Hints
@Inheritance strategy is joined. Used to create joined tables with base class. Each table contains parent table's linked id.
Example
@Entity
@Inheritance(strategy=InheritanceType.JOINED)
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<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>Hibernate017_InheritanceJoined</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>beans</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>beans</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
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create table Consumer
(consumer_id integer not null,
consumer_name varchar(255),
primary key (consumer_id)) ENGINE=InnoDB;
create table InternetConsumer
(packName varchar(255),
consumer_id integer not null,
primary key (consumer_id)) ENGINE=InnoDB;
create table PhoneConsumer
(callPlane varchar(255),
consumer_id integer not null,
primary key (consumer_id)) ENGINE=InnoDB;
alter table InternetConsumer
add index FK3A7022776907180F (consumer_id),
add constraint FK3A7022776907180F foreign key (consumer_id) references Consumer (consumer_id);
alter table PhoneConsumer
add index FK90D807646907180F (consumer_id),
add constraint FK90D807646907180F foreign key (consumer_id) references Consumer (consumer_id);
create table hibernate_sequences
( sequence_name varchar(255),
sequence_next_hi_value integer );
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package com.knowledgewalls.entity;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public class Consumer {
@Id @GeneratedValue(strategy=GenerationType.TABLE)
private int consumer_id;
private String consumer_name;
public int getConsumer_id() {
return consumer_id;
}
public void setConsumer_id(int consumer_id) {
this.consumer_id = consumer_id;
}
public String getConsumer_name() {
return consumer_name;
}
public void setConsumer_name(String consumer_name) {
this.consumer_name = consumer_name;
}
}
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package com.knowledgewalls.entity;
import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;
@Entity
public class InternetConsumer extends Consumer {
private String packName;
public String getPackName() {
return packName;
}
public void setPackName(String packName) {
this.packName = packName;
}
}
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package com.knowledgewalls.entity;
import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;
@Entity
public class PhoneConsumer extends Consumer {
private String callPlane;
public String getCallPlane() {
return callPlane;
}
public void setCallPlane(String callPlane) {
this.callPlane = callPlane;
}
}
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package com.knowledgewalls.dao;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import com.knowledgewalls.entity.Consumer;
import com.knowledgewalls.entity.InternetConsumer;
import com.knowledgewalls.entity.PhoneConsumer;
@Repository
@Transactional
public class ConsumerDAO {
@PersistenceContext
EntityManager em;
public void saveConsumer(Consumer consumer){
try {
em.persist(consumer);
}
catch(Exception e){
e.printStackTrace();
}
}
public void savePhoneConsumer(PhoneConsumer consumer){
try {
em.persist(consumer);
}
catch(Exception e){
e.printStackTrace();
}
}
public void saveInternetConsumer(InternetConsumer consumer){
try {
em.persist(consumer);
}
catch(Exception e){
e.printStackTrace();
}
}
}
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StudentInfoController.java
package com.knowledgewalls.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import com.knowledgewalls.dao.ConsumerDAO;
import com.knowledgewalls.entity.Consumer;
import com.knowledgewalls.entity.InternetConsumer;
import com.knowledgewalls.entity.PhoneConsumer;
@Controller
public class StudentInfoController {
@Autowired
ConsumerDAO consumerDAO;
@RequestMapping(value="/addConsumers",method=RequestMethod.GET)
public @ResponseBody String addUsers(){
{
Consumer consumer = new Consumer();
consumer.setConsumer_name("Consumer");
consumerDAO.saveConsumer(consumer);
PhoneConsumer phoneConsumer = new PhoneConsumer();
phoneConsumer.setConsumer_name("Phone Consumer");
phoneConsumer.setCallPlane("smarter");
consumerDAO.savePhoneConsumer(phoneConsumer);
InternetConsumer internetConsumer = new InternetConsumer();
internetConsumer.setConsumer_name("Internet Consumer");
internetConsumer.setPackName("fast plus");
consumerDAO.saveInternetConsumer(internetConsumer);
}
return "Consumer saved successfully!";
}
}
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<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" >
<persistence-unit name="hibernatePersistenceUnit">
<properties>
<property name="hibernate.hbm2ddl.auto" value="create" />
</properties>
</persistence-unit>
</persistence>
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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
<context:component-scan base-package="com.knowledgewalls" />
<mvc:annotation-driven />
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="emf" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceXmlLocation" value="classpath*:persistence.xml" />
<property name="persistenceUnitName" value="hibernatePersistenceUnit" />
<property name="dataSource" ref="dataSource"/>
<property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/test" />
<property name="username" value="root" />
<property name="password" value="mysql" />
<property name="initialSize" value="5" />
<property name="maxActive" value="10" />
</bean>
<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="database" value="MYSQL"></property>
<property name="showSql" value="true"></property>
<property name="generateDdl" value="false"></property>
<property name="databasePlatform" value="org.hibernate.dialect.MySQL5InnoDBDialect"></property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="emf" />
</bean>
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>
</beans>
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