Question

I have programmed a simple hibernate app which isn’t updating the table. The following is my code. The table gets created but the it isn’t updating

** Contact.java**

 public class Contact {
private String firstName;
private String lastName;
private String email;
private long id;

public String getEmail() {
    return email;
}

public String getFirstName() {
    return firstName;
}

public String getLastName() {
    return lastName;
}

public void setEmail(String string) {
    email = string;
}

public void setFirstName(String string) {
    firstName = string;
}

public void setLastName(String string) {
    lastName = string;
}

public long getId() {
    return id;
}

public void setId(long l) {
    id = l;
}

}

FirstExample.java

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

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

    try {

        SessionFactory sessionFactory = new Configuration().configure()
                .buildSessionFactory();
        session = sessionFactory.openSession();

        System.out.println("Inserting Record");
        Contact contact = new Contact();
        contact.setId(3);
        contact.setFirstName("Tausif");
        contact.setLastName("rahmathullah");
        contact.setEmail("[e-mail]");
        session.save(contact);
        System.out.println("updated");
    } catch (Exception e) {
        System.out.println(e.getMessage());
        e.printStackTrace();
    } finally {
        if (session != null) {
            session.flush();
            session.close();
        }
    }
}
}

hibernate.cfg.xml

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

<hibernate-configuration>
 <session-factory>
  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="hibernate.connection.url">jdbc:mysql://localhost/simpHiber</property>
  <property name="hibernate.connection.username">root</property>
  <property name="hibernate.connection.password">root</property>
  <property name="hibernate.connection.pool_size">10</property>
  <property name="show_sql">true</property>
  <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
  <property name="hibernate.hbm2ddl.auto">update</property>
  <mapping resource="contact.hbm.xml"/>
 </session-factory>
</hibernate-configuration>

contact.hbm.xml

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

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

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

Answer 1

Since you are using then assigned as id you need to set different ids every time you save.

    Contact contact = new Contact();
    contact.setId(3);//Change the id every time you insert.
    contact.setFirstName("Tausif");
    contact.setLastName("rahmathullah");
    contact.setEmail("[e-mail]");
    session.save(contact);

Now, If you want update an entry instead of inserting it again use,

    session.saveOrUpdate(contact);

This will fire an update query if the id exist in data base and will insert if it is not.