CREATE TABLE student(
id int(3) NOT NULL,
firstName varchar(20) NOT NULL,
age int(2) NOT NULL,
CONSTRAINT id_pk PRIMARY KEY (id)
);

INSERT INTO student VALUES ('101','yashik','23');

SELECT * FROM student;

package com.demo.entity;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="student")
public class StudentEntity {
@Id
private int id;
private String firstName;
private int age;
//getter and setter

package com.demo.dao;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.query.Query;
import com.demo.entity.StudentEntity;
import com.demo.resources.HibernateUtility;
public class StudentDAOImpl implements StudentDAO {
@Override
public StudentEntity getStudent(Integer studentID) {
    SessionFactory sessionFactory=HibernateUtility.createSessionFactory();
    Session s1=null;
    StudentEntity stu=null;
    s1=sessionFactory.openSession();
    s1.beginTransaction();
    String st1="SELECT s FROM StudentEntity s";
    Query q1=s1.createQuery(st1);
    List<StudentEntity> l1=q1.list();
    stu.setAge(l1.get(0).getAge());
    stu.setId(l1.get(0).getId());
    stu.setFirstName(l1.get(0).getFirstName());
    if (s1 != null) {
        s1.close();
    }
    return stu;
}
}

package com.demo.resources;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class HibernateUtility {

    private static final String CONFIGURATION_LOCATION="com/demo/resources/hibernate.cfg.xml";
    private static SessionFactory sessionFactory=getSessionFactory();

    public static SessionFactory getSessionFactory() {
        if (sessionFactory == null) {
            // loads configuration and mappings
            Configuration configuration = new Configuration().configure(CONFIGURATION_LOCATION);
            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                    .applySettings(configuration.getProperties()).build();

            // builds a session factory from the service registry
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        }

        return sessionFactory;
    }
    public static SessionFactory createSessionFactory(){
        return getSessionFactory();
    }
    public static void closeSessionFactory(){
        if(!sessionFactory.isClosed()){
            sessionFactory.close();
        }
    }
    }

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/rmc</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">******</property>
        <property name="show_sql">true</property>
        <property name="connection.pool_size">1</property>

        <mapping class="com.demo.entity.StudentEntity"></mapping>
    </session-factory>
</hibernate-configuration>