StaleStateException Hibernate

[sura watthana]

Hi

I am trying to implement a many-to-many association in hibernate.
I have a simple scenario where I have two entities three tables.
one is Teacher.java with teacher table containg id and name.
the other is Student.java with student table containing id and name as well.

let me show you my java files, my tables and the hibernate mapping files.

package com.oxman.entity;
 
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;
 

public class Teacher implements Serializable{
private int id;
private String name;
private Set<Student> students;

public Teacher(){

}

public Teacher(String name){
setName(name);
}

public Teacher(String name, Student student){
this(name);
addStudent(student);
}

public Set<Student> getStudents() {
return students;
}
public void setStudents(Set<Student> students) {
this.students = students;
}
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 void addStudent(Student student) {
    if (students == null) {
    students = new HashSet();
    }
    students.add(student);
}
}

package com.oxman.entity;
 
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;
 
public class Student implements Serializable{
private int id;
private String name;
private Set<Teacher> teachers;

public Student(){

}

public Student(String name){
setName(name);
}

public Student(String name, Teacher teacher){
this(name);
addTeacher(teacher);
}

public Set<Teacher> getTeachers() {
return teachers;
}
public void setTeachers(Set<Teacher> teachers) {
this.teachers = teachers;
}
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 void addTeacher(Teacher teacher) {
    if (teachers == null) {
    teachers = new HashSet();
    }
    teachers.add(teacher);
}
}

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
<class name="com.oxman.entity.Teacher" table="teachers">
<id name="id" column="uid" type="int" unsaved-value="null">
<generator class="native"/>
</id>
<property name="name" type="string" length="255"/>
<set name="students" table="teachers_students" cascade="all">
<key column="teacher_id"/>
<many-to-many class="com.oxman.entity.Student"/>
</set>
</class>
</hibernate-mapping>


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
<class name="com.oxman.entity.Student" table="students">
<id name="id" column="uid" type="int" unsaved-value="null">
<generator class="native"/>
</id>
<property name="name" type="string" length="255"/>
<set name="teachers" table="teachers_students" cascade="all">
<key column="student_id"/>
<many-to-many class="com.oxman.entity.Teacher"/>
</set>
</class>
</hibernate-mapping>

DROP TABLE IF EXISTS `teachers`;
CREATE TABLE `teachers` (
`uid` int(11) NOT NULL auto_increment,
`name` varchar(255) default NULL,
PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `students`;
CREATE TABLE `students` (
`uid` int(11) NOT NULL auto_increment,
`name` varchar(255) default NULL,
PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `teachers_students`;
CREATE TABLE `teachers_students` (
`teacher_id` int(11) NOT NULL default '0',
`student_id` int(11) NOT NULL default '0',
PRIMARY KEY (`teacher_id`,`student_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

I have tried to run this code

package com.oxman.test;
 
import java.util.HashSet;
 
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.StaleStateException;
import org.hibernate.Transaction;
 
import com.oxman.app.HibernateFactory;
import com.oxman.entity.Student;
import com.oxman.entity.Teacher;
 
public class StudentTeacherTest {
public static void main(String[] args){

SessionFactory factory = HibernateFactory.buildSessionFactory();
Session session = HibernateFactory.openSession();
Transaction tx= session.beginTransaction();

try{    
    
Teacher teacher = new Teacher();
teacher.setName("Tom");
teacher.setStudents(new HashSet<Student>());
teacher.addStudent(new Student("Foo",teacher));
 
        tx.commit();
        session.close();
}catch(StaleStateException SSExc){
 SSExc.printStackTrace();
}catch(Exception Exc){
Exc.printStackTrace();
}finally{
    if(session != null){
    try{
    HibernateFactory.close(session);
    HibernateFactory.closeFactory();
    }catch(HibernateException ignore){
    //igonre    
    }
    }
    }
}
}

Here is the Exception stack trace
Hibernate: insert into teachers (name) values (?)
Hibernate: update students set name=? where uid=?
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:61)
at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:46)
at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:68)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:237)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:142)
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 com.oxman.test.StudentTeacherTest.main(StudentTeacherTest.java:48)



Does anybody have any idea what went wrong?

thank you

Sura

[Mark Spritzler]

It needs to insert the Student first before it can update it. I think you need to map the two relationships as one side inverse="true"

Mark

[Mark Spritzler]

Sorry I didn't realize this is a continuation or prequel to other threads created. Please stick with one thread for your issues on this Teacher Student relationship.

Thanks, closing this thread.

Mark