One to many
1. http://www.mkyong.com/hibernate/different-between-cascade-and-inverse/
2. http://viralpatel.net/blogs/hibernate-one-to-many-xml-mapping-tutorial/
3. http://www.mkyong.com/hibernate/inverse-true-example-and-explanation/
4.http://www.mkyong.com/hibernate/hibernate-cascade-example-save-update-delete-and-delete-orphan/
5. http://technicalmumbojumbo.wordpress.com/2007/08/18/investigating-hibernate-associations-one-to-many/
CREATE TABLE hibdept
(
id number primary key,
name varchar2(20)
);
create table hibemp
(
id number primary key,
name varchar2(30) ,
deptid number ,
constraint consthibemp FOREIGN KEY (deptid) REFERENCES hibdept(id)
)
create sequence hibdept_seq
create sequence hibemp_seq
1. Department.java
package dptemp;
import java.util.Set;
public class Department {
int id;
String name;
Set employees;
public Department() {
super();
}
public Department(String name) {
super();
this.name = name;
}
getter/setter
2. Employee.java
package dptemp;
public class Employee {
int empid;
String empname;
Department department;
public Employee() {
super();
}
public Employee(String empname) {
super();
this.empname = empname;
}
getter / setter
}
3. department.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping auto-import="false" package="dptemp">
<class name="dptemp.Department" table="hibdept">
<meta attribute="class-description">
This class contains the department detail.
</meta>
<id name="id" type="int" column="id">
<generator class="sequence">
<param name="sequence">hibdept_seq</param>
</generator>
</id>
<set name="employees" cascade="all" inverse="true" lazy="true" fetch="select">
<key column="deptid"/>
<one-to-many class="dptemp.Employee"/>
</set>
<property name="name" column="name" type="string"/>
</class>
<class name="dptemp.Employee" table="hibemp">
<meta attribute="class-description">
This class contains the certificate records.
</meta>
<id name="empid" type="int" column="id">
<generator class="sequence">
<param name="sequence">hibemp_seq</param>
</generator>
</id>
<property name="empname" column="name" type="string"/>
<many-to-one name="department" class="dptemp.Department" fetch="select">
<column name="deptid" not-null="true" />
</many-to-one>
</class>
</hibernate-mapping>
4. main
package dptemp;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import dptemp.Employee;
import dptemp.Department;
public class Main {
private static SessionFactory factory;
public static void main(String[] args) {
try{
factory = new Configuration().configure().buildSessionFactory();
}catch (Throwable ex) {
System.err.println("Failed to create sessionFactory object." + ex);
throw new ExceptionInInitializerError(ex);
}
Main ME = new Main();
HashSet<Employee> employees1 = new HashSet<Employee>();
Employee e1 = new Employee("A1");
Employee e2 = new Employee("B1");
Employee e3 = new Employee("C1");
employees1.add(e1);
employees1.add(e2);
employees1.add(e3);
int deptid1 = ME.addDepartmentEmployee("Department1", employees1);
System.out.println("dept1 = "+ deptid1);
HashSet<Employee> employees2 = new HashSet<Employee>();
Employee e21 = new Employee("A2");
Employee e22 = new Employee("B2");
Employee e23 = new Employee("C2");
employees2.add(e21);
employees2.add(e22);
employees2.add(e23);
int deptid2 = ME.addDepartmentEmployee("Department2", employees2);
System.out.println("dept2 = "+ deptid2);
ME.displayAll();
Employee e22 = new Employee("D1");
ME.addEmployee(45, e22);
System.out.println("Record added");
ME.displayAll();
System.out.println("showing department no " + 48);
ME.displayDepartmentName(48);
System.out.println("showing department no " + 81);
ME.displayDepartmentNameFromEmployeeid(81);
}
public int addDepartmentEmployee(String deptname , HashSet<Employee> employees){
Department department = new Department(deptname);
for(Iterator<Employee> it = employees.iterator();it.hasNext();)
{
Employee e = it.next();
e.setDepartment(department);
}
department.setEmployees(employees);
int departmentid =0;
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
departmentid = (Integer) session.save(department);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
return departmentid;
}
public void displayAll()
{
try{
Session session = factory.openSession();
List<Department> departments =(List<Department>) session.createQuery("FROM dptemp.Department").list();
Iterator<Department> it =(Iterator<Department>) departments.iterator();
while(it.hasNext()){
Department dept = it.next();
System.out.println("\n\nDepartment id =" + dept.getId() + " Name = " + dept.getName());
Iterator iti = dept.getEmployees().iterator();
while(iti.hasNext()){
Employee emp = (Employee)iti.next();
System.out.println(" emp id =" + emp.getEmpid() + " Name = " + emp.getEmpname());
}
}
session.close();
}
catch(Exception e){
e.printStackTrace();
}
}
public void displayDepartmentName(int deptid)
{
try{
Session session = factory.openSession();
Query q = session.createQuery("FROM dptemp.Department d where d.id = ?");
q.setInteger(0, deptid);
List<Department> departments = q.list(); //(List<Department>) session.createQuery("FROM dptemp.Department").list();
Iterator<Department> it =(Iterator<Department>) departments.iterator();
while(it.hasNext()){
Department dept = it.next();
System.out.println("\n\nDepartment id =" + dept.getId() + " Name = " + dept.getName());
Iterator iti = dept.getEmployees().iterator();
while(iti.hasNext()){
Employee emp = (Employee)iti.next();
System.out.println(" emp id =" + emp.getEmpid() + " Name = " + emp.getEmpname());
}
}
session.close();
}
catch(Exception e){
e.printStackTrace();
}
}
public void displayDepartmentNameFromEmployeeid(int empid)
{
try{
Session session = factory.openSession();
Query q = session.createQuery("FROM dptemp.Employee e where e.empid = ?");
q.setInteger(0, empid);
List<Employee> employees = q.list(); //(List<Department>) session.createQuery("FROM dptemp.Department").list();
Iterator<Employee> it =(Iterator<Employee>) employees.iterator();
while(it.hasNext()){
Employee emp = it.next();
System.out.println("\n\n Employee id =" + emp.getEmpid()+ " Name = " + emp.getEmpname());
Department d = emp.getDepartment();
System.out.println("\n\n its Department id =" + d.getId() + " Name = " + d.getName());
}
session.close();
}
catch(Exception e){
e.printStackTrace();
}
}
public void addEmployee(int deptid , Employee employee){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
Department d = (Department) session.load(Department.class, deptid);
d.getEmployees().add(employee);
session.saveOrUpdate(d);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
}
1. http://www.mkyong.com/hibernate/different-between-cascade-and-inverse/
2. http://viralpatel.net/blogs/hibernate-one-to-many-xml-mapping-tutorial/
3. http://www.mkyong.com/hibernate/inverse-true-example-and-explanation/
4.http://www.mkyong.com/hibernate/hibernate-cascade-example-save-update-delete-and-delete-orphan/
5. http://technicalmumbojumbo.wordpress.com/2007/08/18/investigating-hibernate-associations-one-to-many/
CREATE TABLE hibdept
(
id number primary key,
name varchar2(20)
);
create table hibemp
(
id number primary key,
name varchar2(30) ,
deptid number ,
constraint consthibemp FOREIGN KEY (deptid) REFERENCES hibdept(id)
)
create sequence hibdept_seq
create sequence hibemp_seq
1. Department.java
package dptemp;
import java.util.Set;
public class Department {
int id;
String name;
Set employees;
public Department() {
super();
}
public Department(String name) {
super();
this.name = name;
}
getter/setter
}
2. Employee.java
package dptemp;
public class Employee {
int empid;
String empname;
Department department;
public Employee() {
super();
}
public Employee(String empname) {
super();
this.empname = empname;
}
getter / setter
}
3. department.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping auto-import="false" package="dptemp">
<class name="dptemp.Department" table="hibdept">
<meta attribute="class-description">
This class contains the department detail.
</meta>
<id name="id" type="int" column="id">
<generator class="sequence">
<param name="sequence">hibdept_seq</param>
</generator>
</id>
<set name="employees" cascade="all" inverse="true" lazy="true" fetch="select">
<key column="deptid"/>
<one-to-many class="dptemp.Employee"/>
</set>
<property name="name" column="name" type="string"/>
</class>
<class name="dptemp.Employee" table="hibemp">
<meta attribute="class-description">
This class contains the certificate records.
</meta>
<id name="empid" type="int" column="id">
<generator class="sequence">
<param name="sequence">hibemp_seq</param>
</generator>
</id>
<property name="empname" column="name" type="string"/>
<many-to-one name="department" class="dptemp.Department" fetch="select">
<column name="deptid" not-null="true" />
</many-to-one>
</class>
</hibernate-mapping>
4. main
package dptemp;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import dptemp.Employee;
import dptemp.Department;
public class Main {
private static SessionFactory factory;
public static void main(String[] args) {
try{
factory = new Configuration().configure().buildSessionFactory();
}catch (Throwable ex) {
System.err.println("Failed to create sessionFactory object." + ex);
throw new ExceptionInInitializerError(ex);
}
Main ME = new Main();
HashSet<Employee> employees1 = new HashSet<Employee>();
Employee e1 = new Employee("A1");
Employee e2 = new Employee("B1");
Employee e3 = new Employee("C1");
employees1.add(e1);
employees1.add(e2);
employees1.add(e3);
int deptid1 = ME.addDepartmentEmployee("Department1", employees1);
System.out.println("dept1 = "+ deptid1);
HashSet<Employee> employees2 = new HashSet<Employee>();
Employee e21 = new Employee("A2");
Employee e22 = new Employee("B2");
Employee e23 = new Employee("C2");
employees2.add(e21);
employees2.add(e22);
employees2.add(e23);
int deptid2 = ME.addDepartmentEmployee("Department2", employees2);
System.out.println("dept2 = "+ deptid2);
ME.displayAll();
Employee e22 = new Employee("D1");
ME.addEmployee(45, e22);
System.out.println("Record added");
ME.displayAll();
System.out.println("showing department no " + 48);
ME.displayDepartmentName(48);
System.out.println("showing department no " + 81);
ME.displayDepartmentNameFromEmployeeid(81);
}
public int addDepartmentEmployee(String deptname , HashSet<Employee> employees){
Department department = new Department(deptname);
for(Iterator<Employee> it = employees.iterator();it.hasNext();)
{
Employee e = it.next();
e.setDepartment(department);
}
department.setEmployees(employees);
int departmentid =0;
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
departmentid = (Integer) session.save(department);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
return departmentid;
}
public void displayAll()
{
try{
Session session = factory.openSession();
List<Department> departments =(List<Department>) session.createQuery("FROM dptemp.Department").list();
Iterator<Department> it =(Iterator<Department>) departments.iterator();
while(it.hasNext()){
Department dept = it.next();
System.out.println("\n\nDepartment id =" + dept.getId() + " Name = " + dept.getName());
Iterator iti = dept.getEmployees().iterator();
while(iti.hasNext()){
Employee emp = (Employee)iti.next();
System.out.println(" emp id =" + emp.getEmpid() + " Name = " + emp.getEmpname());
}
}
session.close();
}
catch(Exception e){
e.printStackTrace();
}
}
public void displayDepartmentName(int deptid)
{
try{
Session session = factory.openSession();
Query q = session.createQuery("FROM dptemp.Department d where d.id = ?");
q.setInteger(0, deptid);
List<Department> departments = q.list(); //(List<Department>) session.createQuery("FROM dptemp.Department").list();
Iterator<Department> it =(Iterator<Department>) departments.iterator();
while(it.hasNext()){
Department dept = it.next();
System.out.println("\n\nDepartment id =" + dept.getId() + " Name = " + dept.getName());
Iterator iti = dept.getEmployees().iterator();
while(iti.hasNext()){
Employee emp = (Employee)iti.next();
System.out.println(" emp id =" + emp.getEmpid() + " Name = " + emp.getEmpname());
}
}
session.close();
}
catch(Exception e){
e.printStackTrace();
}
}
public void displayDepartmentNameFromEmployeeid(int empid)
{
try{
Session session = factory.openSession();
Query q = session.createQuery("FROM dptemp.Employee e where e.empid = ?");
q.setInteger(0, empid);
List<Employee> employees = q.list(); //(List<Department>) session.createQuery("FROM dptemp.Department").list();
Iterator<Employee> it =(Iterator<Employee>) employees.iterator();
while(it.hasNext()){
Employee emp = it.next();
System.out.println("\n\n Employee id =" + emp.getEmpid()+ " Name = " + emp.getEmpname());
Department d = emp.getDepartment();
System.out.println("\n\n its Department id =" + d.getId() + " Name = " + d.getName());
}
session.close();
}
catch(Exception e){
e.printStackTrace();
}
}
public void addEmployee(int deptid , Employee employee){
Session session = factory.openSession();
Transaction tx = null;
try{
tx = session.beginTransaction();
Department d = (Department) session.load(Department.class, deptid);
d.getEmployees().add(employee);
session.saveOrUpdate(d);
tx.commit();
}catch (HibernateException e) {
if (tx!=null) tx.rollback();
e.printStackTrace();
}finally {
session.close();
}
}
}
