HowToDoInJavaBy

Oct 28, 2018 In this example, we've also set an initial value for the sequence, which means the primary key generation will start at 4. SEQUENCE is the generation type recommended by the Hibernate documentation. The generated values are unique per sequence. If you don't specify a sequence name, Hibernate will re-use the same hibernatesequence for different.

1. How to use em.merge to insert OR update for jpa entities if primary key is generated by database? Whether you're using generated identifiers or not is IMO irrelevant. The problem here is that you want to implement an 'upsert' on some unique key other than the PK and JPA doesn't really provide support for that (merge relies on database identity).
2. Mar 05, 2015 Introduction JPA translates entity state transitions to database DML statements. Because it’s common to operate on entity graphs, JPA allows us to propagate entity state changes from Parents to Child entities. This behavior is configured through the CascadeType mappings. JPA vs Hibernate Cascade Types Hibernate supports all JPA Cascade Types and some additional legacy cascading styles.
3. 2016-12-6  Hibernate: select max(id) from dept Hibernate: select max(id) from staff 上面这两条不用管，这个是设置了主键生成策略为increment就会发送这两句。 得到数据库表中最大的一个id值，才知道下一次要赋的id值给多少。.
4. 2017-9-2  hibernate works only with persistent entities and persistent entities are classes which are attached to any hibernate session. Please note that creating an instance of a class, you mapped with a hibernate annotations, does not automatically persist the object to the database. It must be save.

Lokesh Gupta Filed Under: Hibernate

Hibernate is an object-relational mapping (ORM) library for the Java language, providing a framework for mapping an object-oriented domain model to a traditional relational database. This means you are not required to build and execute SQL queries for interaction with database. You just have to instruct hibernate for that by calling hibernate APIs and hibernate will create and execute those SQL queries on behalf of you.

In this hibernate tutorial, I am giving example of inserting data in a single table. We have an object in application i.e. Employee. We want to store it in database. Employee class has following attributes:

• employee id – Integer
• email – String
• first name – String
• last name – String

It can have more fields, but I am taking only four to make example concrete.

1. Hibernate entity class

Hibernate talks with Java POJO classes which are marked as hibernate entities. To convert a Java class into entity, we need to apply @Entity annotation on it. There are other hibernate annotations like @Table, @Column and @Id etc which help in mapping entity fields to database table and columns.

Employee entity class looks like below after applying the annotations.

Hibernate Cascade Generated Key Insert 2017

2. Hibernate configuration

Next step is to configure hibernate in “hibernate.cgf.xml” file. This file contains all available entities in system and database connection meta-data.

3. Hibernate SessionFactory

Now hibernate configuration is on place, we have to build the hibernate session factory. Session factory is used to obtain the connection of database and various activities like commit and rollback.

4. Hibernate insert query example

Finally we will use this hibernate session factory to execute insert query to save employee in database.

Program logs.

Lets verify the data in database.

5. Troubleshooting

1. Please ensure to add hibernate and mysql driver dependencies in project. In maven these are as below:
2. Verify that hibernate.cgf.xml file is present and has valid database meta-data.

Download Source Code

Happy Learning !!

Tag: jpa,jpa-2.0,spring-data,spring-data-jpa,composite-key

Trying to save a row in a table that has a composite key (Long & Date) via Spring Data JPA. The Long part of the composite key is @GeneratedValue. But I'm getting the following error when doing a basic save() call:

The date is getting set manually prior to the save() and I've validated the sequencer exists in the database and is accessible.

Entity

@Embeddable Class

Repository Class

Any thoughts on the issue? Thanks!

It looks like you're setting the ID value to half-prepared state (Date being set but the long field to be initialized by the persistence provider, right? This means, pk is effectively non-null when the CashBatchPaymentHistoryDto instance is handed to repository.save(…). If so, this will cause an EntityManager.merge(…) being triggered, which can imagine to cause the exception as it's not going to expect to have to generate ids.

Generally speaking, if you're manually maintaining id values (even only partial ones), you have to explicitly determine the is-new-state of the entity (as this will effectively decide whether to call persist(…) or merge(…) in the JPA case). By default, this works by looking at the id field and interpreting a null value as new, non-null as not new.

In your current situation there are two options:

1. Use an @Version annotated field and leave this uninitialized before the first call to save(…).
2. Implement Persistable and its isNew() method to inspect your objects state to correctly decide whether it's new or not (in your case probably by checking (pk.cashBatchID for being null).

How to know an object has changed compared to database

java,hibernate,jpa,playframework,playframework-1.x

To force Hibernate to start a new transaction in the playframework and thus give you a new entity manager that will return the object as it is in the database and not a reference to it, you need to specifically ask the play framework to start a new transaction through...

Segregating the read-only and read-write in Spring/J2EE Apps

mysql,jpa,design-patterns,architecture,spring-data

When using MySQL, it is common for Java developers to use Connector/J as the JDBC driver (since this is the official JDBC driver from MySQL). Developers typically use the com.mysql.jdbc.Driver class as the driver, with a URL such as jdbc:mysql://host[:port]/database. Connector/J offers another driver called the ReplicationDriver that allows an...

performance of executing openjpa query

java,performance,jpa,openjpa

The problem is that you are measuring two different things.164 ms is the time that the database spent executing the query. I suspect the 824 ms that you measured is query execution + instantiation of your Entity objects.

Retrieve the id of an Entity object as soon as the entity was instantiated?

jsf,jpa

There is no way to retrieve the ID before persisting - simply because it has no ID until you persist your entity. This has nothing to do with your strategy. It has something to do with concurrence. But you can add your own temporary key for your use case: @Entity...

What are Relational Objects?

database,jpa,persistence

A Query indeed returns instances of entities, but it can also simply return arrays (i.e. rows), or lists of objects that are not entities.

JCR vs JPA for a DMS: performance, benefits, drawbacks

java,jpa,jcr,jackrabbit,dms

Short version: Documents are structured or semi-structured content. Thats THE use-case for a hierarchically organized); System.out.println('f=' + f); // -> f=Infinity // Double.MAX_VALUE = 1.7976931348623157E308 double d = Double.parseDouble('1.11111111111111E+49'); System.out.println('d=' + d); // -> d=1.11111111111111E49 ...

Can I make this request more efficient using index?

java,mysql,sql,jpa

Change the query to: SELECT ui FROM Userinfo ui WHERE twitchChannel IS NOT NULL This will benefit from an index on Userinfo(twitchChannel) (assuming there really are very few values that are filled in). At the very least, this reduces the amount of data passed from the database to the application,...

Transaction error in Spring

java,spring,jpa

In the stacktrace, there are no Spring AOP class listed between these two lines: at com.vizaco.onlinecontrol.service.impl.UserServiceImpl.saveUser(UserServiceImpl.java:51) at com.vizaco.onlinecontrol.controller.UserController.createUser(UserController.java:112) Your Dependency Injection is not setup right.. the Controller should be getting a Spring Bean of UserService ...

JPA AccessType.Property failing to retrieve value from nested classes

java,jpa,persistence

Your @Transient annotation may be causing problem here. @Transient private String href; @Transient used to indicate that perticular field should not be persisted in underlying persistance system i.e. database. you may follow this link as well ...

Not persisted entity with Hibernate

java,spring,hibernate,jpa

upd Answer, corresponding to the first version of a question was entirely removed - in short, it suggested to flush changes again after entity was updated. Current problem is in mixing two kinds of annotation - first is @ManyToOne annotation that belongs to JPA specification and second is @Cascade that...

Hibernate Query cache invalidation

java,hibernate,jpa,caching,concurrency

The query cache is not useful for write-mostly applications, as you probably figured out yourself. There is no write-through query caching option, so you need to question why you are using this feature in the first place. The entity caching is useful when you plan on changing those entities you’re...

Making an efficient query with 7 joins, JPA or SQL? What type of collection?

java,mysql,jpa,join

You say that the native SQL query runs in less than a millisecond. So stick with that. But that doesn't mean you have to wrestle with the List that comes from query.getResultList(). You can execute a native query (either from EntityManager.createNativeQuery() or from EntityManager.createNamedQuery() referring to a @NamedNativeQuery) and still...

Is it possible to have “connection preparation” with Spring / JPA persistency

java,spring,jpa,spring-data

Using AOP would seem to be one approach: an example of using AOP to enrich Spring Data repositories can be found at the below: https://github.com/spring-projects/spring-data-jpa-examples If you can get a reference to the injected EntityManager within the advice then you should be able to get the underlying connection from that...

Hibernate Cascade Generated Key Inserts

JPQL In clause error - Statement too complex

jpa,derby,jpql

Ok here is my solution that worked for me. I could not change the part generating the customerList since it is not possible for me, so the solution has to be from within this method. Bryan your explination was the best one, i am still confuse how 'in' clause worked...

Why is my EntityManager not properly injected?

jpa,ejb,wildfly,entitymanager

thanks all for help; If anyone getting the same error than me, maybe this helps: I used managed beans in JSF which are EJB, but I need to use CDI-Beans. As I deleted the Beans from the faces-config.xml everything works fine. Sorry for asking this question....

How to Fetch Data using Spring Data

spring,jpa,spring-boot,spring-data

You want to find all books for a specific author so, given an Author, retrieve all Books whose set of Authors contains the specified Author. The relevant JPQL operator is: http://www.objectdb.com/java/jpa/query/jpql/collection#NOT_MEMBER_OF_ [NOT] MEMBER [OF] The [NOT] MEMBER OF operator checks if a specified element is contained in a specified persistent...

Get id column name from POJO, using reflection

java,jpa,reflection,annotations

This is the all-by-yourself solution: public static String getPKColumnName(Class<?> pojo) { if (pojo null) return null; String name = null; for (Field f : pojo.getDeclaredFields()) { Id id = null; Column column = null; Annotation[] as = f.getAnnotations(); for (Annotation a : as) { if (a.annotationType() Id.class) id...

Unidirectional one-to-many mapping in Hibernate generates redundant updates

java,hibernate,jpa

Have you tried: @JoinColumn(name = 'parent_id', referencedColumnName = 'id', nullable = false, insertable=false, updatable=false) ...

org.hibernate.ejb.event.EJB3MergeEventListener missing after upgrading from Hibernate 3 to 4.3.9

java,hibernate,jpa,ejb

So it looks like this class (and a lot of the other EJB stuff) has been renamed and moved around. I was able to replace instances of org.hibernate.ejb.event.EJB3MergeEventListener (which was located in the hibernate-entitymanager jar in version 3.6.10) with org.hibernate.event.internal.DefaultMergeEventListener (which is actually located in the hibernate-core jar in version...

Drools Stateful Knowledge Session using persistence

java,jpa,jdbc,drools,jbpm

Finally, I have made it work. The most important mistake I was making was that I was trying to use EclipseLink as JPA provider. This approach will not work, since besides the custom persistency classes, Drools uses two other persistency-annotated classes: org.drools.persistence.info.SessionInfo and org.drools.persistence.info.WorkItemInfo. These two contain Date fields which...

Envers Pre/PostCollection Listener

java,hibernate,jpa,hibernate-envers

That's when you have persistent collections, e.g. fields of type List<String>, or Set<EmbeddedComponent>.

JPA annotation for MS SQL Server 2008 R2 IDENTITY column

hibernate,sql-server-2008,jpa,spring-data-jpa

I just found I missed setting up hibernate dialect on LocalContainerEntityManagerFactoryBean. After setting up org.hibernate.dialect.SQLServer2008Dialect as hibernate dialect, the GenerationType.IDENTITY works fine as Neil mentioned. Below is my spring data configuration and application.properties. FYI I have multiple datasource, one is H2 embedded datasource for internal use and the other is...

Optimistic locking not throwing exception when manually setting version field

hibernate,jpa,spring-data-jpa

Unfortunately, (at least for Hibernate) changing the @Version field manually is not going to make it another 'version'. i.e. Optimistic concurrency checking is done against the version value retrieved when entity is read, not the version field of entity when it is updated. e.g. This will work Foo foo =...

Configure HikariCP + Hibernate + GuicePersist(JPA) at Runtime

java,hibernate,jpa,hikaricp,guice-persist

Try removing the persistence-unit name from the JPA properties, so instead of: Map<String, String> properties = new HashMap<>(); properties.put('myJPAunit.hibernate.hikari.dataSource.url', 'jdbc:postgresql://192.168.100.75:5432/mpDb'); properties.put( + 'myJPAunit.hibernate.hikari.dataSource.user', 'cowboy'); properties.put( + 'myJPAunit.hibernate.hikari.dataSource.password', 'bebop'); you should have this: Map<String, String> properties = new HashMap<>(); properties.put('hibernate.hikari.dataSource.url',...

javax.validation.ConstraintViolationException: Bean Validation constraint(s) violated while executing Automatic Bean Validation on event:'prePersist'

hibernate,jpa,eclipselink,bean-validation,jsr303

It looks like the version isn't actually set until the entity is modified, therefore rowVersion is null when the entity is first created. That fails your 'not null' check. Try this instead and see if it works: @Version @Basic(optional = false) @NotNull @Column(name = 'row_version', nullable = false) private Long...

Hibernate's ManyToMany simple use

java,spring,hibernate,jpa,many-to-many

Change many to many mapping in CollabEntity. You need to change join table name. i.e. name from technos to some other name. @ManyToMany(cascade = CascadeType.ALL) @JoinTable(name = 'collab_technos', joinColumns = {@JoinColumn(name = 'co_id', nullable = false, updatable = false)}, inverseJoinColumns = @JoinColumn(name = 'te_id') ) ...

All I want is to access a H2 mem database in Websphere V8 using JPA 2.0

java,jpa,jdbc,websphere,persistence.xml

Found it! These full JNDI names doesn't seem to work in Websphere. I used a plain 'jdbc/sgodb' instead and it could find the context. <jta-data-source>jdbc/sgodb</jta-data-source> instead of <jta-data-source>java:comp/env/jdbc/sgodb</jta-data-source> ...

JPA NamedNativeQuery syntax error with Hibernate, PostgreSQL 9

java,hibernate,postgresql,jpa

So the problem was that em.createNativeQuery(...) was not the correct invocation of a NamedNativeQuery in order to do that I should've invoked em.createNamedQuery(...). However, seeing that em.createNativeQuery(...) does not accept @SqlResultSetMapping it is very difficult to map the result to a custom class. The end solution was to use return...

Spring 4 + JPA (Hibernate 4) + JTA transaction manager doesn't flush automatically

java,spring,hibernate,jpa,transactions

The problem is due to this property: <prop key='hibernate.transaction.jta.platform'>ch.vd.dsas.rdu.ref.transaction.jencks.JencksTransactionManagerLookup</prop> The hibernate.transaction.jta.platform property is not the same with hibernate.transaction.manager_lookup_class and it should point to an AbstractJtaPlatform implementation: <property name='hibernate.transaction.jta.platform' value='org.hibernate.service.jta.platform.internal.SunOneJtaPlatform'/> ...

jsf - foreign key in datatable

jpa,datatable

I'm happy to say I found the solution! (kudos for @Mauricio Gracia to enlight my finding-a-solution path) First, I removed the 'fetch = FetchType.LAZY' from the customer relationship in Order class @ManyToOne(cascade={CascadeType.PERSIST}) @JoinColumn(name = 'customer_id') private Customer customer; Then, I serialized the Customer class @Entity public class Customer implements Serializable...

Is possible do not fetch eager relation in JPA?

hibernate,jpa

I am not sure on this, Try specifying the fetch type explicitly in your query, some thing like this: Criteria crit = session.createCriteria(ParentClass.class); crit.add(Restrictions.eq('id', id)); crit.setFetchMode('childProperty', FetchMode.LAZY); ...

@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW) doesn't work

java,jpa,glassfish,ejb-3.0

deleteEmployee method is not wrapped into a new transaction because you are referencing method on this. What you can do is to inject reference to the facade itself and then call deleteEmployee method on it (it should be public). More or less something like this: @Stateless public class MyFacade {...

Java JPA EM.createNativeQuery(sql, someClass).getResultList()

java,jpa

An SQL query of the form 'SELECT * FROM tbl' will return each row as Object[]. Hence you should do List<Object[]> results = ... To map to a specific result class (whatever your foobar is), follow this link. You can of course just use JPQL if wanting to map to...

JPA and Apache Aries: persistence unit unresolved dependency

java,jpa,osgi,blueprint-osgi,aries

The problem was due to a fistful of missing bundles in my runtime. To solve the problem it was enough to look at the blog sample project within the Apache Aries Samples and replicate that runtime in my bnd file. The bundles I added are the following: org.apache.aries.transaction.wrappers org.apache.aries.jpa.container org.apache.aries.jpa.container.context...

Cache inconsistency - Entity not always persisted in cached Collection

java,hibernate,jpa,caching,ehcache

The Hibernate Collection Cache always invalidates existing entries and both the Entity and the Collection caches are sharing the same AbstractReadWriteEhcacheAccessStrategy, so a soft-lock is acquired when updating data. Because you are using a unidirectional one-to-many association, you will end up with a Validation table and a Step_validation link table...

OpenJPA OneToMany and composite key in parent and child table

java,jpa,jpa-2.0,openjpa

The easiest way to do this is to create an association from ChildObj to ParentObj similar to the following: @ManyToOne(fetch = FetchType.LAZY, optional = true) @JoinColumns({ @JoinColumn(name = 'serverId', referencedColumnName = 'serverId'), @JoinColumn(name = 'code', referencedColumnName = 'code')}) private ParentObj parentObj; and then define the @OneToMany association in ParentObj like...

multiple update with jpa

java,jpa

Try the following: @Override public String estadoPedido(List<DetallePedido> lista) { EntityManager em = emf.createEntityManager(); //em.getTransaction().begin(); //Consider using Container managed transactions , // if you do remove this line and the line above, and have //entity manager injected ! String mensage = null; try { for (DetallePedido ped : lista) { detPed.setPedEstado('EN...

Spring Jpa Cascade

Blocking Updating or Inserting an Entity when using Cascade in Hibernate

java,hibernate,jpa,orm,hibernate-mapping

Hibernate Cascade Generated Key Insert For Windows

If you never want to modify the EntCariHareketler, you could simply annotate it with @Immutable. If you the entity is mutable but you want to disable updates from the other side, you need to set to false the insertable and updatable @JoinColumn attribute: @OneToOne(fetch= FetchType.LAZY) @JoinColumn(name='carihareketid', insertable = false,...

Checking for multiple child constraint violations in Hibernate/JPA

spring,hibernate,jpa

I found a way to accomplish my end result, although it was through means I did not expect. In order to accomplish my goal, I would need to use nested transactions and SavePoints. At the end of the day, that implementation would still produce invalid data in my database, because...

Use alternative producers of EntityManager / EMF in integration tests

java,maven,jpa,integration-testing,cdi

After some research i found that DeltaSpike already has module called 'Test-Control', which enable use CDI in tests. So i decided to extend current EMF producer to read name of persistence unit from property file which contains configuration. Different property files in src/main/resources and src/test/resources lets me use different persistence...

Is it possible to connect a JPA implementation to a Neo4j specific version?

jpa,neo4j,datanucleus,kundera,hibernate-ogm

I have a sample app I've been playing with for a while, and was using DataNucleus v4.1 with the Neo4j it pulls in by default (2.1.3 IIRC). I just tried it with v2.0.0 and all runs fine for me. Just put the version of neo4j you want in the CLASSPATH...

JPA persit creates new existing entity in many to one relation

java,hibernate,jpa,insert

With merge you should be using: Entity entity=entityManager.merge(newEntity); int lastId=entity.getId(); to get the reference to the object and get its id where has persist does not need to because the entity is already managed after persist....

Save All

Sqlite JPA Primary Key error

java,sqlite,jpa

I don't think your second insert is colliding with the two values (secID = 1 and 2) already in the table; I think it's colliding with the value you just inserted (secID = 0). You aren't explicitly setting secID anywhere, which means it's 0. So it's inserting 0, over and...

Spring Data JPA user posts

java,spring,jpa,data

Create a second entity (java class) e.g. UserPost: @Entity @Table(...) public class UserPost { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private long id; private long userId; ... } Then add @OneToMany relationship field to User. Cascading, lazy-loading, etc. depends on how you'd use it. It'd look like this inside User: @OneToMany(cascade={...}) @JoinColumn(name='userId')...

@Resource datasource breaking DB connection

Hibernate Cascade Generated Key Insert For Word

java,jpa,jdbc,jboss,wildfly

Hibernate Types

There are a few possibilities what could go wrong. First, you are opening the connection in initParser(), but closing it in finalizeParser(), without using finally. If an exception is thrown, the connection is not closed. It would still be better to use try-with-resources. Another potential problem is that the class...