How to Insert a Records using Many to One Relationship example using Hibernate Framework

Many-to-One :

Many-to-One relationship means many no.of employees having one address(same).Here multiple  Employee objects having one address object.

//creating two tables for many-to-one relatioship

create table EMPLOYEE ( id INT(11) NOT NULL auto_increment,  first_name VARCHAR(20),   last_name  VARCHAR(20),   salary     INT(11),   address    INT NOT NULL,   PRIMARY KEY (id));

create table ADDRESS ( id INT NOT NULL auto_increment, street_name VARCHAR(40),  city_name VARCHAR(40), state_name VARCHAR(40) default NULL,  zipcode VARCHAR(10),PRIMARY KEY (id));

Step1: developing pojo classes for Address and Employee Tables

Address.java

package util;

public class Address implements java.io.Serializable {

       // Fields

       private Integer id;

       private String streetName;

       private String cityName;

       private String stateName;

       private String zipcode;

       // Constructors

       /** default constructor */

       public Address() {

       }

       /** full constructor */

       public Address(String streetName, String cityName, String stateName,

                     String zipcode) {

              this.streetName = streetName;

              this.cityName = cityName;

              this.stateName = stateName;

              this.zipcode = zipcode;

       }

       // Property accessors

       // write here setters and getters methods for above property

}

Employee.java

package util;

public class Employee implements java.io.Serializable {

       // Fields

       private Integer id;

       private String firstName;

       private String lastName;

       private Integer salary;

       private Address address;

       // Constructors

       /** default constructor */

       public Employee() {

       }

       /** full constructor */

       public Employee(String firstName, String lastName, Integer salary,

                     Address address) {

              this.firstName = firstName;

              this.lastName = lastName;

              this.salary = salary;

              this.address = address;

       }

       //  provide setters and getters methods  all the property’s

}

Step 2:Develop a hbm files for Pojo classes Employee and Address tables

Address.hbm.xml

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

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<!--

    Mapping file autogenerated by MyEclipse Persistence Tools

-->

<hibernate-mapping>

    <class name="util.Address" table="address" catalog="icepages">

        <id name="id" type="java.lang.Integer">

            <column name="id" />

            <generator class="identity" />

        </id>

        <property name="streetName" type="java.lang.String">

            <column name="street_name" length="40" />

        </property>

        <property name="cityName" type="java.lang.String">

            <column name="city_name" length="40" />

        </property>

        <property name="stateName" type="java.lang.String">

            <column name="state_name" length="40" />

        </property>

        <property name="zipcode" type="java.lang.String">

            <column name="zipcode" length="10" />

        </property>

    </class>

</hibernate-mapping>

Employee.hbm.xml

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

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<!--

write the m<many-to-one > tag for employee...

    Mapping file autogenerated by MyEclipse Persistence Tools

-->

<hibernate-mapping>

    <class name="util.Employee" table="employee" catalog="icepages">

        <id name="id" type="java.lang.Integer">

            <column name="id" />

            <generator class="identity" />

        </id>

        <property name="firstName" type="java.lang.String">

            <column name="first_name" length="20" />

        </property>

        <property name="lastName" type="java.lang.String">

            <column name="last_name" length="20" />

        </property>

        <property name="salary" type="java.lang.Integer">

            <column name="salary" />

        </property>

        <many-to-one name="address" class="util.Address" column="address" not-null="true"></many-to-one>

    </class>

</hibernate-mapping>

             

Step3:

Develop a Dao class for how many employees having same address ….

package test;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.Transaction;

import util.Address;

import util.Employee;

import util.HibernateSessionFactory;

public class DAOAddress {

      

       public Address addAddress(String cityName,String stateName,String streetName,String zipCode )

       {

       Address address=null;

      

       SessionFactory sf=HibernateSessionFactory.getSessionFactory();

       Session s=sf.openSession();

      

       Transaction tx=s.beginTransaction();

      

       address=new Address();

       address.setCityName(cityName);

       address.setStreetName(streetName);

       address.setStateName(stateName);

       address.setZipcode(zipCode);

       Integer addressID=(Integer)s.save(address);

      

       tx.commit();

       return address;

      

       }

      

      

       public Integer addEmployee(String firstName,String lastName,Integer salary,Address address){

      

       Integer employeeId=null;

      

       SessionFactory sf=HibernateSessionFactory.getSessionFactory();

       Session s=sf.openSession();

      

       Transaction tx=s.beginTransaction();

      

       Employee employee=null;

       employee=new Employee();

       employee.setFirstName(firstName);

       employee.setLastName(lastName);

       employee.setSalary(salary);

       employee.setAddress(address);

      

       employeeId=(Integer)s.save(employee);

       tx.commit();

      

       return employeeId;

       }

}

Step4: develop a main class Test.java

package test;

import util.Address;

import util.Employee;

public class Test {

       /**

        * @param args

        */

       public static void main(String[] args) {

              // TODO Auto-generated method stub

             

              DAOAddress dao=new DAOAddress();

             

Address address=dao.addAddress

("hyd","hyd","ammerpet","500033");

Integer employee=dao.addEmployee("ashok","venna",34643,address);

       Integer employee1=dao.addEmployee("prudhvi","bnala",5525,address);

       }

}

Output:

All the Records are inserted….