Hibernate Update
In this section we will discuss various method of update.
Hibernate Update:
Hibernate provides minimal object oriented HQL as well as highly object oriented criteria concept. Hibernate also provide native SQL query.
The work of UPDATE clause is to update existing record of the table by updating one or more properties of your persistent object. Here we going to discuss various methods of update.
session.update()-this method update the existing record.
Example : In this example we are updating the student name whose roll number is 3 .
package net.roseindia.main;
import net.roseindia.table.Student;
import net.roseindia.util.HibernateUtil;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
public class HibernateUpdate {
public static void main(String args[]) {
Session session = HibernateUtil.getSessionFactory().openSession();
Transaction transaction = session.beginTransaction();
int roll = 3;
Student student = (Student) session.load(Student.class, roll);
try {
student.setName("Johny");
session.update(student);
transaction.commit();
System.out.println("Update Successfully");
session.close();
} catch (HibernateException e) {
e.printStackTrace();
}
}
}
session.saveorupdate()- It saves the record if primary key does not exist otherwise it update the record.
session.saveOrUpdate(student);
session.merge() - It is bit complex. It works with the
persistent object. It checks for the persistent instance existence.
If present copy the state of the given object onto the persistent instance. If
not it load it from database or create new one.
The persistent instance returned which remain detached. It does not associated
with session.
session.merge(student);
query.executeUpdate() - It execute your update query or delete the statement and also return the number of entities updated or deleted.
Example:
package net.roseindia.main;
import net.roseindia.util.HibernateUtil;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
public class MainClazz {
public static void main(String[] args) {
Session session = HibernateUtil.getSessionFactory().openSession();
String newName = "Ron";
String oldName = "Rohnald";
try {
Transaction transaction = session.beginTransaction();
String hql = "UPDATE Student stud SET stud.name='" + newName
+ "' WHERE stud.name='" + oldName + "'";
Query query = session.createQuery(hql);
int rowCount = query.executeUpdate();
transaction.commit();
System.out.println("Rows affected: " + rowCount);
session.flush();
} catch (HibernateException e) {
e.printStackTrace();
} finally {
session.close();
}
}
}