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Unable to update a record via Hibernate

I am able to successfully create and insert entries in a table via Hibernate, however for some reason my update method appears to not be working.
For my table, I chose to use Java annotations in the POJO file to create it.
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
/**
*
* #author
*/
#Entity
#Table(name="student") //name of DB table that will be created via Hibernate
public class Student {
#Id //Primary Key
#Column(name = "id") //map to column
private Integer id;
#Column(name = "name")
private String name;
#Column(name = "marks")
private Integer marks;
public Student(Integer id, String name, Integer marks) {
this.id = id;
this.name = name;
this.marks = marks;
}
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;
}
public Integer getMarks(){
return marks;
}
public void setMarks(Integer marks) {
this.marks = marks;
}
#Override
public String toString() {
return "Student: " + this.getId() + " | " + this.getName() + " | " + this.getMarks();
}
}
As aforementioned, the table is successfully created in a MySQL database. However, I am unable to update an objects Marks (grade) via my HQL query:
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
/**
*
* #author
*/
public class HibernateModuleTen {
private static SessionFactory factory = new Configuration()
.configure("hibernate.cfg.xml")
.addAnnotatedClass(Student.class)
.buildSessionFactory();
public static void main(String[] args) {
Session newSession = factory.getCurrentSession();
try {
/*Create Student Objects
in Memory
*/
Student student1 = new Student(100, "Greg", 95);
Student student2 = new Student(101, "Mary", 91);
Student student3 = new Student(102, "Sidi", 90);
Student student4 = new Student(103, "Rokia", 92);
Student student5 = new Student(104, "Abdel", 88);
Student student6 = new Student(105, "Christine", 77);
Student student7 = new Student(106, "Hamma", 90);
Student student8 = new Student(107, "Ahmadu", 68);
Student student9 = new Student(108, "Halimatu", 96);
Student student10 = new Student(109, "Iziren", 99);
//Begin transaction
newSession.beginTransaction();
//Save all the students
newSession.save(student1);
newSession.save(student2);
newSession.save(student3);
newSession.save(student4);
newSession.save(student5);
newSession.save(student6);
newSession.save(student7);
newSession.save(student8);
newSession.save(student9);
newSession.save(student10);
newSession.getTransaction().commit();
//Update a Student Record
updateStudent(107, 34);
//Delete a record if marks are less than 35 and then update Database
deleteStudent();
//Print all records
newSession = factory.openSession();
newSession.beginTransaction();
Criteria newCriteria = newSession.createCriteria(Student.class);
List<Student> students = newSession.createQuery("from Student").list(); //.list is .getResultList in later versions of Hibernate
for (Student aStudent : students) {
System.out.println(aStudent.toString());
}
newSession.getTransaction().commit();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
factory.close();
}
}
public static void updateStudent(Integer id, Integer marks) throws HibernateException {
/*Update Transaction*/
Session newSession = factory.openSession();
newSession.beginTransaction();
Student studentToUpdate = (Student)newSession.get(Student.class, id); //Choose record 107 to update
//Update the marks of Student based on ID and marks
studentToUpdate.setMarks(marks);
newSession.update(studentToUpdate);
//Commit to the Transaction
newSession.getTransaction().commit();
newSession.close();
}
public static void deleteStudent() throws HibernateException {
Session newSession = factory.openSession();
newSession.beginTransaction();
newSession.createQuery("delete from student s where smarks < 35")
.executeUpdate(); //Used for updates and deletes
newSession.getTransaction().commit();
newSession.close();
}
}
The update method effectively takes one of the records in the table via the id column and updates the element in the marks column.

There was an issue with my delete method:
public static void deleteStudent() throws HibernateException {
Session newSession = factory.openSession();
newSession.beginTransaction();
newSession.createQuery("delete from student s where smarks < 35")
.executeUpdate(); //Used for updates and deletes
newSession.getTransaction().commit();
newSession.close();
}
If one looks closely at the query, the "delete from student" should be "delete from Student" with a capital s. Careless error.

You didn't post your errors here, but looks like your Student bean class doesn't have a default constructor which is being invoked while executing
Student studentToUpdate = (Student)newSession.get(Student.class, id);
You can try after adding a default constructor to Student class along with your custom constructor.

Updating primary key spring boot jpa

i need to update tow columns inside my table (Job this table is joint with two other tables employees and job-history)one of them is the primary key, but i get error, if someone can help!
package com.touati.org.model;
import java.io.Serializable;
import javax.persistence.*;
import java.math.BigDecimal;
import java.util.List;
/**
* The persistent class for the jobs database table.
*
*/
#Entity
#Table(name="jobs")
#NamedQuery(name="Job.findAll", query="SELECT j FROM Job j")
public class Job implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name="JOB_ID")
private String jobId;
#Column(name="JOB_TITLE")
private String jobTitle;
#Column(name="MAX_SALARY")
private BigDecimal maxSalary;
#Column(name="MIN_SALARY")
private BigDecimal minSalary;
//bi-directional many-to-one association to Employee
#OneToMany(mappedBy="job")
private List<Employee> employees;
//bi-directional many-to-one association to JobHistory
#OneToMany(mappedBy="job")
private List<JobHistory> jobHistories;
public Job() {
}
public String getJobId() {
return this.jobId;
}
public void setJobId(String jobId) {
this.jobId = jobId;
}
public String getJobTitle() {
return this.jobTitle;
}
public void setJobTitle(String jobTitle) {
this.jobTitle = jobTitle;
}
public BigDecimal getMaxSalary() {
return this.maxSalary;
}
public void setMaxSalary(BigDecimal maxSalary) {
this.maxSalary = maxSalary;
}
public BigDecimal getMinSalary() {
return this.minSalary;
}
public void setMinSalary(BigDecimal minSalary) {
this.minSalary = minSalary;
}
public List<Employee> getEmployees() {
return this.employees;
}
public void setEmployees(List<Employee> employees) {
this.employees = employees;
}
public Employee addEmployee(Employee employee) {
getEmployees().add(employee);
employee.setJob(this);
return employee;
}
public Employee removeEmployee(Employee employee) {
getEmployees().remove(employee);
employee.setJob(null);
return employee;
}
public List<JobHistory> getJobHistories() {
return this.jobHistories;
}
public void setJobHistories(List<JobHistory> jobHistories) {
this.jobHistories = jobHistories;
}
public JobHistory addJobHistory(JobHistory jobHistory) {
getJobHistories().add(jobHistory);
jobHistory.setJob(this);
return jobHistory;
}
public JobHistory removeJobHistory(JobHistory jobHistory) {
getJobHistories().remove(jobHistory);
jobHistory.setJob(null);
return jobHistory;
}
}
my controller: here when i try to look for all job in the data base it works fine, also if i try to update juste the title of the job it works fine to but in case that i try to set a new primary key for the job table it gives me error here my controller.
package com.touati.org.model;
import java.io.IOException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
#Controller // This means that this class is a Controller
#RequestMapping(path="/project") // This means URL's start with /demo (after Application path)
public class MainController {
#GetMapping(path="/job")
public #ResponseBody Iterable<Job> getAllJob() {
// This returns a JSON or XML with the users
return jobRepository.findAll();
}
#GetMapping(path="/job/{jobId}")
public #ResponseBody String getJob(#PathVariable String jobId) {
Job job = jobRepository.findOne(jobId);
try {
job.setJobTitle("manager");
job.setJobId("test1");
jobRepository.save(job);
}
catch (Exception ex) {
return "Error updating the job: " + ex.toString();
}
return "Job succesfully updated!";
}
i got this error,
Error updating the user: org.springframework.orm.jpa.JpaSystemException: identifier of an instance of com.touati.org.model.Job was altered from test to test1; nested exception is org.hibernate.HibernateException: identifier of an instance of com.touati.org.model.Job was altered from test to test1
Thank you for your help.

Altering the PK of an entity is not permitted - if you really have to do it, you should delete, and recreate it.
Reference (an older question) : JPA Hibernate - changing the primary key of an persisted object

How to save multiple objects via ArrayList in hibernate?

I have a Student entity. My idea is to collect multiple student objects in an ArrayList and save all objects from that list to the database. When do you use #ElementCollection annotation? Does it apply to situations like this?
Student:
package basic;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
#Entity
public class Student {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private String name;
public Student() {
}
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;
}
#Override
public String toString() {
return "Student [id=" + id + ", name=" + name + "]";
}
public Student(String name) {
this.name = name;
}
}
Runner:
package basic;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class Runner {
public static void main(String[] args) {
SessionFactory sessionFactory = new Configuration().configure("/basic/hibernate.cfg.xml").buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();
List<Student> students = new ArrayList<>();
students.add(new Student("Michael"));
students.add(new Student("Dave"));
students.add(new Student("Tom"));
students.add(new Student("Dinesh"));
students.add(new Student("Lakshman"));
students.add(new Student("Cruise"));
session.save(students);
session.getTransaction().commit();
session.close();
}
}
Error
Exception in thread "main" org.hibernate.MappingException: Unknown entity: java.util.ArrayList
at org.hibernate.metamodel.internal.MetamodelImpl.entityPersister(MetamodelImpl.java:620)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1596)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:104)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:668)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:660)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:655)
at basic.Runner.main(Runner.java:27)

You have to do something like this:
for(Student student : students) {
session.save(student);
}
If you want to save entity you should map it. ArrayList<> is not mapped entity. Student has mapping so you should save it separately.

#ElementCollection you should use to define relation between object - here you have nice explenation https://en.wikibooks.org/wiki/Java_Persistence/ElementCollection
To save list of object, you need to iterate by objects, something like this -> How to insert multiple rows into database using hibernate?

I would further recommend to use another Hibernate command to avoid an Out Of Memory error...
SessionFactory sessionFactory = config.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
for (int i = 0 ; i < students.size(); i++) {
session.save(students.get(i));
if (i % 100 == 0) {//a batch size for safety
session.flush();
session.clear();
}
}
transaction.commit();
session.close();
sessionFactory.close();

Fetching data from table using hibernate

I am able to persist objects in relational database using hibernate.
please look at following code.
package one;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.SecondaryTable;
import javax.persistence.Table;
#Entity
public class Customer {
#Id
private int customerId;
private String customerName;
private String customerAddress;
private int creditScore;
private int rewardPoints;
public Customer()
{
}
public Customer(int customerId,String customerName,String customerAddress,int creditScore,int rewardsPoints)
{
this.customerId=customerId;
this.customerAddress=customerAddress;
this.creditScore=creditScore;
this.customerName=customerName;
this.rewardPoints=rewardsPoints;
}
public int getCustomerId() {
return customerId;
}
public void setCustomerId(int customerId) {
this.customerId = customerId;
}
public String getCustomerName() {
return customerName;
}
public void setCustomerName(String customerName) {
this.customerName = customerName;
}
public String getCustomerAddress() {
return customerAddress;
}
public void setCustomerAddress(String customerAddress) {
this.customerAddress = customerAddress;
}
public int getCreditScore() {
return creditScore;
}
public void setCreditScore(int creditScore) {
this.creditScore = creditScore;
}
public int getRewardPoints() {
return rewardPoints;
}
public void setRewardPoints(int rewardPoints) {
this.rewardPoints = rewardPoints;
}
}
Then to save object of this class i used following class. following class creates the object of class Customer and saves that object in database then again retrieves it and prints the CustomerName property of every saved object.
package one;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class TestCustomer {
public static void main(String args[])
{
Customer cust = new Customer(13,"Sara","Banglore",9000,60);
SessionFactory factory = new Configuration().configure().buildSessionFactory();
Session session = factory.openSession();
session.beginTransaction();
session.save(cust);
session.getTransaction().commit();
session.close();
session = factory.openSession();
session.beginTransaction();
List list = session.createQuery("FROM Customer").list();
Iterator iterator = list.iterator();
while(iterator.hasNext())
{
Customer custA = (Customer)iterator.next();
System.out.println("First Name\t"+custA.getCustomerName());
}
session.getTransaction().commit();
session.close();
}
}
I executed above code quite a number of times. code is running fine. it is able to fetch all objects which are saved.
but then i used oracle toad and fired a sql statement as
Insert into Customer(CUSTOMERID,CREDITSCORE,CUSTOMERNAME,REWARDPOINTS,CUSTOMERADDRESS)
VALUES(87,4000,'Saurabh',20,'Kalwa');
record gets stored in the table but when i execute above code, i am not able to fetch this record.
one conclusion i can draw is hibernate only returns persisted objects, but still is there any other way i can get all records ?

Are you sure you have submitted the record after inserting with toad for oracle?(you can open another client and execute a select to make sure it can be fetched from sql client).
If you want to debug, you can enable the sql logging function of hibernate, and then execute the sql which hibernate generates for your query in a sql client to make sure all the records can be fetched correctly.
And some suggestions for using JPA:
Make sure the #Entity has a name value which mapping to your physical table to avoid table mapping confusion.
Use #Column(name="column") for all your fields to mapping to the physical table column to avoid confusion.

Hibernate criteria when using mapped classes

I have created an object which maps two tables in my database, the Dictionary table and the Token table. The object (class) that represents the join between these two tables is called DictionaryToken.
Here is the class:
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import org.apache.log4j.Logger;
#Entity
#Table(name="dictionary", catalog="emscribedxcode")
public class DictionaryToken {
private static Logger LOG = Logger.getLogger(DictionaryToken.class);
private Long _seq;
private String _code;
private String _acute;
private String _gender;
private String _codeType;
private String _papplydate;
private String _capplydate;
private Long _tokenLength;
private List <TokenDictionary> _token;
private int _type;
private String _system;
private String _physicalsystem;
/*
* type of 0 is a straight line insert type of 1 is a language dictionary
* entyr type of 2 is a multiple token entry
*/
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "seq")
public Long getSeq() {
return _seq;
}
public void setSeq(Long seq_) {
_seq = seq_;
}
#Column(name = "code")
public String getCode() {
return _code;
}
public void setCode(String code_) {
_code = code_;
}
#Column(name = "acute")
public String getAcute() {
return _acute;
}
public void setAcute(String acute_) {
_acute = acute_;
}
#Column(name = "gender")
public String getGender() {
return _gender;
}
public void setGender(String gender_) {
_gender = gender_;
}
#Column(name = "codetype")
public String getCodeType() {
return _codeType;
}
public void setCodeType(String codeType_) {
_codeType = codeType_;
}
#Column(name = "papplydate")
public String getPapplydate() {
return _papplydate;
}
public void setPapplydate(String papplydate_) {
_papplydate = papplydate_;
}
#Column(name = "capplydate")
public String getCapplydate() {
return _capplydate;
}
public void setCapplydate(String capplydate_) {
_capplydate = capplydate_;
}
#Column(name = "token_length")
public Long getTokenLength() {
return _tokenLength;
}
public void setTokenLength(Long tokenLength_) {
_tokenLength = tokenLength_;
}
#OneToMany (mappedBy = "dictionarytoken", targetEntity = TokenDictionary.class, cascade = CascadeType.ALL, fetch = FetchType.EAGER)
public List<TokenDictionary> get_token() {
return _token;
}
public void set_token(List<TokenDictionary> _token) {
this._token = _token;
}
public void addToToken(TokenDictionary token){
this._token.add(token);
}
#Column(name = "type")
public int getType() {
return _type;
}
public void setType(int _type) {
this._type = _type;
}
#Column(name = "physicalsystem")
public String get_physicalsystem() {
return _physicalsystem;
}
public void set_physicalsystem(String _physicalsystem) {
this._physicalsystem = _physicalsystem;
}
#Column(name = "codingsystem")
public String get_system() {
return _system;
}
public void set_system(String _system) {
this._system = _system;
}
}
Here is my problem. I can perform queries using a service with this object with no problems UNLESS I add a criteria. Here is the method which retrieves the entries
public List<DictionaryToken> getDictionaryTokenEntries(String system) {
Session session = null;
List<DictionaryToken> dictonaries = new ArrayList<DictionaryToken>();
try {
session = HibernateUtils.beginTransaction("emscribedxcode");
session.createCriteria(Dictionary.class).addOrder(Order.desc("codeType"))
Criteria criteria = session.createCriteria(DictionaryToken.class);
/*******THIS IS THE PROBLEM STATEMENT*************************/
if (system != null) {
criteria.add(Restrictions.eq("codingsystem", system));
}
/****************************************************************/
// dictonaries = criteria.list();
Order order = Order.asc("seq");
criteria.addOrder(order);
dictonaries = criteria.list();
System.out.println("Dictionaryentries = " + dictonaries.size());
// System.out.println("Dictionaries entries EVICT start...");
// for(Dictionary dic : dictonaries){
// session.evict(dic);
// }
// System.out.println("Dictionaries entries EVICT end");
} catch (HibernateException e_) {
e_.printStackTrace();
NTEVENT_LOG.error("Error while getting List of Dictionary entries");
} finally {
if (session != null && session.isOpen()) {
try {
HibernateUtils.closeSessions();
} catch (HibernateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return dictonaries;
}
When I add the criteria, I get the following error:
org.hibernate.QueryException: could not resolve property: coding system of : com.artificialmed.domain.dictionary.model.DictionaryToken
I know that it has something to do with the nature of the object which is really a join between my dictionary class and the underlying table and my token class and table.
The field codingsystem is a field in my dictionary class. I think I am suppose to use aliases but I don't know how to do this under the current circumstances. Any help would be greatly appreciated.
Elliott

This was a newbie problem. Hibernate requires the getters and setters of the models that reflect the tables to be of a specific format. The getter MUST BE get+ where name is the fieldname in the underlying table. The setter MUST BE set+ where name is the fieldname of the underlying table. And yes the first letter of Name must capitalized.