4 to 6 : 27 - JUNE - 2018 : hibernate

* hibernate.properties file *

# dialect : for this DB hibernate will generate sql
hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

# db's driver class
hibernate.connection.driver_class=com.mysql.jdbc.Driver

# db's url
hibernate.connection.url=jdbc:mysql://localhost:3306/june26

# db's username and password
hibernate.connection.username=root
hibernate.connection.password=root

# hey hibernate please create tables for me automatically
hibernate.hbm2ddl.auto=update

# hibernate please show the sql that you produce
hibernate.show_sql=true

# hibernate please show the sql in a good format
hibernate.format_sql=true

============================

package beans;

public class Person 
{
// private data members
private int id;
private String name, city;
private int age;

// setters and getters
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCity() {
return city;
}
public void setCity(String city) {
System.out.println("lage loo");
this.city = city;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}

public Person() {
System.out.println("object of person created");
}
}
============================
* Person.hbm.xml file *

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

<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

   <hibernate-mapping package="beans">
   
    <class name="Person" table="person_info">
    <id name="id" column="person_id">
    <generator class="assigned">
    </generator>
    </id>
    <property name="name" column="person_name"></property>
    <property name="age" column="person_age"></property>
    <property name="city" column="person_city"></property>
    </class>
   

   </hibernate-mapping>
============================
package beans;

import java.util.Scanner;

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

public class FetchSingleObject 
{
public static void main(String[] args) 
{
Session session = new Configuration().
addResource("Person.hbm.xml").buildSessionFactory()
.openSession();

Scanner sc = new Scanner(System.in);

System.out.print("Input person id: ");
int pId = sc.nextInt();

// fetch an object of person 
Person p = session.get(Person.class, pId);

// check for null object
if(p != null)
{
// fetch data from p using getters
System.out.println(p.getName()+":"+p.getAge()
+":"+p.getCity());
}
else
{
System.out.println("invalid id");
}

// close session
session.close();
}

}

============================

package beans;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.query.Query;

public class FetchListOfObjects 
{
public static void main(String[] args) 
{
Session session = new Configuration().
addResource("Person.hbm.xml").buildSessionFactory()
.openSession();

// get object of query
Query query = session.createQuery("from Person where id >= 2");

// get a list of all the persons from the table
List<Person> listOfPersons = query.list();

// get object from list using for each loop
for(Person p : listOfPersons)
{
// fetch data from p using getters
System.out.println(p.getName()+":"+p.getAge()
+":"+p.getCity());
}

// close session
session.close();
}

}

============================