-- Table: "User"

-- DROP TABLE "User";

CREATE TABLE "User"
(
  id integer NOT NULL,
  "name" text,
  lastname text,
  CONSTRAINT id PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE "User" OWNER TO postgres;

package mypack;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "User")
public class User {

   private Integer id;
   private String name;
   private String lastname;

   @Id
   @GeneratedValue(strategy = GenerationType.SEQUENCE)
   @Column(name = "id", unique = true, nullable = false)
   public Integer getid() {
      return id;
   }

   public void setid(Integer id) {
      this.id = id;
   }

   @Column(name = "name", unique = false, nullable = false)
   public String getname() {
      return name;
   }

   public void setname(String name) {
      this.name = name;
   }

   @Column(name = "lastname", unique = false, nullable = false)
   public String getlastname() {
      return lastname;
   }

   public void setlastname(String lastName) {
      this.lastname = lastName;
   }

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
      <session-factory>
         <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
         <property name="hibernate.connection.url">jdbc:postgresql://localhost/test</property>
         <property name="hibernate.connection.username">postgres</property>
         <property name="connection.password">root</property>
         <property name="connection.pool_size">1</property>
         <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
         <property name="show_sql">true</property>
         <property name="hbm2ddl.auto">create</property>
         <mapping class="mypack.User"/>         
      </session-factory>
</hibernate-configuration>

import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;

public class HibernateUtil {
   private static SessionFactory sessionFactory;

   static {
      try {
         sessionFactory = new AnnotationConfiguration().configure()
               .buildSessionFactory();
      } catch (Throwable t) {
         t.printStackTrace();
      }
   }

   public static SessionFactory getInstance() {
      return sessionFactory;
   }
}

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Hibernate: select nextval ('hibernate_sequence')
Hibernate: insert into User (lastname, name, id) values (?, ?, ?)
org.hibernate.exception.SQLGrammarException: Could not execute JDBC batch update
   at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
   at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
   at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:268)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:184)
   at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
   at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)
   at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)
   at TestConnection.saveUser(TestConnection.java:25)
   at TestConnection.main(TestConnection.java:13)
Caused by: java.sql.BatchUpdateException: Batch entry 0 insert into User (lastname, name, id) values ('rajpathak', 'hrishikesh', '10') was aborted.  Call getNextException to see the cause.
   at org.postgresql.jdbc2.AbstractJdbc2Statement$BatchResultHandler.handleError(AbstractJdbc2Statement.java:2598)
   at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1836)
   at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:407)
   at org.postgresql.jdbc2.AbstractJdbc2Statement.executeBatch(AbstractJdbc2Statement.java:2737)
   at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
   at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
   ... 9 more