adding more than one entry

[Samanthi perera]

this is my config file

<?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.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/vanila</property>
    <property name="hibernate.connection.username">root</property>
    <property name="show_sql">true</property>
    <mapping class="Employee"/>
  </session-factory>
</hibernate-configuration>

this is my employee class

import java.io.Serializable;

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

@Entity
@Table(name = "employee")
public class Employee implements Serializable {
  public Employee() {

  }
  @Id
 // @GeneratedValue
  @Column(name = "id")
  Integer id;

  @Column(name = "name")
  String name;

  public Integer getId() {
    return id;
  }

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

  public String getName() {
    return name;
  }

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

}

this is my main class

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


public class Main {

  
    public static void main(String[] args) {

        SessionFactory sessions = new AnnotationConfiguration().configure().buildSessionFactory();
        Session session = sessions.openSession();

        try {
            session.beginTransaction();
            Employee pojo = new Employee();
            pojo.setId(new Integer(5));
            pojo.setName("XYZ");           
            session.save(pojo);
            session.getTransaction().commit();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            session.close();
        }
    }
}

this is the query i used to make table

Create table Employee(

ID int2 PRIMARY KEY,

NAME nvarchar(30)

);

this code is working .
But my problem is when i try to reun this main file it gives error.

run:
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.annotations.Version <clinit>
INFO: Hibernate Annotations 3.3.1.GA
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Environment <clinit>
INFO: Hibernate 3.2.5
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Environment <clinit>
INFO: hibernate.properties not found
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: Bytecode provider name : cglib
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Environment <clinit>
INFO: using JDK 1.4 java.sql.Timestamp handling
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Configuration configure
INFO: configuring from resource: /hibernate.cfg.xml
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: Configuration resource: /hibernate.cfg.xml
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.Configuration doConfigure
INFO: Configured SessionFactory: null
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.AnnotationBinder bindClass
INFO: Binding entity from annotated class: Employee
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.annotations.EntityBinder bindTable
INFO: Bind entity Employee on table employee
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.AnnotationConfiguration secondPassCompile
INFO: Hibernate Validator not found: ignoring
Jan 30, 2010 10:09:15 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Using Hibernate built-in connection pool (not for production use!)
Jan 30, 2010 10:09:15 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Hibernate connection pool size: 20
Jan 30, 2010 10:09:15 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: autocommit mode: false
Jan 30, 2010 10:09:15 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost:3306/vanila
Jan 30, 2010 10:09:15 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: connection properties: {user=root}
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: RDBMS: MySQL, version: 5.0.45-community-nt
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC driver: MySQL-AB JDBC Driver, version: mysql-connector-java-5.1.6 ( Revision: ${svn.Revision} )
Jan 30, 2010 10:09:15 AM org.hibernate.dialect.Dialect <init>
INFO: Using dialect: org.hibernate.dialect.MySQLDialect
Jan 30, 2010 10:09:15 AM org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory
INFO: Using default transaction strategy (direct JDBC transactions)
Jan 30, 2010 10:09:15 AM org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup
INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic flush during beforeCompletion(): disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic session close at end of transaction: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch size: 15
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch updates for versioned data: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Scrollable result sets: enabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC3 getGeneratedKeys(): enabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Connection release mode: auto
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Maximum outer join fetch depth: 2
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default batch fetch size: 1
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Generate SQL with comments: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Order SQL updates by primary key: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Order SQL inserts for batching: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory createQueryTranslatorFactory
INFO: Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory
Jan 30, 2010 10:09:15 AM org.hibernate.hql.ast.ASTQueryTranslatorFactory <init>
INFO: Using ASTQueryTranslatorFactory
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query language substitutions: {}
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JPA-QL strict compliance: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Second-level cache: enabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query cache: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory createCacheProvider
INFO: Cache provider: org.hibernate.cache.NoCacheProvider
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Optimize cache for minimal puts: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Structured second-level cache entries: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Echoing all SQL to stdout
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Statistics: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Deleted entity synthetic identifier rollback: disabled
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default entity-mode: pojo
Jan 30, 2010 10:09:15 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Named query checking : enabled
Jan 30, 2010 10:09:15 AM org.hibernate.impl.SessionFactoryImpl <init>
INFO: building session factory
Jan 30, 2010 10:09:16 AM org.hibernate.impl.SessionFactoryObjectFactory addInstance
INFO: Not binding factory to JNDI, no JNDI name configured
Hibernate: insert into employee (name, id) values (?, ?)
Jan 30, 2010 10:09:16 AM org.hibernate.util.JDBCExceptionReporter logExceptions
WARNING: SQL Error: 1062, SQLState: 23000
Jan 30, 2010 10:09:16 AM org.hibernate.util.JDBCExceptionReporter logExceptions
SEVERE: Duplicate entry '5' for key 1
Jan 30, 2010 10:09:16 AM org.hibernate.event.def.AbstractFlushingEventListener performExecutions
SEVERE: Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
        at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:253)
        at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:237)
        at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:141)
        at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
        at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
        at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
        at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
        at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
        at Main.main(Main.java:21)
Caused by: java.sql.BatchUpdateException: Duplicate entry '5' for key 1
        at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1666)
        at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1082)
        at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
        at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246)
        ... 8 more
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
        at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:253)
        at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:237)
        at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:141)
        at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
        at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
        at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
        at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
        at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
        at Main.main(Main.java:21)
Caused by: java.sql.BatchUpdateException: Duplicate entry '5' for key 1
        at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1666)
        at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1082)
        at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
        at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246)
        ... 8 more
BUILD SUCCESSFUL (total time: 1 second)

i need to run this file and enter data more than one time.what are the changes i have to done?

[Vijitha Kumara]

Samanthi perera wrote:

.........
        try {
            session.beginTransaction();
            Employee pojo = new Employee();
            pojo.setId(new Integer(5));
.............        

this code is working .
But my problem is when i try to reun this main file it gives error.
i need to run this file and enter data more than one time.what are the changes i have to done?

Because you are using the same id value for each run. You should change the id each time you run the application.

[Samanthi perera]

I found we have to use generator element.
can you tell me how to chang this class with generator element?

[Vijitha Kumara]

You may use something like,

@GeneratedValue(strategy= GenerationType.AUTO ....)

Check the JPA specification/documentation of the provider for more information and relevant annotations.

[Samanthi perera]

where to put this value?

[Vijitha Kumara]

You should annotate the Id field of your bean with this and some annotations for sequences etc.. I suggest you read the JPA Specification for more details.

[ishan dave]

hi Samanthi,

the problem is at
# SEVERE: Duplicate entry '5' for key 1
# Jan 30, 2010 10:09:16 AM org.hibernate.event.def.AbstractFlushingEventListener performExecutions
# SEVERE: Could not synchronize database state with session
# org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update

for resolving this you need to change the id of you entity as you said. for that you need to use
@GeneratedValue annotation for generating your id every time you persist them.

it should be like this
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "id")
Integer id;

this way your ids will be generated automatically, there some other strategies also available for Id generation like
Identity, Sequence and Table
here what I think is some are database dependent so Table strategy is the best one and most suitable to my requirement.

if you want know more about other attributes then please try some googling like Id generation in JPA or refer the docs or post reply and I will get back with more details

thank you,
ishaan

[David Newton]

Once the question is answered it's not really necessary to answer it again.

[Samanthi perera]

i change class

import java.io.Serializable;

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 = "employee")
public class Employee implements Serializable {
  public Employee() {

  }
  @Id
  @GeneratedValue(strategy = GenerationType.AUTO)
  @Column(name = "id")
  Integer id;

  @Column(name = "name")
  String name;

  public Integer getId() {
    return id;
  }

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

  public String getName() {
    return name;
  }

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

}
[code]

then i got new error
[code]
run:
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.annotations.Version <clinit>
INFO: Hibernate Annotations 3.3.1.GA
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Environment <clinit>
INFO: Hibernate 3.2.5
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Environment <clinit>
INFO: hibernate.properties not found
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Environment buildBytecodeProvider
INFO: Bytecode provider name : cglib
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Environment <clinit>
INFO: using JDK 1.4 java.sql.Timestamp handling
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Configuration configure
INFO: configuring from resource: /hibernate.cfg.xml
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: Configuration resource: /hibernate.cfg.xml
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.Configuration doConfigure
INFO: Configured SessionFactory: null
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.AnnotationBinder bindClass
INFO: Binding entity from annotated class: Employee
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.annotations.EntityBinder bindTable
INFO: Bind entity Employee on table employee
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.AnnotationConfiguration secondPassCompile
INFO: Hibernate Validator not found: ignoring
Jan 31, 2010 9:24:30 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Using Hibernate built-in connection pool (not for production use!)
Jan 31, 2010 9:24:30 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: Hibernate connection pool size: 20
Jan 31, 2010 9:24:30 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: autocommit mode: false
Jan 31, 2010 9:24:30 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost:3306/vanila
Jan 31, 2010 9:24:30 AM org.hibernate.connection.DriverManagerConnectionProvider configure
INFO: connection properties: {user=root}
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: RDBMS: MySQL, version: 5.0.45-community-nt
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC driver: MySQL-AB JDBC Driver, version: mysql-connector-java-5.1.6 ( Revision: ${svn.Revision} )
Jan 31, 2010 9:24:30 AM org.hibernate.dialect.Dialect <init>
INFO: Using dialect: org.hibernate.dialect.MySQLDialect
Jan 31, 2010 9:24:30 AM org.hibernate.transaction.TransactionFactoryFactory buildTransactionFactory
INFO: Using default transaction strategy (direct JDBC transactions)
Jan 31, 2010 9:24:30 AM org.hibernate.transaction.TransactionManagerLookupFactory getTransactionManagerLookup
INFO: No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic flush during beforeCompletion(): disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Automatic session close at end of transaction: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch size: 15
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC batch updates for versioned data: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Scrollable result sets: enabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JDBC3 getGeneratedKeys(): enabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Connection release mode: auto
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Maximum outer join fetch depth: 2
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default batch fetch size: 1
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Generate SQL with comments: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Order SQL updates by primary key: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Order SQL inserts for batching: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory createQueryTranslatorFactory
INFO: Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory
Jan 31, 2010 9:24:30 AM org.hibernate.hql.ast.ASTQueryTranslatorFactory <init>
INFO: Using ASTQueryTranslatorFactory
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query language substitutions: {}
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: JPA-QL strict compliance: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Second-level cache: enabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Query cache: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory createCacheProvider
INFO: Cache provider: org.hibernate.cache.NoCacheProvider
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Optimize cache for minimal puts: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Structured second-level cache entries: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Echoing all SQL to stdout
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Statistics: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Deleted entity synthetic identifier rollback: disabled
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Default entity-mode: pojo
Jan 31, 2010 9:24:30 AM org.hibernate.cfg.SettingsFactory buildSettings
INFO: Named query checking : enabled
Jan 31, 2010 9:24:30 AM org.hibernate.impl.SessionFactoryImpl <init>
INFO: building session factory
Jan 31, 2010 9:24:31 AM org.hibernate.impl.SessionFactoryObjectFactory addInstance
INFO: Not binding factory to JNDI, no JNDI name configured
Hibernate: insert into employee (name) values (?)
Jan 31, 2010 9:24:31 AM org.hibernate.util.JDBCExceptionReporter logExceptions
WARNING: SQL Error: 1364, SQLState: HY000
Jan 31, 2010 9:24:31 AM org.hibernate.util.JDBCExceptionReporter logExceptions
SEVERE: Field 'ID' doesn't have a default value
org.hibernate.exception.GenericJDBCException: could not insert: [Employee]
        at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103)
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
        at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:40)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2158)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2638)
        at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:48)
        at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:250)
        at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:298)
        at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
        at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107)
        at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
        at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
        at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
        at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
        at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
        at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
        at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
        at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
        at Main.main(Main.java:20)
Caused by: java.sql.SQLException: Field 'ID' doesn't have a default value
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
        at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2019)
        at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1937)
        at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1922)
        at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:73)
        at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:33)
        ... 16 more
BUILD SUCCESSFUL (total time: 1 second)

but if i comment @GeneratedValue(strategy = GenerationType.AUTO) line it is working .