It's my first time configuring hibernate. I've read many tutorials but not sure why this is creating the wrong create table sql statement. I am using PostgreSQL as my database.
hibernate.cfg.xml
<?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.PostgreSQL9Dialect</property>
<property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
<property name="hibernate.connection.url">jdbc:postgresql://DBIP:5432/MYDB</property>
<property name="hibernate.connection.username">MYDB</property>
<property name="hibernate.connection.password">MYPASS</property>
<property name="show_sql">true</property>
<property name="hbm2ddl.auto">create</property>
<property name="show_sql">true</property>
<mapping class="MYPROJ.model.User"/>
</session-factory>
</hibernate-configuration>
User.java
package MYPROJ.model;
import javax.persistence.*;
#Entity
public class User
{
#Id #GeneratedValue
#Column(name = "id")
private int id;
#Column(name = "username")
private String username;
#Column(name = "age")
private int age;
public int getId()
{
return id;
}
public void setId(int id)
{
this.id = id;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
}
Main.java
public class Main
{
public static void main(String[] args)
{
User user = new User();
user.setId(1);
user.setAge(20);
user.setUsername("david");
SessionFactory sessionFactory;
ServiceRegistry serviceRegistry;
Configuration configuration = new Configuration();
configuration.configure();
serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
Session session = sessionFactory.openSession();
session.beginTransaction();
session.save(user);
session.getTransaction().commit();
System.out.println("Done!");
}
}
When I run the program it shows the following SQL statement for creating the table which does not work when I run the program or when I copy pasted it manually
create table User (id int4 not null, age int4, username varchar(255), primary key (id))
What am I doing wrong here?
It turned out that "user" was a reserved keyword in PostgreSQL, changing that fixed the issue.
You can tell hibernate your column name must be escaped to avoid conflicts with the database keywords. To do that, enclose the name between `. Example:
#Column(name="`user`")
Related
I'm really new to hibernate and try to understand how it works. But know I faced with the problem.
First of all, I have such mapping:
#Entity
public class Author {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
private String name;
public Author() {
}
public long getId() {
return id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
But then, when I tried to save this entitye with session.save(), hibernate showed me error like
Exception in thread "main" org.hibernate.exception.ConstraintViolationException: could not execute statement
Caused by: org.postgresql.util.PSQLException: ERROR: null value in column "id" of relation "author" violates not-null constraint
Failing row contains (null, hello!).
So I decided to notice, why hibernate doesn't increment the id automaticy and recognized that POSTGRESQL doesn't suppert annotation GenerationType.IDENTITY. So I changet it to the GenerationType.SEQUENCE. The error was gone, but entity wasn't saved.
So here's hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="connection.url">jdbc:postgresql://localhost:5432/hibernate?useSSL=false
&serverTimezone=UTC</property>
<property name="connection.driver_class">org.postgresql.Driver</property>
<property name="dialect">org.hibernate.dialect.PostgreSQL9Dialect</property>
<property name="connection.username">postgres</property>
<property name="connection.password">4122</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<mapping class="hibernate.entity.Author"/>
<!-- DB schema will be updated if needed -->
<!-- <property name="hibernate.hbm2ddl.auto">update</property> -->
</session-factory>
</hibernate-configuration>
Here's HibernateUtil.java
public class HibernateUtil {
private static SessionFactory sessionFactory;
private static SessionFactory buildSessionFactory() {
StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
.configure("hibernate.cfg.xml").build();
Metadata metadata = new MetadataSources(standardRegistry).getMetadataBuilder()
.build();
SessionFactoryBuilder sessionFactoryBuilder = metadata.getSessionFactoryBuilder();
return sessionFactoryBuilder.build();
}
public static SessionFactory getSessionFactory() {
if(sessionFactory == null) {
sessionFactory = buildSessionFactory();
}
return sessionFactory;
}
}
And here's the Main.java, where I call the hibernate functions:
public class Main {
public static void main(String[] args) {
try(Session session = HibernateUtil.getSessionFactory().openSession()) {
Transaction tx = session.beginTransaction();
Author author = new Author();
author.setName("hello!");
session.save(author);
tx.commit();
System.out.println(session.get(Author.class, 1L));
}
}
}
After program execution it prints me null and there is no entity in database:
If you know, what can be the problem, please tell me. I'd really apreciate it!
I think the reason is setter for id missing:
public long setId(long id) {
this.id = id;
}
I'm quite new to hibernate so my problem can be obvious to you. I created database in H2 Console with 3 tables (data.mv.db), insert some values and then copied it to my database folder in project path. Now I'm trying to read one of them for tests, but always have error that table not exists. I've tried to add properties to connection url like connection delay or not changing letter to upper case but still the same.
Error:
Caused by: org.h2.jdbc.JdbcSQLException: Tabela "LOGIN_DATA" nie
istnieje Table "LOGIN_DATA" not found; SQL statement: select
login_data0_.ID as ID1_0_, login_data0_.USERNAME as USERNAME2_0_,
login_data0_.PASSWORD as PASSWORD3_0_, login_data0_.FAVOURITE as
FAVOURIT4_0_ from PUBLIC.LOGIN_DATA login_data0_ [42102-192] at
org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
at org.h2.message.DbException.get(DbException.java:179) at
org.h2.message.DbException.get(DbException.java:155) at
org.h2.schema.Schema.getTableOrView(Schema.java:437) at
org.h2.command.Parser.readTableOrView(Parser.java:5371) at
org.h2.command.Parser.readTableFilter(Parser.java:1257) at
org.h2.command.Parser.parseSelectSimpleFromPart(Parser.java:1896) at
org.h2.command.Parser.parseSelectSimple(Parser.java:2044) at
org.h2.command.Parser.parseSelectSub(Parser.java:1890) at
org.h2.command.Parser.parseSelectUnion(Parser.java:1709) at
org.h2.command.Parser.parseSelect(Parser.java:1697) at
org.h2.command.Parser.parsePrepared(Parser.java:445) at
org.h2.command.Parser.parse(Parser.java:317) at
org.h2.command.Parser.parse(Parser.java:289) at
org.h2.command.Parser.prepareCommand(Parser.java:254) at
org.h2.engine.Session.prepareLocal(Session.java:560) at
org.h2.engine.Session.prepareCommand(Session.java:501) at
org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1201)
at
org.h2.jdbc.JdbcPreparedStatement.(JdbcPreparedStatement.java:73)
at
org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:289)
at
org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:145)
at
org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:171)
... 17 more
Hibernate Config:
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.h2.Driver</property>
<property name="connection.url">jdbc:h2:file:~/database/data</property>
<property name="connection.username">admin</property>
<property name="connection.password">1234</property>
<property name="hibernate.default_schema">PUBLIC</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.H2Dialect</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<mapping class="data.Login_data"/>
</session-factory>
</hibernate-configuration>
Login_data class:
#Entity
#Table(name = "LOGIN_DATA")
public class Login_data {
private int id;
private String name;
private String password;
private String values;
public Login_data() {
// this form used by Hibernate
}
public Login_data(int id, String name, String password, String values) {
this.id = id;
this.name = name;
this.password = password;
this.values = values;
}
#Id
#GeneratedValue
#Column(name = "ID")
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
#Column(name = "USERNAME")
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Column(name = "PASSWORD")
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
#Column(name = "FAVOURITE")
public String getValues() {
return values;
}
public void setValues(String values) {
this.values = values;
}
}
Main class:
public static void main(String[] args){
Login_data user = new Login_data();
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
/*session.beginTransaction();
session.save(user);
session.getTransaction().commit();*/
// now lets pull events from the database and list them
session.beginTransaction();
List result = session.createQuery("from Login_data").list();
for (Login_data event : (List<Login_data>) result) {
System.out.println(event.getName());
}
System.out.print(result);
session.getTransaction().commit();
session.close();
}
I've tried to edit configuration. So I add:
<property name="hibernate.hbm2ddl.auto">update</property>
And make empty database. What is strange is database and table created by Java after opening in H2 Console is not visible. So that can be the problem.
I wanted to put a lot of data, so how to make it not from java to be visible there?
Thanks to #JB Nizet I see my error. I was copying database to project path, where my path "~/database" shows to database in user folder, and I was copying it to project folder so I should use "./database" .
Still if I want to make runnable I would need to use user location to have it rightly working on other machines.
I have a question about my hibernate mapping, I am creating a project with Spring and hibernate, I am facing a issue that I can solve it so far and I couldn't find someone able to help me so far, so I mapped the database and did everything as expected but I am receiving this message:
HHH000183: no persistent classes found for query class: FROM com.inbox.model.Estado
My hibernate.cfg.xml is like this
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://inboxmysqldb.c4lcntgo83fr.us-west-2.rds.amazonaws.com</property>
<property name="hibernate.connection.username">inboxuser</property>
<property name="hibernate.connection.password">xxxxxx</property>
<!-- <property name="hibernate.dialect">org.hibernate.dialect.HSQLDialect</property> -->
<property name="hibernate.show_sql">false</property>
<!-- <property name="hibernate.hbm2ddl.auto">true</property>-->
<property name="hibernate.connection.pool_size">10</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Mapping files -->
<!-- <mapping class="com.inbox.model.Box"/> -->
<mapping class="com.inbox.model.Estado"/>
</session-factory>
</hibernate-configuration>
My class is mapped like this:
package com.inbox.model;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
#Entity(name="com.inbox.model.Estado")
#Table(name = "estado",
uniqueConstraints={#UniqueConstraint(columnNames={"id"})})
public class Estado implements IdentifierInterface, Serializable{
/**
*
*/
private static final long serialVersionUID = 3625863483844458267L;
#Id
#GeneratedValue(strategy = javax.persistence.GenerationType.IDENTITY)
#Column(name="id", nullable=false, unique=true, length=11)
private Integer id;
#Column(name="nome", length=20, nullable=true)
private String nome;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
}
HibernateUtil:
public class HibernateUtil {
private static SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
if (sessionFactory == null) {
Configuration configuration = new Configuration();
configuration.configure("hibernate.cfg.xml");
ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
.applySettings(configuration.getProperties()).build();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
}
return sessionFactory;
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
public static Session getSession() {
return getSessionFactory().openSession();
}
}
As requested follow the query
public T findById(int id) {
Session session = HibernateUtil.getSession();
session.beginTransaction();
try {
Query byIdQuery = session.createQuery("FROM " + entityClassName + " as c WHERE c.id = :id");
byIdQuery.setParameter("id", id);
return (T) byIdQuery.uniqueResult();
} catch (Exception e) {
throw new InboxException(e);
} finally {
session.close();
}
}
I ran out of ideas to try fix.
Thanks in advance
This question is different from the other questions on the same topic of MappingException: Unknown entity because I have this line in my hibernate config:
<mapping class="bbb.Students" />
My entity class is as follows:
package bbb;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name = "Students")
public class Students implements java.io.Serializable {
private String id;
private String name;
private String number;
#Id
#Column(name = "ID", unique = true, nullable = false)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
#Column(name = "NAME", nullable = false)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Column(name = "NUMBER", nullable = false)
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
}
I have the database test and the table Students manually created.
The error is:
org.hibernate.MappingException: Unknown entity: bbb.Students
Exception in thread "main" org.hibernate.MappingException: Unknown entity: bbb.Students
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:776)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1533)
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:682)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:674)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:669)
at bbb.App.main(App.java:39)
The Main class is as follows:
package bbb;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
public class App
{
public static void main( String[] args )
{
System.out.println("Hibernate one to one (Annotation)");
Configuration conf = new Configuration();
SessionFactory sf = conf.configure()
.buildSessionFactory(
new StandardServiceRegistryBuilder()
.applySettings(conf.getProperties())
.build());
Session session = sf.openSession();
session.beginTransaction();
Students s = new Students();
s.setId("1");
s.setName("Joe");
s.setNumber("12345");
session.save(s);
session.getTransaction().commit();
System.out.println("Done");
}
}
The full hibernate.config is as follows:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">root</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>
<mapping class="bbb.Students" />
</session-factory>
</hibernate-configuration>
Just imported your Students class in a Hibernate based project. Everything work fine. Before running the application, I created schema "test" manually. Post a class with the main method. Probably something is wrong in it.
Update:
Imported your's main method. The application still works. Can't reproduce an issue.
import bbb.Students;
import org.hibernate.*;
import org.hibernate.cfg.Configuration;
public class Main {
private static final SessionFactory ourSessionFactory;
static {
try {
ourSessionFactory = new Configuration().
configure("hibernate.cfg.xml").
buildSessionFactory();
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
public static Session getSession() throws HibernateException {
return ourSessionFactory.openSession();
}
public static void main(final String[] args) throws Exception {
final Session session = getSession();
try {
Transaction transaction= session.beginTransaction();
Students student = new Students();
student.setName("Vasua");
student.setNumber("13");
student.setId("1");
session.save(student);
transaction.commit();
} finally {
session.close();
}
}
}
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernte Configuration DTD//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="connection.url">
jdbc:mysql://localhost/stack
</property>
<property name="connection.driver_class">
com.mysql.jdbc.Driver
</property>
<property name="connection.username">
root
</property>
<property name="connection.password">
root
</property>
<!-- DB schema will be updated if needed -->
<property name="hbm2ddl.auto">update</property>
<mapping class="bbb.Students"/>
</session-factory>
</hibernate-configuration>
Although I read session.get null problems on stackoverflow and tried to do what they suggested, my problem seems to continue.
SessionFactory mysessionfactory = new Configuration().configure().buildSessionFactory();
Session mysession = mysessionfactory.openSession();
mysession.beginTransaction();
Myperson person3 = (Myperson) mysession.get(Myperson.class, 3);
System.out.println("there you go : "+person3.getName());
As simple as it seems, i am just trying to retrieve data from database. Let me show you the database.
As you can see above , the data i like to retrieve has a name !
This is what i get, NOTHING !
And finally , i run the code with debug mode and i hope you'll understand the problem and suggest a solution.
i am in a conflict here, my database shows that data which has UserId of 3 has a name but why can't i see it in my output ?
EDIT : Here is my hibernate xml file as you requested.
<?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="connection.pool.size">1</property>
<property name="hibernate.connection.url">
jdbc:mysql://localhost:3306/myhibernatedb
</property>
<property name="hibernate.connection.username">
root
</property>
<property name="hibernate.connection.password">
000003
</property>
<property name="hibernate.current_session_context_class">thread</property>
<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<!-- List of XML mapping files -->
<mapping class="org.emreverim.com.Myperson"/>
<mapping class="org.emreverim.com.Vehicle" />
<mapping class="org.emreverim.com.FourWheeler" />
<mapping class="org.emreverim.com.TwoWheeler" />
</session-factory>
</hibernate-configuration>
EDIT 2 : here is myperson class as you requested.
#Entity
public class Myperson {
#Id #GeneratedValue(strategy=GenerationType.AUTO)
private int userID;
private String name;
#OneToMany(cascade=CascadeType.PERSIST)
private Collection<Vehicle> vehicle = new ArrayList<Vehicle>();
public Collection<Vehicle> getVehicle() {
return vehicle;
}
public void setVehicle(Collection<Vehicle> vehicle) {
this.vehicle = vehicle;
}
#Lob
private String description;
#Temporal (TemporalType.DATE)
private Date joinedDate;
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Date getJoinedDate() {
return joinedDate;
}
public void setJoinedDate(Date joinedDate) {
this.joinedDate = joinedDate;
}
public int getUserID() {
return userID;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public void setUserID(int userID){
this.userID = userID;
}
}
I think the problem here is caused by the fact that Hibernate Session.get() method expects a Seriliazable id object, which is not provided in your case here mysession.get(Myperson.class, 3) .
Because the given value 3 here is of primitive type int which contains only the value and isn't serialized so you have to use new Integer() method in order to pass an Integer serializable object or new Long() to pass a Long serializable object to the get() method, so just change:
Myperson person3 = (Myperson) mysession.get(Myperson.class, 3);
To:
Myperson person3 = (Myperson) mysession.get(Myperson.class, new Integer(3));
Or:
Myperson person3 = (Myperson) mysession.get(Myperson.class, new Long(3));
We happened to see the solution, my database has been configured as utf-16 while it should have been utf-8. so its just as simple as that. i gave thumps up for all answers, thanks for all of your concerns.
In your entity map you forgot to add the annotations #column attributes to the field and #table to link it to the table.
Example:
#Column(name="description")
private String description;
Check this example for the annotations http://archive.oreilly.com/pub/a/onjava/2007/02/08/an-introduction-to-hibernate-3-annotations.html?page=2