinct() method.

Table Name: Insurance

Here is the code of program:



import org.hibernate.Criteria;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import org.hibernate.criterion.Projections;

public class hibernateProjectionExample {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub

Session sess = null; try{ SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); Criteria crit = sess.createCriteria(Insurance.class); crit.setProjection(Projections.rowCount()); List result = crit.list(); System.out.println("No. of rows: "+result); crit.setProjection(Projections.distinct(Projections.countDistinct("insuranceName"))); List distList = crit.list(); System.out.println("Distinct Count: "+ distList); } catch(Exception e){ System.out.println(e.getMessage()); } }

}

Download this Code.

Output:



Hibernate: select count(*) as y0_ from insurance this_

No. of rows: [7]

Hibernate: select distinct count(distinct this_.insurance_name) as y0_ from insurance this_

Distinct Count: [5]

Hibernate Projection Count

In this section, you will learn to hibernate projection count. The example demonstrates the rowCount() method of the projection interface.






</class></hibernate-mapping>


<?xml version='1.0' encoding='utf-8'?><!DOCTYPE hibernate-mapping

http://roseindia.net/hibernate/projections/hibernateProjectionExample.java

PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">



</class> </hibernate-mapping>


In the class projectionExample.java, first we create the session object with the help of the SessionFactory interface. Then we use the createQuery() method of the Session object which returns a Query object. Now we use the openSession() method of the SessionFactory interface simply to instantiate the Session object.

Then we obtain the criteria object simply by invoking the createCriteria() method of the Session's object. Now we set the number of rows count simply by calling the setProjection() method of the Criteria APIs and passing it the rowCount() method of the Projections interface. Then pass the reference of the Criteria object into the List interface object and finally iterate this object to count the number of rows.



import org.hibernate.Criteria;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import org.hibernate.criterion.Projection;import org.hibernate.criterion.Projections;import org.hibernate.criterion.Restrictions;

public class projectionCount {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try {

SessionFactory sfact = new Configuration().configure().buildSessionFactory(); sess = sfact.openSession(); Criteria crit = sess.createCriteria(Product.class); crit.setProjection(Projections.rowCount()); List list = crit.list(); Iterator it = list.iterator(); if (!it.hasNext()){ System.out.println("No any data!"); } else{ while(it.hasNext()){ Object count = it.next(); System.out.println("Row: " + count); } } } catch(Exception e){ System.out.println(e.getMessage()); }

}

}

Output:



Hibernate: select count(*) as y0_ from Product this_

Row: 7

Hibernate Projection Example (Sum)

In this section, you will learn to hibernate aggregate function like: sum() using hibernate projection.

The following example to calculate the sum of invested_amount to the Insurance table

Table Name: Insurance

Here is the code of program:


import java.util.List;

import org.hibernate.Criteria;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import org.hibernate.criterion.ProjectionList;import org.hibernate.criterion.Projections;

public class ProjectionExample1 {

/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Session sess = null; try { SessionFactory fact = new Configuration().configure().buildSessionFactory(); sess = fact.openSession(); Criteria crit = sess.createCriteria(Insurance.class); ProjectionList proList = Projections.projectionList(); proList.add(Projections.sum("investementAmount")); crit.setProjection(proList); List sumResult = crit.list(); System.out.println("Total Invested Amount: " + sumResult); } catch(Exception e){ System.out.println(e.getMessage()); } }

}

Download this Code.

Output:

http://roseindia.net/hibernate/projections/ProjectionExample1.java



Hibernate: select sum(this_.invested_amount) as y0_ from insurance this_

Total Invested Amount: [51400]

Hibernate Types

This section gives you description of all the Types that are supported by Hibernate. A Hibernate Type is used to map a Java property type to a JDBC type or types.

The following tables to represents all Hibernate types:

Interfaces and Descriptions:

AbstractComponentTypeThe AbstractComponentType enables other Component-like types to hold collections and have cascades, etc.

AssociationType This interface used to represent all associations between entities.

DiscriminatorTypeThis interface used to discriminator properties with the help of right mapped subclass.

IdentifierType This interface has All identifiers of entities.

LiteralType This is a maker interface that which store SQL literals.

TypeThis interface describes mapping between the Java and JDBC datatypes

VersionType This interface used for version stamping.

Classes and Descriptions:

AbstractBynaryType The stream of byte bounded into a VAQRBINARY.

AbstractCharArrayType The stream of char bounded into a VARCHAR.

AbstractTypeThis is a superclass that can be used for creating type hierarchy.

AdaptedImmutableType

AnyType It defines 'any' mappings and deprecated 'object' types.

AnyType.ObjectTypeCacheEntry

ArrayType It represents collection of data into a similar types.

BagType

BigDecimaType This class used to mapping between SQL NUMERIC and

java.math.BigDecimal.

BigIntegerTypeThis class used to mapping between SQL NUMERIC and java.math.BigInteger.

BinaryTypeIt used to mapping between a SQL VARBINARY and a Java byte[].

BlobTypeIt used to mapping between a SQL BLOB and java.sql.Blob.

BooleanType This class maps between SQL BIT and Java Boolean.

ByteType This class maps between SQL TINYINT and Java Byte.

CalendarDateTypeThis class represents a data and mapping into a Calendar object.

CalendarTypeIt also represents a datetime mapping into a Calendar object.

CharacterArrayType It is a collection of VARCHAR like: Character[].

CharacterTypeThis class mapping between a SQL CHAR and a Java Character.

CharArrayType It is a collection of VARCHAR like: char[].

CharBooleanTypeThis is a superclass that can be mapping between SQL CHAR and Java boolean.

ClassTypeThis class mapping between SQL VARCHAR and Java class.

ClobTypeThis class mapping between SQL CLOB and java.sql.Clob.

CollectionType It handles the Hibernate PersistentCollections.

ComponentType This class mapping all components.

CompositeCustomType It adjusts CompositeUserType to Type interface.;

CurrencyTypeIt is used to mapping a SQL VARCHAR into a java.util.Currency.

CustomCollectionTypeThis class is created by users and implement the PersistentCollection.

CustomTypeIt adjusts the user type to generic type interface and changes the internal type contracts.

DateType This class mapping between an SQL DATE to Java Date.

DbTimestampType

DoubleTypeIt can be used to mapping between SQL DOUBLE to Java Double.

EmbeddedComponentType

EntityType It communicates an entity class.

FloatType It links SQL FLOAT to Java Float.

ForeignKeyDirectionThis class shows directionality of the foreign key constraint.

IdentifierBagType

ImmutableType This is a superclass of the nullable immutable type.

IntegerType This class links between the SQL INT to Java Integer.

ListType

LocaleType It links into an SQL VARCHAR and a Java Locale.

LongType This class links into an SQL BIGINT and a Java Long.

ManyToOneType It associates many-to-one entity.

MapType

MetaType

MutableType This is a superclass of mutable nullable types.

NullableType This is a supperclass of single-column nullable types.

OneToOneType It associates one-to-one entity.

OrderedMapType

OrderedSetType

PrimitiveTypeThis is the superclass of primitive or primitive wrappers types.

SerializableTypeThis class maps an SQL VARBINARY to a serializable Java object.

SetType

ShortTypeIt communicates between an SQL SMALLINT and Java Short.

SortedMapType

SortedSetType

SpacialOneToOneType

StringTypeIt communicates between an SQL VARCHAR and Java String.

TextType This class links between an SQL CLOB and Java String.

TimestampTypeThis class mapping between an SQL TIMESTAMP and Java java.util.Date or java.sql.Timestamp.

TimeTypeIt maps an SQL TIME to Java java.util.Date or java.sql.Time.

TimeZoneTypeIt communicates an SQL VARCHAR to Java java.util.TimeZone.

TrueFalseType This class maps an SQL CHAR to a Java Boolean.

TypeFactory This class used internally and holds an instance of Type.

WrapperBinaryType

YesNoType It maps between an SQL CHAR to Java Boolean.

Exceptions and Descriptions:

SerializationExceptionThis exception occurs when the property could not be serialized or deserialized.

Complete Hibernate 3.0 Tutorial From Rose India

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