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Hibernate - Filters Hibernate - Mappings Hibernate - Inheritance Mapping

Hibernate - Inheritance Mapping (Table Per Subclass)

📌 What You Will Learn

Understand Hibernate - Inheritance Mapping (Table Per Subclass)
See working code examples
Learn from common mistakes and Q&A

Learn Hibernate - Inheritance Mapping (Table Per Subclass) step by step — simple explanations, complete programs with their output, common beginner mistakes, and exam-style MCQs.

Inheritance Mapping (Table Per Subclass) — Account.java

sa.setSbranch("CS");
sa.setSmarks(77);
EmployeeAccount ea = new EmployeeAccount();
ea.setAccNo("a2");
ea.setAccName("BBB");
ea.setAccType("Savings");
ea.setEid("E1");
ea.setEsal(5000);
ea.setEaddr("Hyd");
Transaction tx = session.beginTransaction();
session.save(sa);
session.save(ea);
tx.commit();
System.out.println("Student Account Inserted Successfully");
System.out.println("Employee Account Inserted Successfully");

EXAMPLE:

Example01

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Account {
5	private String accNo;
6	private String accName;
7	private String accType;
8
9	public String getAccNo() {
10	return accNo;
11	}
12	public void setAccNo(String accNo) {
13	this.accNo = accNo;
14	}
15	public String getAccName() {
16	return accName;
17	}
18	public void setAccName(String accName) {
19	this.accName = accName;
20	}
21	public String getAccType() {
22	return accType;
23	}
24	public void setAccType(String accType) {
25	this.accType = accType;
26	}
27
28
29	}
30

Inheritance Mapping (Table Per Subclass) — StudentAccount.java

Example02

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class StudentAccount extends Account{
5	private String sid;
6	private String sbranch;
7	private int smarks;
8
9	public String getSid() {
10	return sid;
11	}
12	public void setSid(String sid) {
13	this.sid = sid;
14	}
15	public String getSbranch() {
16	return sbranch;
17	}
18	public void setSbranch(String sbranch) {
19	this.sbranch = sbranch;
20	}
21	public int getSmarks() {
22	return smarks;
23	}
24	public void setSmarks(int smarks) {
25	this.smarks = smarks;
26	}
27
28
29	}
30

Inheritance Mapping (Table Per Subclass) — EmployeeAccount.java

Example03

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class EmployeeAccount extends Account{
5	private String eid;
6	private float esal;
7	private String eaddr;
8
9	public String getEid() {
10	return eid;
11	}
12	public void setEid(String eid) {
13	this.eid = eid;
14	}
15	public float getEsal() {
16	return esal;
17	}
18	public void setEsal(float esal) {
19	this.esal = esal;
20	}
21	public String getEaddr() {
22	return eaddr;
23	}
24	public void setEaddr(String eaddr) {
25	this.eaddr = eaddr;
26	}
27
28	}
29

Inheritance Mapping (Table Per Subclass) — Account.hbm.xml

Example04

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Account" table="account">
8	<id name="accNo" column="ACCNO"/>
9	<discriminator column="TYPE" type="string"/>
10	<property name="accName" column="ACCNAME"/>
11	<property name="accType" column="ACCTYPE"/>
12
13	<subclass name="com.durgasoft.pojo.StudentAccount" discriminator-value="std">
14	<property name="sid" column="SID"/>
15	<property name="sbranch" column="SBRANCH"/>
16	<property name="smarks" column="SMARKS"/>
17	</subclass>
18
19	<subclass name="com.durgasoft.pojo.EmployeeAccount" discriminator-value="emp">
20	<property name="eid" column="EID"/>
21	<property name="esal" column="ESAL"/>
22	<property name="eaddr" column="EADDR"/>
23	</subclass>
24	</class>
25	</hibernate-mapping>
26

Inheritance Mapping (Table Per Subclass) — hibernate.cfg.xml

Example05

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.user">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
13	<property name="show_Sql">true</property>
14	<mapping resource="Account.hbm.xml"/>
15	</session-factory>
16	</hibernate-configuration>
17

Inheritance Mapping (Table Per Subclass) — Test.java

Example06

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.EmployeeAccount;
12	import com.durgasoft.pojo.StudentAccount;
13
14	public class Test {
15
16	public static void main(String[] args)throws Exception {
17	Configuration cfg = new Configuration();
18	cfg.configure();
19	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
20	builder = builder.applySettings(cfg.getProperties());
21	StandardServiceRegistry registry = builder.build();
22	SessionFactory factory = cfg.buildSessionFactory(registry);
23	Session session = factory.openSession();
24
25	StudentAccount sa = new StudentAccount();
26	sa.setAccNo("a1");
27	sa.setAccName("AAA");
28	sa.setAccType("Savings");
29	sa.setSid("S1");
30	sa.setSbranch("CS");
31	sa.setSmarks(77);
32
33	EmployeeAccount ea = new EmployeeAccount();
34	ea.setAccNo("a2");
35	ea.setAccName("BBB");
36	ea.setAccType("Savings");
37	ea.setEid("E1");
38	ea.setEsal(5000);
39	ea.setEaddr("Hyd");
40
41	Transaction tx = session.beginTransaction();
42	session.save(sa);
43	session.save(ea);
44	tx.commit();
45	System.out.println("Student Account Inserted Successfully");
46	System.out.println("Employee Account Inserted Successfully");
47	}
48	}
49

Inheritance Mapping (Table Per Subclass) — Account.java

To represent Table Per Class Inheritance Mapping javax.persistence package has provided the following three Annotations.

1) @Inheritance 2) @DiscriminatorColumn 3) @DiscriminatorValue

1) @Inheritance

 This annotation is able to specify Inheritance Mapping strategy. @Inheritance(strategy=value) Where value may be SINGLE_TABLE constant from InheritanceType enum.

EX: @INheritance(strategy=InheritanceType.SINGLE_TABLE)

2) @DiscriminatorColumn  This annotation is able to represent Discriminator Column. @DiscriminatorColumn(name ="--") Where "name" is able to take discriminator column name.

EX: @DiscriminatorColumn(name="TYPE")

Note: The above two annotations must be used at super class. 3) @DiscriminatorValue

 It able to provide value to the discriminator column, it must be specified at sub class

Example:

Example07

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.DiscriminatorColumn;
6	import javax.persistence.Entity;
7	import javax.persistence.Id;
8	import javax.persistence.Inheritance;
9	import javax.persistence.InheritanceType;
10	import javax.persistence.Table;
11
12	@Entity
13	@Table(name="account")
14	@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
15	@DiscriminatorColumn(name="TYPE")
16	public class Account {
17	@Id
18	@Column(name="ACCNO")
19	private String accNo;
20	@Column(name="ACCNAME")
21	private String accName;
22	@Column(name="ACCTYPE")
23	private String accType;
24
25	public String getAccNo() {
26	return accNo;
27	}
28	public void setAccNo(String accNo) {
29	this.accNo = accNo;
30	}
31	public String getAccName() {
32	return accName;
33	}
34	public void setAccName(String accName) {
35	this.accName = accName;
36	}
37	public String getAccType() {
38	return accType;
39	}
40	public void setAccType(String accType) {
41	this.accType = accType;
42	}
43
44
45	}
46

Inheritance Mapping (Table Per Subclass) — StudentAccount.java

Example08

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.DiscriminatorValue;
6	import javax.persistence.Entity;
7
8	@Entity
9	@DiscriminatorValue("std")
10	public class StudentAccount extends Account{
11	@Column(name="SID")
12	private String sid;
13	@Column(name="SBRANCH")
14	private String sbranch;
15	@Column(name="SMARKS")
16	private int smarks;
17
18	public String getSid() {
19	return sid;
20	}
21	public void setSid(String sid) {
22	this.sid = sid;
23	}
24	public String getSbranch() {
25	return sbranch;
26	}
27	public void setSbranch(String sbranch) {
28	this.sbranch = sbranch;
29	}
30	public int getSmarks() {
31	return smarks;
32	}
33	public void setSmarks(int smarks) {
34	this.smarks = smarks;
35	}
36
37
38	}
39

Inheritance Mapping (Table Per Subclass) — EmployeeAccount.java

Example09

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.DiscriminatorValue;
6	import javax.persistence.Entity;
7
8	@Entity
9	@DiscriminatorValue("emp")
10	public class EmployeeAccount extends Account{
11	@Column(name="EID")
12	private String eid;
13	@Column(name="ESAL")
14	private float esal;
15	@Column(name="EADDR")
16	private String eaddr;
17
18	public String getEid() {
19	return eid;
20	}
21	public void setEid(String eid) {
22	this.eid = eid;
23	}
24	public float getEsal() {
25	return esal;
26	}
27	public void setEsal(float esal) {
28	this.esal = esal;
29	}
30	public String getEaddr() {
31	return eaddr;
32	}
33	public void setEaddr(String eaddr) {
34	this.eaddr = eaddr;
35	}
36
37
38	}
39

Inheritance Mapping (Table Per Subclass) — hibernate.cfg.xml

Example10

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.user">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
13	<property name="show_Sql">true</property>
14	<mapping class="com.durgasoft.pojo.StudentAccount"/>
15	<mapping class="com.durgasoft.pojo.EmployeeAccount"/>
16	</session-factory>
17	</hibernate-configuration>
18

Inheritance Mapping (Table Per Subclass) — Test.java

Example11

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.Account;
12	import com.durgasoft.pojo.EmployeeAccount;
13	import com.durgasoft.pojo.StudentAccount;
14
15	public class Test {
16
17	public static void main(String[] args)throws Exception {
18	Configuration cfg = new Configuration();
19	cfg.configure();
20	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
21	builder = builder.applySettings(cfg.getProperties());
22	StandardServiceRegistry registry = builder.build();
23	SessionFactory factory = cfg.buildSessionFactory(registry);
24	Session session = factory.openSession();
25
26	StudentAccount sa = (StudentAccount)session.get(Account.class, "a1");
27	System.out.println("Student Account Details");
28	System.out.println("------------------------------");
29	System.out.println("Account Number :"+sa.getAccNo());
30	System.out.println("Account Name :"+sa.getAccName());
31	System.out.println("Account Type :"+sa.getAccType());
32	System.out.println("Student Id :"+sa.getSid());
33	System.out.println("Student Branch :"+sa.getSbranch());
34	System.out.println("Student Marks :"+sa.getSmarks());
35
36	EmployeeAccount ea = (EmployeeAccount)session.get(Account.class, "a2");
37	System.out.println("Employee Account Details");
38	System.out.println("------------------------------");
39	System.out.println("Account Number :"+ea.getAccNo());
40	System.out.println("Account Name :"+ea.getAccName());
41	System.out.println("Account Type :"+ea.getAccType());
42	System.out.println("EmployeeId :"+ea.getEid());
43	System.out.println("EmployeeSalary :"+ea.getEsal());
44	System.out.println("Employee Address :"+ea.getEaddr());
45
46	session.close();
47	factory.close();
48
49	}
50
51	}
52

Table Per Sub class — Payment.java

 In case of "Table Per Subclass" inheritance mapping, we have to prepare a seperate table for each and every class[for both super class and sub classses] existed in inheritance.

 While preparing tables for sub classes we have to provide a join column which must be primary key in super class respective table and in sub class respectiove tables.

 In hibernate applications, if we store sub class objects in database then Hibernate software has to recognize and store super class properties data in super class respective table and sub class respective data in sub class respectgive tables.  To achieve this requirement, Hibernate software has to recognize super class properties

and sub class properties seperately, for this we have to provide sub classes configuration seperatly in hibernate mapping file.  To provide "Table Per Subclass" inheritance mapping we have to use the following xml tags in mapping file.

<hibernate-mapping>
<class name="--" table="--"
<joined-subclass name="--" table="--">
<key column="--"/>
</join-subclass>
</class>
</hibernate-mapping>

 Where "<joined-subclass>" tag is able to configure sub class, where "name" attribute will take fully qualified name of the respective sub class and "table" attribute will take sub class respective table name.

 Where "<key>" tag is able to take join key which is available in sub class respective table.

Example:

Example12

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Payment {
5	private String tx_Id;
6	private String payment_Date;
7	private long payment_Amt;
8
9	public String getTx_Id() {
10	return tx_Id;
11	}
12	public void setTx_Id(String tx_Id) {
13	this.tx_Id = tx_Id;
14	}
15	public String getPayment_Date() {
16	return payment_Date;
17	}
18	public void setPayment_Date(String payment_Date) {
19	this.payment_Date = payment_Date;
20	}
21	public long getPayment_Amt() {
22	return payment_Amt;
23	}
24	public void setPayment_Amt(long payment_Amt) {
25	this.payment_Amt = payment_Amt;
26	}
27
28
29	}
30

Table Per Sub class — CardPayment.java

Example13

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class CardPayment extends Payment {
5	private int card_No;
6	private String expr_Date;
7
8	public int getCard_No() {
9	return card_No;
10	}
11	public void setCard_No(int card_No) {
12	this.card_No = card_No;
13	}
14	public String getExpr_Date() {
15	return expr_Date;
16	}
17	public void setExpr_Date(String expr_Date) {
18	this.expr_Date = expr_Date;
19	}
20
21
22	}
23

Table Per Sub class — ChequePayment.java

Example14

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class ChequePayment extends Payment {
5	private int cheque_No;
6	private String accNo;
7
8	public int getCheque_No() {
9	return cheque_No;
10	}
11	public void setCheque_No(int cheque_No) {
12	this.cheque_No = cheque_No;
13	}
14	public String getAccNo() {
15	return accNo;
16	}
17	public void setAccNo(String accNo) {
18	this.accNo = accNo;
19	}
20
21
22	}
23

Table Per Sub class — payment.hbm.xml

Example15

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Payment" table="payment">
8	<id name="tx_Id" column="TX_ID"/>
9	<property name="payment_Date" column="PAY_DATE"/>
10	<property name="payment_Amt" column="PAY_AMT"/>
11
12	<joined-subclass name="com.durgasoft.pojo.CardPayment" table="card_payment">
13	<key column="TX_ID"/>
14	<property name="card_No" column="CARD_NO"/>
15	<property name="expr_Date" column="EXPR_DATE"/>
16	</joined-subclass>
17	<joined-subclass name="com.durgasoft.pojo.ChequePayment" table="cheque_payment">
18	<key column="TX_ID"/>
19	<property name="cheque_No" column="CHEQUE_NO"/>
20	<property name="accNo" column="ACC_NO"/>
21	</joined-subclass>
22	</class>
23	</hibernate-mapping>
24

Table Per Sub class — hibernate.cfg.xml

Example16

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.user">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
13	<property name="show_Sql">true</property>
14	<mapping resource="payment.hbm.xml"/>
15	</session-factory>
16	</hibernate-configuration>
17

Table Per Sub class — Test.java

Example17

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.CardPayment;
12	import com.durgasoft.pojo.ChequePayment;
13
14	public class Test {
15
16	public static void main(String[] args)throws Exception {
17	Configuration cfg = new Configuration();
18	cfg.configure();
19	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
20	builder = builder.applySettings(cfg.getProperties());
21	StandardServiceRegistry registry = builder.build();
22	SessionFactory factory = cfg.buildSessionFactory(registry);
23	Session session = factory.openSession();
24
25	CardPayment card_Payment = new CardPayment();
26	card_Payment.setTx_Id("t111");
27	card_Payment.setPayment_Date("16/3/18");
28	card_Payment.setPayment_Amt(5000);
29	card_Payment.setCard_No(1234);
30	card_Payment.setExpr_Date("12/12/20");
31
32	ChequePayment cheque_Payment = new ChequePayment();
33	cheque_Payment.setTx_Id("t222");
34	cheque_Payment.setPayment_Date("17/3/18");
35	cheque_Payment.setPayment_Amt(7000);
36	cheque_Payment.setCheque_No(2345);
37	cheque_Payment.setAccNo("a222");
38
39	Transaction tx = session.beginTransaction();
40	session.save(card_Payment);
41	session.save(cheque_Payment);
42	tx.commit();
43	System.out.println("Card Payment Stored Successfully");
44	System.out.println("Cheque Payment Stored Successfully");
45	}
46	}
47

Table Per Sub class — Payment.java

Note: The above application required the followeing database

SQL> desc payment;

Name Null? Type

TX_ID NOT NULL VARCHAR2(5)

PAY_DATE VARCHAR2(10)

PAY_AMT

SQL> desc card_payment;

Name Null? Type

TX_ID NOT NULL VARCHAR2(5)

CARD_NO NUMBER(8)

EXPR_DATE VARCHAR2(10)

SQL> desc cheque_payment;

Name Null? Type

TX_ID NOT NULL VARCHAR2(5)

CHEQUE_NO NUMBER(8)

ACC_NO VARCHAR2(10)

SQL>

To represent "Table Per Subclass" inheritance mapping mechanism, javax.persistence package has provided the following Annotations

1) @Inheritance 2) @PrimaryKeyJoinColumn

1) @Inheritance

 This annotation is able to represent a particular Inheritance mapping mechanism,it will use "strategy" member to take a particular inheritance mapping, where "strategy" attribvute will take "JOINED" value constant from "InheritanceType" enum.

EX: @Inheritance(strategy=IOnheritanceType.JOINED) 2) @PrimaryKeyJoinColumn

 This annotation will be used at sub classes inorder to provide Join Key column name. It will use "name" attribute to provide "join key column".

EX: @PrimaryKeyJoinColumn(name="TX_ID")

Example:

Example18

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Id;
7	import javax.persistence.Inheritance;
8	import javax.persistence.InheritanceType;
9	import javax.persistence.Table;
10
11	@Entity
12	@Table(name="payment")
13	@Inheritance(strategy=InheritanceType.JOINED)
14	public class Payment {
15	@Id
16	@Column(name="TX_ID")
17	private String tx_Id;
18	@Column(name="PAY_DATE")
19	private String payment_Date;
20	@Column(name="PAY_AMT")
21	private long payment_Amt;
22
23	public String getTx_Id() {
24	return tx_Id;
25	}
26	public void setTx_Id(String tx_Id) {
27	this.tx_Id = tx_Id;
28	}
29	public String getPayment_Date() {
30	return payment_Date;
31	}
32	public void setPayment_Date(String payment_Date) {
33	this.payment_Date = payment_Date;
34	}
35	public long getPayment_Amt() {
36	return payment_Amt;
37	}
38	public void setPayment_Amt(long payment_Amt) {
39	this.payment_Amt = payment_Amt;
40	}
41	}
42

Table Per Sub class — CardPayment.java

Example19

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.PrimaryKeyJoinColumn;
7	import javax.persistence.Table;
8
9	@Entity
10	@Table(name="card_payment")
11	@PrimaryKeyJoinColumn(name="TX_ID")
12	public class CardPayment extends Payment {
13	@Column(name="CARD_NO")
14	private int card_No;
15	@Column(name="EXPR_DATE")
16	private String expr_Date;
17
18	public int getCard_No() {
19	return card_No;
20	}
21	public void setCard_No(int card_No) {
22	this.card_No = card_No;
23	}
24	public String getExpr_Date() {
25	return expr_Date;
26	}
27	public void setExpr_Date(String expr_Date) {
28	this.expr_Date = expr_Date;
29	}
30
31
32	}
33

Table Per Sub class — ChequePayment.java

Example20

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.PrimaryKeyJoinColumn;
7	import javax.persistence.Table;
8
9	@Entity
10	@Table(name="cheque_payment")
11	@PrimaryKeyJoinColumn(name="TX_ID")
12	public class ChequePayment extends Payment {
13	@Column(name="CHEQUE_NO")
14	private int cheque_No;
15	@Column(name="ACC_NO")
16	private String accNo;
17
18	public int getCheque_No() {
19	return cheque_No;
20	}
21	public void setCheque_No(int cheque_No) {
22	this.cheque_No = cheque_No;
23	}
24	public String getAccNo() {
25	return accNo;
26	}
27	public void setAccNo(String accNo) {
28	this.accNo = accNo;
29	}
30
31
32	}
33

Table Per Sub class — hibernate.cfg.xml

Example21

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.user">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
13	<property name="show_Sql">true</property>
14	<mapping class="com.durgasoft.pojo.Payment"/>
15	<mapping class="com.durgasoft.pojo.CardPayment"/>
16	<mapping class="com.durgasoft.pojo.ChequePayment"/>
17	</session-factory>
18	</hibernate-configuration>
19

Table Per Sub class — Test.java

Example22

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.CardPayment;
12	import com.durgasoft.pojo.ChequePayment;
13	import com.durgasoft.pojo.Payment;
14
15	public class Test {
16
17	public static void main(String[] args)throws Exception {
18	Configuration cfg = new Configuration();
19	cfg.configure();
20	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
21	builder = builder.applySettings(cfg.getProperties());
22	StandardServiceRegistry registry = builder.build();
23	SessionFactory factory = cfg.buildSessionFactory(registry);
24	Session session = factory.openSession();
25
26	CardPayment card_Payment = (CardPayment)session.get(Payment.class, "t111");
27	System.out.println("CardPayment Details");
28	System.out.println("---------------------------");
29	System.out.println("Transaction ID :"+card_Payment.getTx_Id());
30	System.out.println("Payment Date :"+card_Payment.getPayment_Date());
31	System.out.println("Payment Amount :"+card_Payment.getPayment_Amt());
32	System.out.println("Card Number :"+card_Payment.getCard_No());
33	System.out.println("Expr Date :"+card_Payment.getExpr_Date());
34	System.out.println();
35
36	ChequePayment cheque_Payment = (ChequePayment)session.get(Payment.class, "t222");
37	System.out.println("ChequePayment Details");
38	System.out.println("---------------------------");
39	System.out.println("Transaction ID :"+cheque_Payment.getTx_Id());
40	System.out.println("Payment Date :"+cheque_Payment.getPayment_Date());
41	System.out.println("Payment Amount :"+cheque_Payment.getPayment_Amt());
42	System.out.println("Cheque Number :"+cheque_Payment.getCheque_No());
43	System.out.println("Account Number :"+cheque_Payment.getAccNo());
44
45
46	}
47	}
48

Table Per Concreate Class — Person.java

In "Table per Concreate Class" inheritance mapping , we will prepare a seperate table for each and every sub class containing the columns representing both the super class properties and the respective sub class properties.

In the above context, if we save any sub class object then Hibernate software has to distribute sub class objects data in the respective table and in the respective columns. To achieve this we have to use the following xml tags in hibernate mapping file.

<hibernate-mapping>
<class name="--">
<union-subclass name="--" table="--">
<property name="--" column="--"/>
</union-subclass>
</class>
</hibernate-mapping>

Where "<union-subclass> tag is able to provide mapping between a particular sub class and the respective table, where "name" attribute will take sub class name and table attribute will take the respective table name.

Example:

Example23

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Person {
5	private String pname;
6	private String paddr;
7
8	public String getPname() {
9	return pname;
10	}
11	public void setPname(String pname) {
12	this.pname = pname;
13	}
14	public String getPaddr() {
15	return paddr;
16	}
17	public void setPaddr(String paddr) {
18	this.paddr = paddr;
19	}
20
21
22	}
23

Table Per Concreate Class — Employee.java

Example24

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Employee extends Person {
5	private String eid;
6	private float esal;
7
8	public String getEid() {
9	return eid;
10	}
11	public void setEid(String eid) {
12	this.eid = eid;
13	}
14	public float getEsal() {
15	return esal;
16	}
17	public void setEsal(float esal) {
18	this.esal = esal;
19	}
20
21
22	}
23

Table Per Concreate Class — Customer.java

Example25

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Customer extends Person {
5	private String cid;
6	private String cmobile;
7
8	public String getCid() {
9	return cid;
10	}
11	public void setCid(String cid) {
12	this.cid = cid;
13	}
14	public String getCmobile() {
15	return cmobile;
16	}
17	public void setCmobile(String cmobile) {
18	this.cmobile = cmobile;
19	}
20
21
22	}
23

Table Per Concreate Class — Person.hbm.xml

Example26

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Person">
8	<id name="pname" column="PNAME"/>
9	<property name="paddr" column="PADDR"/>
10	<union-subclass name="com.durgasoft.pojo.Employee" table="employee">
11	<property name="eid" column="EID"/>
12	<property name="esal" column="ESAL"/>
13	</union-subclass>
14	<union-subclass name="com.durgasoft.pojo.Customer" table="customer">
15	<property name="cid" column="CID"/>
16	<property name="cmobile" column="CMOBILE"/>
17	</union-subclass>
18	</class>
19	</hibernate-mapping>
20

Table Per Concreate Class — hibernate.cfg.xml

Example27

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.user">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
13	<property name="show_Sql">true</property>
14	<mapping resource="Person.hbm.xml"/>
15	</session-factory>
16	</hibernate-configuration>
17

Table Per Concreate Class — Test.java

Example28

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11
12	import com.durgasoft.pojo.Customer;
13	import com.durgasoft.pojo.Employee;
14
15	public class Test {
16
17	public static void main(String[] args)throws Exception {
18	Configuration cfg = new Configuration();
19	cfg.configure();
20	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
21	builder = builder.applySettings(cfg.getProperties());
22	StandardServiceRegistry registry = builder.build();
23	SessionFactory factory = cfg.buildSessionFactory(registry);
24	Session session = factory.openSession();
25
26	Employee emp = new Employee();
27	emp.setPname("AAA");
28	emp.setPaddr("Hyd");
29	emp.setEid("E-111");
30	emp.setEsal(5000);
31
32	Customer cust = new Customer();
33	cust.setPname("BBB");
34	cust.setPaddr("Hyd");
35	cust.setCid("C-111");
36	cust.setCmobile("91-9988776655");
37
38	Transaction tx = session.beginTransaction();
39	session.save(emp);
40	session.save(cust);
41	tx.commit();
42	System.out.println("Employee Object Inserted Successfully");
43	System.out.println("Customer Object Inserted Successfully");
44
45	session.close();
46	factory.close();
47
48	}
49
50	}
51

Database — Person.java

SQL> create table employee (PNAME varchar2(10) primary key, PADDR varchar2(10), EID varchar2(5), ESAL float); SQL> commit; SQL> create table customer(PNAME varchar2(10) primary key, PADDR varchar2(10), CID varchar2(5), CMOBILE varchar2(20)); SQL> commit;

To represent this inheritance mapping mechanism we have to use @Inheritance() annotation , where we have to use "TABLE_PER_CLASS" constant from INheritanceType enum as value to 'strategy' member.

@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)

Example:

Example29

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Id;
7	import javax.persistence.Inheritance;
8	import javax.persistence.InheritanceType;
9
10	@Entity
11	@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
12	public class Person {
13	@Id
14	@Column(name="PNAME")
15	private String pname;
16	@Column(name="PADDR")
17	private String paddr;
18
19	public String getPname() {
20	return pname;
21	}
22	public void setPname(String pname) {
23	this.pname = pname;
24	}
25	public String getPaddr() {
26	return paddr;
27	}
28	public void setPaddr(String paddr) {
29	this.paddr = paddr;
30	}
31
32
33	}
34

Database — Employee.java

Example30

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Table;
7
8	@Entity
9	@Table(name="employee")
10	public class Employee extends Person {
11	@Column(name="EID")
12	private String eid;
13	@Column(name="ESAL")
14	private float esal;
15
16	public String getEid() {
17	return eid;
18	}
19	public void setEid(String eid) {
20	this.eid = eid;
21	}
22	public float getEsal() {
23	return esal;
24	}
25	public void setEsal(float esal) {
26	this.esal = esal;
27	}
28
29
30	}
31

Database — Customer.java

Example31

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Table;
7
8	@Entity
9	@Table(name="customer")
10	public class Customer extends Person {
11	@Column(name="CID")
12	private String cid;
13	@Column(name="CMOBILE")
14	private String cmobile;
15
16	public String getCid() {
17	return cid;
18	}
19	public void setCid(String cid) {
20	this.cid = cid;
21	}
22	public String getCmobile() {
23	return cmobile;
24	}
25	public void setCmobile(String cmobile) {
26	this.cmobile = cmobile;
27	}
28
29
30	}
31

Database — hibernate.cfg.xml

Example32

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.user">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
13	<property name="show_Sql">true</property>
14	<!-- <mapping resource="Person.hbm.xml"/> -->
15	<mapping class="com.durgasoft.pojo.Person"/>
16	<mapping class="com.durgasoft.pojo.Employee"/>
17	<mapping class="com.durgasoft.pojo.Customer"/>
18	</session-factory>
19	</hibernate-configuration>
20

Database — Test.java

Example33

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10	import com.durgasoft.pojo.Customer;
11	import com.durgasoft.pojo.Employee;
12
13	public class Test {
14
15	public static void main(String[] args)throws Exception {
16	Configuration cfg = new Configuration();
17	cfg.configure();
18	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
19	builder = builder.applySettings(cfg.getProperties());
20	StandardServiceRegistry registry = builder.build();
21	SessionFactory factory = cfg.buildSessionFactory(registry);
22	Session session = factory.openSession();
23
24	Employee emp = (Employee)session.get(Employee.class, "AAA");
25	Customer cust = (Customer)session.get(Customer.class, "BBB");
26
27	System.out.println("Employee Details");
28	System.out.println("-----------------------");
29	System.out.println("Person Name :"+emp.getPname());
30	System.out.println("Person Address :"+emp.getPaddr());
31	System.out.println("Employee Id :"+emp.getEid());
32	System.out.println("Employee Salary:"+emp.getEsal());
33	System.out.println();
34	System.out.println("Customer Details");
35	System.out.println("-----------------------");
36	System.out.println("Person Name :"+cust.getPname());
37	System.out.println("Person Address :"+cust.getPaddr());
38	System.out.println("Customer Id :"+cust.getCid());
39	System.out.println("Customer Mobile:"+cust.getCmobile());
40	session.close();
41	factory.close();
42
43	}
44
45	}
46

Association Mapping

In General, in Enterprise applications we will use both Object Oriented Data Model and Relational Data Model to represent data. In Enterprise applications we will use Object Oriented Data Model in Front-End applications toreprepsent data and we will used Relational data Model in Back-End Applications to represent Data.

In the above context, both the data models are having their own approaches to represent data, the differences between data models may provide mismatches between data models, it may reduce data persistency in Enterprise Applications.

In the above context, to improve data persistency we must use ORM implementations, Hibernate is an ORM implementation , it able to provide solutions for mismatchs between Data models. In Enterprise applications, we are able to get Associations mismatch while achieving associations in Object Oriented Data Model and in Relational Data Model.

IN Enterprise Applications, the main intention of Associations is to to improve data navigation between entities and to improve communication between entities.

In Object Oriented Data Model, we are able to achieve associations by declaring one or Collection of reference variables of an entity class in another entity class.

Example34

JCode Cell

1
2	class Account{
3	}
4	class Address{
5	}
6
7	class Employee{
8	-----
9	Account acc;// one-to-one association
10	-----
11	Collection<Address> addr; //one-to-many
12	-----
13	}
14

Association Mapping

In relational Data Model, we are able to achieve associations in the following three ways.

1) By defining Primary Key-Foreign Key relations between tables 2) By Providing Join column between tables 3) By Defining Join table between tables.

To resolve the above associations mismatch between both the data models Hibernate has provided "Association Mappings".

Hibernate has provided the following four types of Associations mappings inorder to resolve Associations mismatch.

One-To-One Association Mapping
One-To-Many Association Mapping
Many-To-One Association Mapping
Many-To-Many Association Mapping

One-To-One Association Mapping — Employee.java

It is a relation between entities, where one instance of an entity should be mapped with exactly one instance of another entity. EX: Every Employee must have exactly one individual Account.

In Hibernate applications, to achieve One-To-One Associations, we have to use the following tag in mapping file.

<one-to-one name="--" class="--" cascade="--"/>

 Where "name" attribute take property name of the entity class.  Where "class" attribute will take Fully qualified name of the associated class.  Where "cascade" attribute will take the values like all, none, insert, update and delete

inorder to perform operations in cascading style, that is, if we delete employee table automatically Account table must also be deleted.

Example:

Example36

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Employee {
5	private String eid;
6	private String ename;
7	private float esal;
8	private String eaddr;
9	private Account acc;
10
11	public Account getAcc() {
12	return acc;
13	}
14	public void setAcc(Account acc) {
15	this.acc = acc;
16	}
17	public String getEid() {
18	return eid;
19	}
20	public void setEid(String eid) {
21	this.eid = eid;
22	}
23	public String getEname() {
24	return ename;
25	}
26	public void setEname(String ename) {
27	this.ename = ename;
28	}
29	public float getEsal() {
30	return esal;
31	}
32	public void setEsal(float esal) {
33	this.esal = esal;
34	}
35	public String getEaddr() {
36	return eaddr;
37	}
38	public void setEaddr(String eaddr) {
39	this.eaddr = eaddr;
40	}
41
42	}
43

One-To-One Association Mapping — Account.java

Example37

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Account {
5	private String accNo;
6	private String accName;
7	private String accType;
8
9	public String getAccNo() {
10	return accNo;
11	}
12	public void setAccNo(String accNo) {
13	this.accNo = accNo;
14	}
15	public String getAccName() {
16	return accName;
17	}
18	public void setAccName(String accName) {
19	this.accName = accName;
20	}
21	public String getAccType() {
22	return accType;
23	}
24	public void setAccType(String accType) {
25	this.accType = accType;
26	}
27
28	}
29

One-To-One Association Mapping — Employee.hbm.xml

Example38

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Employee" table="emp1">
8	<id name="eid" column="EID" length="5"/>
9	<property name="ename" column="ENAME" length="10"/>
10	<property name="esal" column="ESAL" length="10"/>
11	<property name="eaddr" column="EADDR" length="10"/>
12	<one-to-one name="acc" class="com.durgasoft.pojo.Account" cascade="all"/>
13	</class>
14	</hibernate-mapping>
15

One-To-One Association Mapping — Account.hbm.xml

Example39

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Account" table="account">
8	<id name="accNo" column="ACCNO" length="10"/>
9	<property name="accName" column="ACCNAME" length="10"/>
10	<property name="accType" column="ACCTYPE" length="10"/>
11	</class>
12	</hibernate-mapping>
13

One-To-One Association Mapping — hibernate.cfg.xml

Example40

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.username">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.hbm2ddl.auto">create</property>
13	<property name="hibernate.dialect">org.hibernate.dialect.OracleDialect</property>
14	<mapping resource="Employee.hbm.xml"/>
15	<mapping resource="Account.hbm.xml"/>
16	</session-factory>
17	</hibernate-configuration>
18

One-To-One Association Mapping — Test.java

Example41

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.Account;
12	import com.durgasoft.pojo.Employee;
13
14	public class Test {
15
16	public static void main(String[] args)throws Exception {
17	Configuration cfg = new Configuration();
18	cfg.configure();
19	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
20	builder = builder.applySettings(cfg.getProperties());
21	StandardServiceRegistry registry = builder.build();
22	SessionFactory sessionFactory = cfg.buildSessionFactory(registry);
23
24	Session session = sessionFactory.openSession();
25
26	Account acc = new Account();
27	acc.setAccNo("abc123");
28	acc.setAccName("Durga");
29	acc.setAccType("Savings");
30
31	Employee emp = new Employee();
32	emp.setEid("E-111");
33	emp.setEname("Durga");
34	emp.setEsal(25000);
35	emp.setEaddr("Hyd");
36	emp.setAcc(acc);
37
38	Transaction tx = session.beginTransaction();
39	session.save(emp);
40	tx.commit();
41	System.out.println("Employee Inserted Successfully");
42	session.close();
43	sessionFactory.close();
44
45	}
46
47	}
48

One-To-One Association Mapping — Employee.java

In Hibernate Applications , to represent one-to-one association JPA has provided the following annotation as part of javax.persistence package.

@OneToOne(cascade=Val) Where val may be the constants like ALL, DETACH, MERGE, REFREESH, REMOVE, PERSIST from CascadeType enum.

The above annotation must be provided just before the entity reference variable in container entity or just above of the getXXX() method w.r.t the entity reference variable.

EX:

Example42

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.CascadeType;
5	import javax.persistence.Column;
6	import javax.persistence.Entity;
7	import javax.persistence.Id;
8	import javax.persistence.OneToOne;
9	import javax.persistence.Table;
10
11	@Entity
12	@Table(name="emp1")
13	public class Employee {
14	@Id
15	@Column(name="EID", length=5)
16	private String eid;
17	@Column(name="ENAME", length=10)
18	private String ename;
19	@Column(name="ESAL", length=6)
20	private float esal;
21	@Column(name="EADDR", length=10)
22	private String eaddr;
23	@OneToOne(cascade=CascadeType.ALL)
24	private Account acc;
25
26	public Account getAcc() {
27	return acc;
28	}
29	public void setAcc(Account acc) {
30	this.acc = acc;
31	}
32	public String getEid() {
33	return eid;
34	}
35	public void setEid(String eid) {
36	this.eid = eid;
37	}
38	public String getEname() {
39	return ename;
40	}
41	public void setEname(String ename) {
42	this.ename = ename;
43	}
44	public float getEsal() {
45	return esal;
46	}
47	public void setEsal(float esal) {
48	this.esal = esal;
49	}
50	public String getEaddr() {
51	return eaddr;
52	}
53	public void setEaddr(String eaddr) {
54	this.eaddr = eaddr;
55	}
56
57	}
58

One-To-One Association Mapping — Account.java

Example43

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Id;
7	import javax.persistence.Table;
8
9	@Entity
10	@Table(name="account")
11	public class Account {
12	@Id
13	@Column(name="ACCNO", length=10)
14	private String accNo;
15	@Column(name="ACCNAME", length=10)
16	private String accName;
17	@Column(name="ACCTYPE", length=10)
18	private String accType;
19
20	public String getAccNo() {
21	return accNo;
22	}
23	public void setAccNo(String accNo) {
24	this.accNo = accNo;
25	}
26	public String getAccName() {
27	return accName;
28	}
29	public void setAccName(String accName) {
30	this.accName = accName;
31	}
32	public String getAccType() {
33	return accType;
34	}
35	public void setAccType(String accType) {
36	this.accType = accType;
37	}
38
39	}
40

One-To-One Association Mapping — hibernate.cfg.xml

Example44

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.username">system</property>
11	<property name="connection.password">durga</property>
12	<!-- <property name="hibernate.hbm2ddl.auto">create</property> -->
13	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
14	<property name="show_sql">true</property>
15	<mapping class="com.durgasoft.pojo.Employee"/>
16	<mapping class="com.durgasoft.pojo.Account"/>
17	</session-factory>
18	</hibernate-configuration>
19

One-To-One Association Mapping — Test.java

Example45

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.Account;
12	import com.durgasoft.pojo.Employee;
13
14	public class Test {
15
16	public static void main(String[] args)throws Exception {
17	Configuration cfg = new Configuration();
18	cfg.configure();
19	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
20	builder = builder.applySettings(cfg.getProperties());
21	StandardServiceRegistry registry = builder.build();
22	SessionFactory sessionFactory = cfg.buildSessionFactory(registry);
23
24	Session session = sessionFactory.openSession();
25	/*
26	Account acc = new Account();
27	acc.setAccNo("abc123");
28	acc.setAccName("Durga");
29	acc.setAccType("Savings");
30
31	Employee emp = new Employee();
32	emp.setEid("E-111");
33	emp.setEname("Durga");
34	emp.setEsal(25000);
35	emp.setEaddr("Hyd");
36	emp.setAcc(acc);
37
38	Transaction tx = session.beginTransaction();
39	session.save(emp);
40	tx.commit();
41	System.out.println("Employee Inserted Successfully");
42	*/
43	Employee emp = (Employee)session.get("com.durgasoft.pojo.Employee", "E-111");
44	System.out.println("Employee Details");
45	System.out.println("------------------------");
46	System.out.println("Employee Id :"+emp.getEid());
47	System.out.println("Employee Name :"+emp.getEname());
48	System.out.println("Employee Salary :"+emp.getEsal());
49	System.out.println("Employee Address :"+emp.getEaddr());
50
51	Account acc = emp.getAcc();
52	System.out.println(acc);
53	System.out.println("Account Details");
54	System.out.println("---------------------");
55	System.out.println("Account Number :"+acc.getAccNo());
56	System.out.println("Account Name :"+acc.getAccName());
57	System.out.println("Account Type :"+acc.getAccType());
58
59	session.close();
60	sessionFactory.close();
61
62	}
63	}
64

One-To-Many Association — Employee.java

It is a relation between entities where one instance of an entity should be mapped with multiple instances of another entity.

EX: Single Department has Multiple Employees

In Hibernate applications, to represent One-To-Many association we have to use the following tags in mapping files.

<hibernate-mapping>
<class name="--" table="--">
<set name="---" cascade="--">
<key column="---"/>
<one-to-many class="---"/>
</set>
</class>
</hibernate-mapping>

 Where <set> tag is able to represent Collection object, that is, many side in one-to-many and in many-to-many.

 Where "name" attribute is representing property name which is representing Collection.  Where "cascade" attribute will take cascade values like all, insert,....  Where <key> tag can be used to specify Join key configuration.  Where "column" attribute in <key> tag is able to join column name.  Where "<one-to-many>" tag is able to represent one-To-many association.  Where "class" attribute in <one-to-many> tag will take class name that is contained class.

Example:

Example46

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Employee {
5	private String eid;
6	private String ename;
7	private float esal;
8	private String eaddr;
9
10	public Employee(String eid, String ename, float esal, String eaddr) {
11	this.eid = eid;
12	this.ename = ename;
13	this.esal = esal;
14	this.eaddr = eaddr;
15	}
16
17	public String getEid() {
18	return eid;
19	}
20	public void setEid(String eid) {
21	this.eid = eid;
22	}
23	public String getEname() {
24	return ename;
25	}
26	public void setEname(String ename) {
27	this.ename = ename;
28	}
29	public float getEsal() {
30	return esal;
31	}
32	public void setEsal(float esal) {
33	this.esal = esal;
34	}
35	public String getEaddr() {
36	return eaddr;
37	}
38	public void setEaddr(String eaddr) {
39	this.eaddr = eaddr;
40	}
41
42
43	}
44

One-To-Many Association — Department.java

Example47

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import java.util.Set;
5
6	public class Department {
7	private String did;
8	private String dname;
9	private Set<Employee> emps;
10
11	public String getDid() {
12	return did;
13	}
14	public void setDid(String did) {
15	this.did = did;
16	}
17	public String getDname() {
18	return dname;
19	}
20	public void setDname(String dname) {
21	this.dname = dname;
22	}
23	public Set<Employee> getEmps() {
24	return emps;
25	}
26	public void setEmps(Set<Employee> emps) {
27	this.emps = emps;
28	}
29
30
31	}
32

One-To-Many Association — Employee.hbm.xml

Example48

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Employee" table="emp1">
8	<id name="eid" column="EID" length="5"/>
9	<property name="ename" column="ENAME" length="10"/>
10	<property name="esal" column="ESAL" length="10"/>
11	<property name="eaddr" column="EADDR" length="10"/>
12	</class>
13	</hibernate-mapping>
14

One-To-Many Association — Department.hbm.xml

Example49

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Department" table="dept">
8	<id name="did" column="DID" length="5"/>
9	<property name="dname" column="DNAME" length="10"/>
10	<set name="emps" cascade="all">
11	<key column="DID"/>
12	<one-to-many class="com.durgasoft.pojo.Employee"/>
13	</set>
14	</class>
15	</hibernate-mapping>
16

One-To-Many Association — hibernate.cfg.xml

Example50

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.username">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.hbm2ddl.auto">create</property>
13	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
14	<property name="show_sql">true</property>
15	<mapping resource="Employee.hbm.xml"/>
16	<mapping resource="Department.hbm.xml"/>
17	</session-factory>
18	</hibernate-configuration>
19

One-To-Many Association — Test.java

Example51

JCode Cell

1
2	package com.durgasoft.test;
3
4	import java.util.HashSet;
5	import java.util.Set;
6
7	import org.hibernate.Session;
8	import org.hibernate.SessionFactory;
9	import org.hibernate.Transaction;
10	import org.hibernate.boot.registry.StandardServiceRegistry;
11	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
12	import org.hibernate.cfg.Configuration;
13
14	import com.durgasoft.pojo.Department;
15	import com.durgasoft.pojo.Employee;
16
17	public class Test {
18
19	public static void main(String[] args) throws Exception{
20	Configuration config = new Configuration();
21	config.configure();
22	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
23	builder = builder.applySettings(config.getProperties());
24	StandardServiceRegistry registry = builder.build();
25	SessionFactory sessionFactory = config.buildSessionFactory(registry);
26	Session session = sessionFactory.openSession();
27
28	Employee e1 = new Employee("E-111", "AAA", 5000, "Hyd");
29	Employee e2 = new Employee("E-222", "BBB", 6000, "Hyd");
30	Employee e3 = new Employee("E-333", "CCC", 7000, "Hyd");
31	Employee e4 = new Employee("E-444", "DDD", 8000, "Hyd");
32
33	Set<Employee> emps = new HashSet<Employee>();
34	emps.add(e1);
35	emps.add(e2);
36	emps.add(e3);
37	emps.add(e4);
38
39	Department dept = new Department();
40	dept.setDid("D-111");
41	dept.setDname("ADMIN");
42	dept.setEmps(emps);
43
44	Transaction tx = session.beginTransaction();
45	session.save(dept);
46	tx.commit();
47	System.out.println("Department Inserted Successfully");
48	session.close();
49	sessionFactory.close();
50	}
51	}
52

One-To-Many Association — Employee.java

In Hibernate Applications, to represent One-To-Many association , JPA has provided the following annotation.

@OneToMany(cascade=CascadeType.ALL)

EX:

Example52

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Id;
7	import javax.persistence.Table;
8
9	@Entity
10	@Table(name="emp1")
11	public class Employee {
12	@Id
13	@Column(name="EID", length=5)
14	private String eid;
15	@Column(name="ENAME", length=10)
16	private String ename;
17	@Column(name="ESAL", length=5)
18	private float esal;
19	@Column(name="EADDR", length=10)
20	private String eaddr;
21
22	public Employee(String eid, String ename, float esal, String eaddr) {
23	this.eid = eid;
24	this.ename = ename;
25	this.esal = esal;
26	this.eaddr = eaddr;
27	}
28
29	public Employee(){
30
31	}
32
33	public String getEid() {
34	return eid;
35	}
36	public void setEid(String eid) {
37	this.eid = eid;
38	}
39	public String getEname() {
40	return ename;
41	}
42	public void setEname(String ename) {
43	this.ename = ename;
44	}
45	public float getEsal() {
46	return esal;
47	}
48	public void setEsal(float esal) {
49	this.esal = esal;
50	}
51	public String getEaddr() {
52	return eaddr;
53	}
54	public void setEaddr(String eaddr) {
55	this.eaddr = eaddr;
56	}
57
58
59	}
60

One-To-Many Association — Department.java

Example53

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import java.util.Set;
5
6	import javax.persistence.CascadeType;
7	import javax.persistence.Column;
8	import javax.persistence.Entity;
9	import javax.persistence.Id;
10	import javax.persistence.OneToMany;
11	import javax.persistence.Table;
12	@Entity
13	@Table(name="dept")
14	public class Department {
15	@Id
16	@Column(name="DID", length=5)
17	private String did;
18	@Column(name="DNAME", length=10)
19	private String dname;
20	@OneToMany(cascade=CascadeType.ALL)
21	private Set<Employee> emps;
22
23	public String getDid() {
24	return did;
25	}
26	public void setDid(String did) {
27	this.did = did;
28	}
29	public String getDname() {
30	return dname;
31	}
32	public void setDname(String dname) {
33	this.dname = dname;
34	}
35	public Set<Employee> getEmps() {
36	return emps;
37	}
38	public void setEmps(Set<Employee> emps) {
39	this.emps = emps;
40	}
41
42	}
43

One-To-Many Association — hibernate.cfg.xml

Example54

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.username">system</property>
11	<property name="connection.password">durga</property>
12	<!-- <property name="hibernate.hbm2ddl.auto">create</property> -->
13	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
14	<property name="show_sql">true</property>
15	<mapping class="com.durgasoft.pojo.Employee"/>
16	<mapping class="com.durgasoft.pojo.Department"/>
17	</session-factory>
18	</hibernate-configuration>
19

One-To-Many Association — Test.java

Example55

JCode Cell

1
2	package com.durgasoft.test;
3
4	import java.util.HashSet;
5	import java.util.Set;
6
7	import org.hibernate.Session;
8	import org.hibernate.SessionFactory;
9	import org.hibernate.Transaction;
10	import org.hibernate.boot.registry.StandardServiceRegistry;
11	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
12	import org.hibernate.cfg.Configuration;
13
14	import com.durgasoft.pojo.Department;
15	import com.durgasoft.pojo.Employee;
16
17	public class Test {
18
19	public static void main(String[] args) throws Exception{
20	Configuration config = new Configuration();
21	config.configure();
22	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
23	builder = builder.applySettings(config.getProperties());
24	StandardServiceRegistry registry = builder.build();
25	SessionFactory sessionFactory = config.buildSessionFactory(registry);
26	Session session = sessionFactory.openSession();
27	/*
28	Employee e1 = new Employee("E-111", "AAA", 5000, "Hyd");
29	Employee e2 = new Employee("E-222", "BBB", 6000, "Hyd");
30	Employee e3 = new Employee("E-333", "CCC", 7000, "Hyd");
31	Employee e4 = new Employee("E-444", "DDD", 8000, "Hyd");
32
33	Set<Employee> emps = new HashSet<Employee>();
34	emps.add(e1);
35	emps.add(e2);
36	emps.add(e3);
37	emps.add(e4);
38
39	Department dept = new Department();
40	dept.setDid("D-111");
41	dept.setDname("ADMIN");
42	dept.setEmps(emps);
43
44	Transaction tx = session.beginTransaction();
45	session.save(dept);
46	tx.commit();
47	System.out.println("Department Inserted Successfully");
48	*/
49	Department dept = (Department)session.get(Department.class, "D-111");
50	System.out.println("Department Details");
51	System.out.println("-----------------------");
52	System.out.println("Department Id :"+dept.getDid());
53	System.out.println("Department Name :"+dept.getDname());
54	Set<Employee> emps = dept.getEmps();
55	System.out.println("EID\tENAME\tESAL\tEADDR");
56	System.out.println("-----------------------------------");
57	for(Employee emp: emps) {
58	System.out.print(emp.getEid()+"\t");
59	System.out.print(emp.getEname()+"\t");
60	System.out.print(emp.getEsal()+"\t");
61	System.out.print(emp.getEaddr()+"\n");
62	}
63
64	session.close();
65	sessionFactory.close();
66	}
67	}
68

Many-To-One Association

It is a relation between entity classes, where multiple instances of an entity should be mapped with exactly single instance of another entity.

EX: Multiple Students have joined with single branch — Branch.java

To provide Many-To-One Association in Hibernate applications then we have to use the following tag in mapping file.

<many-to-one name="--" class="--" cascade="all"/>

 where "name" attribute will take property name which is representing many to one relation.  where "class" attribute will take contained class name.  where "cascade" attribute will take the values like all, insert,.......

EX:

Example57

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Branch {
5	private String bid;
6	private String bname;
7
8	public String getBid() {
9	return bid;
10	}
11	public void setBid(String bid) {
12	this.bid = bid;
13	}
14	public String getBname() {
15	return bname;
16	}
17	public void setBname(String bname) {
18	this.bname = bname;
19	}
20
21	}
22

EX: Multiple Students have joined with single branch — Student.java

Example58

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Student {
5	private String sid;
6	private String sname;
7	private String saddr;
8	private Branch branch;
9
10	public String getSid() {
11	return sid;
12	}
13	public void setSid(String sid) {
14	this.sid = sid;
15	}
16	public String getSname() {
17	return sname;
18	}
19	public void setSname(String sname) {
20	this.sname = sname;
21	}
22	public String getSaddr() {
23	return saddr;
24	}
25	public void setSaddr(String saddr) {
26	this.saddr = saddr;
27	}
28	public Branch getBranch() {
29	return branch;
30	}
31	public void setBranch(Branch branch) {
32	this.branch = branch;
33	}
34
35
36	}
37

EX: Multiple Students have joined with single branch — Branch.hbm.xml

Example59

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Branch" table="branch">
8	<id name="bid" column="BID" length="5"/>
9	<property name="bname" column="BNAME" length="10"/>
10	</class>
11	</hibernate-mapping>
12

EX: Multiple Students have joined with single branch — Student.hbm.xml

Example60

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Student" table="student">
8	<id name="sid" column="SID" length="5"/>
9	<property name="sname" column="SNAME" length="10"/>
10	<property name="saddr" column="SADDR" length="10"/>
11	<many-to-one name="branch" class="com.durgasoft.pojo.Branch" cascade="all"/>
12	</class>
13	</hibernate-mapping>
14

EX: Multiple Students have joined with single branch — Test.java

Example61

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.Branch;
12	import com.durgasoft.pojo.Student;
13
14	public class Test {
15
16	public static void main(String[] args)throws Exception {
17	Configuration config = new Configuration();
18	config.configure();
19	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
20	builder = builder.applySettings(config.getProperties());
21	StandardServiceRegistry registry = builder.build();
22	SessionFactory sessionFactory = config.buildSessionFactory(registry);
23	Session session = sessionFactory.openSession();
24
25	Branch branch = new Branch();
26	branch.setBid("B-111");
27	branch.setBname("CS");
28
29	Student std1 = new Student();
30	std1.setSid("S-111");
31	std1.setSname("AAA");
32	std1.setSaddr("Hyd");
33	std1.setBranch(branch);
34
35	Student std2 = new Student();
36	std2.setSid("S-222");
37	std2.setSname("BBB");
38	std2.setSaddr("Hyd");
39	std2.setBranch(branch);
40
41	Student std3 = new Student();
42	std3.setSid("S-333");
43	std3.setSname("BBB");
44	std3.setSaddr("Hyd");
45	std3.setBranch(branch);
46
47	Transaction tx = session.beginTransaction();
48	session.save(std1);
49	session.save(std2);
50	session.save(std3);
51	tx.commit();
52	System.out.println("Students are stored Successfully");
53	session.close();
54	sessionFactory.close();
55
56
57	}
58
59	}
60

EX: Multiple Students have joined with single branch — Branch.java

To represent many-to-one association, JPA has provided a seperate annotation like @ManyToOne(calcade=CascadeType.ALL)

Example:

Example62

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.Column;
5	import javax.persistence.Entity;
6	import javax.persistence.Id;
7	import javax.persistence.Table;
8
9	@Entity
10	@Table(name="branch")
11	public class Branch {
12	@Id
13	@Column(name="BID", length=5)
14	private String bid;
15	@Column(name="BNAME", length=10)
16	private String bname;
17
18	public String getBid() {
19	return bid;
20	}
21	public void setBid(String bid) {
22	this.bid = bid;
23	}
24	public String getBname() {
25	return bname;
26	}
27	public void setBname(String bname) {
28	this.bname = bname;
29	}
30
31
32	}
33

EX: Multiple Students have joined with single branch — Student.java

Example63

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import javax.persistence.CascadeType;
5	import javax.persistence.Column;
6	import javax.persistence.Entity;
7	import javax.persistence.Id;
8	import javax.persistence.ManyToOne;
9	import javax.persistence.Table;
10
11	@Entity
12	@Table(name="student")
13	public class Student {
14	@Id
15	@Column(name="SID", length=5)
16	private String sid;
17	@Column(name="SNAME", length=10)
18	private String sname;
19	@Column(name="SADDR", length=10)
20	private String saddr;
21	@ManyToOne(cascade=CascadeType.ALL)
22	private Branch branch;
23
24	public String getSid() {
25	return sid;
26	}
27	public void setSid(String sid) {
28	this.sid = sid;
29	}
30	public String getSname() {
31	return sname;
32	}
33	public void setSname(String sname) {
34	this.sname = sname;
35	}
36	public String getSaddr() {
37	return saddr;
38	}
39	public void setSaddr(String saddr) {
40	this.saddr = saddr;
41	}
42	public Branch getBranch() {
43	return branch;
44	}
45	public void setBranch(Branch branch) {
46	this.branch = branch;
47	}
48
49
50	}
51

EX: Multiple Students have joined with single branch — hibernate.cfg.xml

Example64

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.username">system</property>
11	<property name="connection.password">durga</property>
12	<!-- <property name="hibernate.hbm2ddl.auto">create</property>-->
13	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
14	<property name="show_sql">true</property>
15	<mapping class="com.durgasoft.pojo.Branch"/>
16	<mapping class="com.durgasoft.pojo.Student"/>
17	</session-factory>
18	</hibernate-configuration>
19

EX: Multiple Students have joined with single branch — Test.java

Example65

JCode Cell

1
2	package com.durgasoft.test;
3
4	import org.hibernate.Session;
5	import org.hibernate.SessionFactory;
6	import org.hibernate.Transaction;
7	import org.hibernate.boot.registry.StandardServiceRegistry;
8	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
9	import org.hibernate.cfg.Configuration;
10
11	import com.durgasoft.pojo.Branch;
12	import com.durgasoft.pojo.Student;
13
14	public class Test {
15
16	public static void main(String[] args)throws Exception {
17	Configuration config = new Configuration();
18	config.configure();
19	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
20	builder = builder.applySettings(config.getProperties());
21	StandardServiceRegistry registry = builder.build();
22	SessionFactory sessionFactory = config.buildSessionFactory(registry);
23	Session session = sessionFactory.openSession();
24
25	/*
26	Branch branch = new Branch();
27	branch.setBid("B-111");
28	branch.setBname("CS");
29
30	Student std1 = new Student();
31	std1.setSid("S-111");
32	std1.setSname("AAA");
33	std1.setSaddr("Hyd");
34	std1.setBranch(branch);
35
36	Student std2 = new Student();
37	std2.setSid("S-222");
38	std2.setSname("BBB");
39	std2.setSaddr("Hyd");
40	std2.setBranch(branch);
41
42	Student std3 = new Student();
43	std3.setSid("S-333");
44	std3.setSname("BBB");
45	std3.setSaddr("Hyd");
46	std3.setBranch(branch);
47
48	Transaction tx = session.beginTransaction();
49	session.save(std1);
50	session.save(std2);
51	session.save(std3);
52	tx.commit();
53	System.out.println("Students are stored Successfully");
54	*/
55	Student std1 = (Student)session.get(Student.class, "S-111");
56	Branch branch = std1.getBranch();
57	System.out.println("Student Details");
58	System.out.println("---------------------");
59	System.out.println("Student Id :"+std1.getSid());
60	System.out.println("Student Name :"+std1.getSname());
61	System.out.println("Student Address :"+std1.getSaddr());
62	System.out.println("Branch Id :"+branch.getBid());
63	System.out.println("Branch Name :"+branch.getBname());
64	System.out.println();
65
66	Student std2 = (Student)session.get(Student.class, "S-222");
67	branch = std2.getBranch();
68	System.out.println("Student Details");
69	System.out.println("---------------------");
70	System.out.println("Student Id :"+std2.getSid());
71	System.out.println("Student Name :"+std2.getSname());
72	System.out.println("Student Address :"+std2.getSaddr());
73	System.out.println("Branch Id :"+branch.getBid());
74	System.out.println("Branch Name :"+branch.getBname());
75	System.out.println();
76
77	Student std3 = (Student)session.get(Student.class, "S-333");
78	branch = std3.getBranch();
79	System.out.println("Student Details");
80	System.out.println("---------------------");
81	System.out.println("Student Id :"+std3.getSid());
82	System.out.println("Student Name :"+std3.getSname());
83	System.out.println("Student Address :"+std3.getSaddr());
84	System.out.println("Branch Id :"+branch.getBid());
85	System.out.println("Branch Name :"+branch.getBname());
86
87	session.close();
88	sessionFactory.close();
89
90
91	}
92
93	}
94

Many-To-Many Associations — Course.java

It is a relation between entities , where multiple instances of an entity must be mapped with multiple instances of another entity. EX: Multiple Students have joined with Multiple Courses.

To repesent Many-To-Many mapping we have to use the following tags in mapping file. <set name="--" table="--" cascade="--"> <key column="---"/> <many-tomany column="--" class=""/>

</set>

 Where "<set>" tag is representing many side, where "name" attribute in <set> tag will take property name which is providing many side , where "table" attribute will take join_table name, where "cascade" will take "all", "insert", "update",.....

 Where "<key>" tag is able to take primary key of the container represented table, where "column" attribute will take that value.

 Where "<many-to-many>" tag will represent many-to-many association, where "column" attribute will take target table primary kery column name, where "class" attribute will take target class name.

Example:

Example66

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	public class Course {
5	private String cid;
6	private String cname;
7	private int ccost;
8
9	public String getCid() {
10	return cid;
11	}
12	public void setCid(String cid) {
13	this.cid = cid;
14	}
15	public String getCname() {
16	return cname;
17	}
18	public void setCname(String cname) {
19	this.cname = cname;
20	}
21	public int getCcost() {
22	return ccost;
23	}
24	public void setCcost(int ccost) {
25	this.ccost = ccost;
26	}
27
28
29
30	}
31

Many-To-Many Associations — Student.java

Example67

JCode Cell

1
2	package com.durgasoft.pojo;
3
4	import java.util.Set;
5
6	public class Student {
7	private String sid;
8	private String sname;
9	private String saddr;
10	private Set<Course> courses;
11
12	public String getSid() {
13	return sid;
14	}
15	public void setSid(String sid) {
16	this.sid = sid;
17	}
18	public String getSname() {
19	return sname;
20	}
21	public void setSname(String sname) {
22	this.sname = sname;
23	}
24	public String getSaddr() {
25	return saddr;
26	}
27	public void setSaddr(String saddr) {
28	this.saddr = saddr;
29	}
30	public Set<Course> getCourses() {
31	return courses;
32	}
33	public void setCourses(Set<Course> courses) {
34	this.courses = courses;
35	}
36	}
37

Many-To-Many Associations — Course.hbm.xml

Example68

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Course" table="course">
8	<id name="cid" column="CID" length="5"/>
9	<property name="cname" column="CNAME" length="10"/>
10	<property name="ccost" column="Ccost" length="5"/>
11
12	</class>
13	</hibernate-mapping>
14

Many-To-Many Associations — Student.hbm.xml

Example69

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-mapping PUBLIC
4	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
6	<hibernate-mapping>
7	<class name="com.durgasoft.pojo.Student" table="student">
8	<id name="sid" column="SID" length="5"/>
9	<property name="sname" column="SNAME" length="10"/>
10	<property name="saddr" column="SADDR" length="10"/>
11
12	<set name="courses" table="student_course" cascade="all">
13	<key column="sid"/>
14	<many-to-many column="cid" class="com.durgasoft.pojo.Course" />
15	</set>
16	</class>
17	</hibernate-mapping>
18

Many-To-Many Associations — hibernate.hbm.xml

Example70

JCode Cell

1
2	<?xml version="1.0" encoding="UTF-8"?>
3	<!DOCTYPE hibernate-configuration PUBLIC
4	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
5	"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
6	<hibernate-configuration>
7	<session-factory>
8	<property name="connection.driver_Class">oracle.jdbc.OracleDriver</property>
9	<property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>
10	<property name="connection.username">system</property>
11	<property name="connection.password">durga</property>
12	<property name="hibernate.hbm2ddl.auto">create</property>
13	<property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
14	<property name="show_sql">true</property>
15	<mapping resource="Course.hbm.xml"/>
16	<mapping resource="Student.hbm.xml"/>
17	</session-factory>
18	</hibernate-configuration>
19

Many-To-Many Associations — Test.java

Example71

JCode Cell

1
2	package com.durgasoft.test;
3
4	import java.util.HashSet;
5	import java.util.Set;
6
7	import org.hibernate.Session;
8	import org.hibernate.SessionFactory;
9	import org.hibernate.Transaction;
10	import org.hibernate.boot.registry.StandardServiceRegistry;
11	import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
12	import org.hibernate.cfg.Configuration;
13
14	import com.durgasoft.pojo.Course;
15	import com.durgasoft.pojo.Student;
16
17
18	public class Test {
19
20	public static void main(String[] args)throws Exception {
21	Configuration config = new Configuration();
22	config.configure();
23	StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder();
24	builder = builder.applySettings(config.getProperties());
25	StandardServiceRegistry registry = builder.build();
26	SessionFactory sessionFactory = config.buildSessionFactory(registry);
27	Session session = sessionFactory.openSession();
28
29	Course c1 = new Course();
30	c1.setCid("C-111");
31	c1.setCname("C");
32	c1.setCcost(500);
33	Course c2 = new Course();
34	c2.setCid("C-222");
35	c2.setCname("C++");
36	c2.setCcost(1000);
37	Course c3 = new Course();
38	c3.setCid("C-333");
39	c3.setCname("Java");
40	c3.setCcost(2000);
41	Set<Course> courses = new HashSet<Course>();
42	courses.add(c1);
43	courses.add(c2);
44	courses.add(c3);
45
46	Student std1 = new Student();
47	std1.setSid("S-111");
48	std1.setSname("AAA");
49	std1.setSaddr("Hyd");
50	std1.setCourses(courses);
51	Student std2 = new Student();
52	std2.setSid("S-222");
53	std2.setSname("BBB");
54	std2.setSaddr("Hyd");
55	std2.setCourses(courses);
56	Student std3 = new Student();
57	std3.setSid("S-333");
58	std3.setSname("CCC");
59	std3.setSaddr("Hyd");
60	std3.setCourses(courses);
61
62	Transaction tx = session.beginTransaction();
63	session.save(std1);
64	session.save(std2);
65	session.save(std3);
66	tx.commit();
67	System.out.println("Students Inserted Successfully");
68
69	session.close();
70	sessionFactory.close();
71	}
72	}
73

Retrieving the data through annotation — Hibernate.cfg.xml

To represent many _to_many association mapping,EJB3 has provide the following annotations.

@ManyTomany(cascade=”_”) @jointable(name=”_”,joincolumns=”_”,inversejoincolumns=”_”) @joincolumn(name=”_”)

 Where, @Manyto many annotation will represent many_to_many association mapping.  Where,@jointable annotation will represent the meta data about the join table.

 Name->join table nam e,joincolumns->array of @joincolumn annotation;  Inversejoincolumn->array on @joincolumn annonation to represent inverse

join key configuration.

 Where, @joincolumn annotation can be used to represent a column available in join table.  Where @join column annotation must be user as nested annotation to @jointable

annotation.

Example72

JCode Cell

1
2	<hibernate-configuration>
3	----
4	<mapping class =”student”/>
5	<mapping class=”course”/>
6	<session-factory>
7	</hibernate-configuration>
8

Retrieving the data through annotation — Student.java

Example73

JCode Cell

1
2	Import java.util.*;
3	Import javx.persistence.*;
4	@entity
5	@table(name=”student”)
6	Public class student
7	{
8	@id
9	@column (name=”sid”);
10	Private string sid;
11	@column(name=”sname”)
12	Private string sname;
13	Private string sname;
14	@Many to Many(cascade=cascadetype.All)
15
16
17
18	@JoinTable(name=”student_course”,joinColumns={@JoinColumn(name=”sid”)},inverseJoinColumns={@JoinColumn(name=”cid”)})
19	Private Collection<Course> courses;
20	setXxx(-);
21	getXxx( );
22	}
23

Retrieving the data through annotation — Course.java

Example74

JCode Cell

1
2	Import javax.persistence.*;
3	@Entity
4	@Table(name=”course”)
5	Public class Course
6	{
7	@Id
8	@Column(name=”cid”)
9	Private String cid;
10	@Column(name=”cname”)
11	Private String cname;
12	setXxx(-);
13	getXxx(-);
14

Retrieving the data through annotation — ClientApp.java

Example75

JCode Cell

1
2	Import java.util.*;
3	Import org.hibernate.*;
4	Import org.hibernate.cfg.*;
5	Public class ClientApp
6	{
7	Public static void main(String
8	{
9	Configuration cfg=new AnnotationConfiguration( );
10	cfg.configure();
11	SessionFactory sf=cfg.buildSessionFactory();
12	Session s=sf.openSession( );
13	Student s1=(Student)s.get(“Student”,”s1”);
14	Sop1(“StudentDetails”);
15	Sopl(“……..”);
16	Sopl (“student id””+s1.getSid());
17	Sopl (“Student name”.”+s1.getSname());
18	Collection c=s1.getCourses();
19	Iterator it=c.iterartor( );
20	Sopl (“course details”);
21	Sopl (“……..”);
22	Sopl (“CID NAME”);
23	Sopl (“……..”);
24	While
25	{
26	Course crs=(Course)it.next( );
27	Sopl (crs.getCid()+” “+crs.getCname());
28	}
29	Sopl (“………”);
30	Student s2=(Student)s.get(“Student”,”s2”);
31	Sopl (“Student Details”);
32	Sopl (“………”);
33	Sopl(student id..”+s2.getSid());
34	C=s2.getCourses();
35	It=c.iterate();
36	Sopl(“Course Details”);
37	Sopl(“………”);
38	Sopl(“CID CNAME”);
39	While(it.hasNext())
40	{
41	Course crs =(Course)it.next( );
42	Sopl(crs.getCid()+” “+crs.getCname());
43	s.close();
44	}
45	}
46

📝 Key Takeaways

Key ideas of Hibernate - Inheritance Mapping (Table Per Subclass) explained simply
Ready-to-use code examples
Exam-style questions at the end

Hibernate

Nearby lessons

Hibernate - Inheritance Mapping (Table Per Subclass)

01Inheritance Mapping (Table Per Subclass) — Account.java

02Inheritance Mapping (Table Per Subclass) — StudentAccount.java

03Inheritance Mapping (Table Per Subclass) — EmployeeAccount.java

04Inheritance Mapping (Table Per Subclass) — Account.hbm.xml

05Inheritance Mapping (Table Per Subclass) — hibernate.cfg.xml

06Inheritance Mapping (Table Per Subclass) — Test.java

07Inheritance Mapping (Table Per Subclass) — Account.java

08Inheritance Mapping (Table Per Subclass) — StudentAccount.java

09Inheritance Mapping (Table Per Subclass) — EmployeeAccount.java

10Inheritance Mapping (Table Per Subclass) — hibernate.cfg.xml

11Inheritance Mapping (Table Per Subclass) — Test.java

12Table Per Sub class — Payment.java

13Table Per Sub class — CardPayment.java

14Table Per Sub class — ChequePayment.java

15Table Per Sub class — payment.hbm.xml

16Table Per Sub class — hibernate.cfg.xml

17Table Per Sub class — Test.java

18Table Per Sub class — Payment.java

19Table Per Sub class — CardPayment.java

20Table Per Sub class — ChequePayment.java

21Table Per Sub class — hibernate.cfg.xml

22Table Per Sub class — Test.java

23Table Per Concreate Class — Person.java

24Table Per Concreate Class — Employee.java

25Table Per Concreate Class — Customer.java

26Table Per Concreate Class — Person.hbm.xml

27Table Per Concreate Class — hibernate.cfg.xml

28Table Per Concreate Class — Test.java

29Database — Person.java

30Database — Employee.java

31Database — Customer.java

32Database — hibernate.cfg.xml

33Database — Test.java

34Association Mapping

35Association Mapping

36One-To-One Association Mapping — Employee.java

37One-To-One Association Mapping — Account.java

38One-To-One Association Mapping — Employee.hbm.xml

39One-To-One Association Mapping — Account.hbm.xml

40One-To-One Association Mapping — hibernate.cfg.xml

41One-To-One Association Mapping — Test.java

42One-To-One Association Mapping — Employee.java

43One-To-One Association Mapping — Account.java

44One-To-One Association Mapping — hibernate.cfg.xml

45One-To-One Association Mapping — Test.java

46One-To-Many Association — Employee.java

47One-To-Many Association — Department.java

48One-To-Many Association — Employee.hbm.xml

49One-To-Many Association — Department.hbm.xml

50One-To-Many Association — hibernate.cfg.xml

51One-To-Many Association — Test.java

52One-To-Many Association — Employee.java

53One-To-Many Association — Department.java

54One-To-Many Association — hibernate.cfg.xml

55One-To-Many Association — Test.java

56Many-To-One Association

57EX: Multiple Students have joined with single branch — Branch.java

58EX: Multiple Students have joined with single branch — Student.java

59EX: Multiple Students have joined with single branch — Branch.hbm.xml

60EX: Multiple Students have joined with single branch — Student.hbm.xml

61EX: Multiple Students have joined with single branch — Test.java

62EX: Multiple Students have joined with single branch — Branch.java

63EX: Multiple Students have joined with single branch — Student.java

64EX: Multiple Students have joined with single branch — hibernate.cfg.xml

65EX: Multiple Students have joined with single branch — Test.java

66Many-To-Many Associations — Course.java

67Many-To-Many Associations — Student.java

68Many-To-Many Associations — Course.hbm.xml

69Many-To-Many Associations — Student.hbm.xml

70Many-To-Many Associations — hibernate.hbm.xml

71Many-To-Many Associations — Test.java

72Retrieving the data through annotation — Hibernate.cfg.xml

73Retrieving the data through annotation — Student.java

74Retrieving the data through annotation — Course.java

75Retrieving the data through annotation — ClientApp.java

Inheritance Mapping (Table Per Subclass) — Account.java

Inheritance Mapping (Table Per Subclass) — StudentAccount.java

Inheritance Mapping (Table Per Subclass) — EmployeeAccount.java

Inheritance Mapping (Table Per Subclass) — Account.hbm.xml

Inheritance Mapping (Table Per Subclass) — hibernate.cfg.xml

Inheritance Mapping (Table Per Subclass) — Test.java

Inheritance Mapping (Table Per Subclass) — Account.java

Inheritance Mapping (Table Per Subclass) — StudentAccount.java

Inheritance Mapping (Table Per Subclass) — EmployeeAccount.java

Inheritance Mapping (Table Per Subclass) — hibernate.cfg.xml

Inheritance Mapping (Table Per Subclass) — Test.java

Table Per Sub class — Payment.java

Table Per Sub class — CardPayment.java

Table Per Sub class — ChequePayment.java

Table Per Sub class — payment.hbm.xml

Table Per Sub class — hibernate.cfg.xml

Table Per Sub class — Test.java

Table Per Sub class — Payment.java

Table Per Sub class — CardPayment.java

Table Per Sub class — ChequePayment.java

Table Per Sub class — hibernate.cfg.xml

Table Per Sub class — Test.java

Table Per Concreate Class — Person.java

Table Per Concreate Class — Employee.java

Table Per Concreate Class — Customer.java

Table Per Concreate Class — Person.hbm.xml

Table Per Concreate Class — hibernate.cfg.xml

Table Per Concreate Class — Test.java

Database — Person.java

Database — Employee.java

Database — Customer.java

Database — hibernate.cfg.xml

Database — Test.java

Association Mapping

Association Mapping

One-To-One Association Mapping — Employee.java

One-To-One Association Mapping — Account.java

One-To-One Association Mapping — Employee.hbm.xml

One-To-One Association Mapping — Account.hbm.xml

One-To-One Association Mapping — hibernate.cfg.xml

One-To-One Association Mapping — Test.java

One-To-One Association Mapping — Employee.java

One-To-One Association Mapping — Account.java

One-To-One Association Mapping — hibernate.cfg.xml

One-To-One Association Mapping — Test.java

One-To-Many Association — Employee.java

One-To-Many Association — Department.java

One-To-Many Association — Employee.hbm.xml

One-To-Many Association — Department.hbm.xml

One-To-Many Association — hibernate.cfg.xml

One-To-Many Association — Test.java

One-To-Many Association — Employee.java

One-To-Many Association — Department.java

One-To-Many Association — hibernate.cfg.xml

One-To-Many Association — Test.java

Many-To-One Association

EX: Multiple Students have joined with single branch — Branch.java

EX: Multiple Students have joined with single branch — Student.java

EX: Multiple Students have joined with single branch — Branch.hbm.xml

EX: Multiple Students have joined with single branch — Student.hbm.xml

EX: Multiple Students have joined with single branch — Test.java

EX: Multiple Students have joined with single branch — Branch.java

EX: Multiple Students have joined with single branch — Student.java

EX: Multiple Students have joined with single branch — hibernate.cfg.xml

EX: Multiple Students have joined with single branch — Test.java

Many-To-Many Associations — Course.java

Many-To-Many Associations — Student.java

Many-To-Many Associations — Course.hbm.xml

Many-To-Many Associations — Student.hbm.xml

Many-To-Many Associations — hibernate.hbm.xml

Many-To-Many Associations — Test.java

Retrieving the data through annotation — Hibernate.cfg.xml

Retrieving the data through annotation — Student.java

Retrieving the data through annotation — Course.java

Retrieving the data through annotation — ClientApp.java