jpa

Java AppEngine: JDO or JPA, How to choose??

Pros and Cons of choosing JDO or JPA for a Grails Application that will run on Google AppEngine ...

Rolling back foreign key relationships with Hibernate

What is the Hibernate best practice when having to roll back foreign key relationships, but not wanting to throw out the transaction (ie. still proceed with saving other data)? If I just pass the exception back up the stack or don't do this rollback, then I will hit an error when I do try to save the other data (Null or Transient Object...

JPA, How to use the same class (entity) to map different tables?

I have two tables: Ta and Tb. They have exactly the same table structure but different table names. I try to create one entity class to map the table structures. Some of my common application modules will use this entity class to dynamically query and update either Ta or Tb based on parameters. Can it be done in JPA? How can I write ...

OneToOne relationship with shared primary key generates n+1 selects; any workaround?

Imagine 2 tables in a relational database, e.g. Person and Billing. There is a (non-mandatory) OneToOne association defined between these entities, and they share the Person primary key (i.e. PERSON_ID is defined in both Person and Billing, and it is a foreign key in the latter). When doing a select on Person via a named query such as: ...

Grails Ignoring @Id Annotation

I'm trying to use an existing database with Grails. My DataSource.groovy starts with this: import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsAnnotationConfiguration dataSource { configClass = GrailsAnnotationConfiguration.class pooled = true driverClassName = "com.mysql.jdbc.Driver" username = "root" password...

Using Different Hibernate User Types in Different Situations

I am using Hibernate + JPA as my ORM solution. I am using HSQL for unit testing and PostgreSQL as the real database. I want to be able to use Postgres's native UUID type with Hibernate, and use the UUID in its String representation with HSQL for unit testing (since HSQL does not have a UUID type). I am using a persistence XML with dif...

JPA/Hibernate Query Returns Stale Results

I am using an EXTENDED Persistent Context because it will allow me to Lazily Load a one-many relationship on an object and it also won't require a SELECT before I "merge" an object with the persistent context. I have an DummyObject with: A "Last Updated" Date Field A One-Many Relationship This Object is being updated every 5 seconds...

Is it feasible and or recommended to support two JPA implementations?

We have an app that we are developing and we are considering supporting two different JPA implementations. At the moment we are using openjpa and have fairly well tested code. I swapped in toplink, ran the tests, and found a bunch of failures. You'd think that because JPA is a standard there shouldn't be any differences! The rational...

Hibernate Query Hints for JPA

I have been trying to find a definitive resource for all of the hints that can be set through the Query.setHint(String,Object) method call in JPA, but I am coming up empty. Anyone know if a good reference? ...

Ant task for generating ER diagram from JPA/Hibernate annotated classes

Does anyone know of a tool that can do that? Linguine maps seems to only work on old hibernate xml files. And the hibernate tool task hbm2hbmxml seems to have a bug so that I can't do the two step process "annotations->hbmxml->diagram" Best, Anders ...

Why does EclipseLink think my database schema doesn't exist?

I'm working on a web project using EJB 3.0, and whenever EclipseLink tries to interact with the database, it says that the schema I'm using doesn't exist (which it does). I get a massive, unhelpful stack trace from GlassFish 2.1, which begins with: EclipseLink, version: Eclipse Persistence Services - 1.1.0.r3639-SNAPSHOT file:/C:/Docu...

what the heck is a JPA configuration?

I'm going nuts trying to get a simple Envers example to work. I'm stuck on the org.hibernate.tool.ant.EnversHibernateToolTask it looks like I finally got all the jar files I needed, but now I get the error message [hibernatetool] Persistence unit not found: 'ConsolePU'. BUILD FAILED C:\deka\proj\java\test-database\build.xml:61: Persi...

Empty constructors and setters on JPA Entites

Hi! I don't like the requirement on have at least one empty constructor and public setters on JPA entities. While I understand the issue on the EntityManager side, this invalidates class invariants. Does anyone have a solution for this (design pattern or idiom level) ? Thanks! Igor ...

Hibernate query (not SQL) logging

I'm using Hibernate's EntityManager as a JPA implementation. What I want is logging of the query (HQL or JPA Query Language) made to EntityManager. This is different than SQL logging (which is enabled with the hibernate.show_sql property). My application issues several queries to Hibernate. I want logging of both the queries issued to H...

A class that behaves like @Entity and @Embeddable

Hi, I have a one way @OneToMany relationship between a Team and Player class. I would like to save a Team object among your Players. Player's identifier IS COMPOUND by Team foreign key and list index as follows. I have a mapping like this one because i need to save Team and your Players ate the same time. @Entity public class Team { ...

What is the proper JPA mapping for @Id in parent and unique sequence in base classes

I have a class hierarchy: abstract DomainObject { ... @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator="SEQ") @SequenceGenerator(name="SEQ",sequenceName="SEQ_DB_NAME") @Column(name = "id", updatable = false, nullable = false) private Long id; ... } BaseClass extends DomainObject { ... // Fill in ...

Can I put annotations for multiple processors into a Java class?

I'm not really sure how annotations actually work. I'm using JAXB and JPA (with eclipselink) on the same classes, i. e. I get class definitions like this: @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "Channel") @Entity public class Channel extends NamedEntity { @XmlAttribute @XmlSchemaType(name = "anyURI") @Column(n...

JPA/Hibernate: code based validation of jpa queries.

What is the right way do validate a jpa query programmatically. Hibernate validates all annotation based named queries on entities. But how can I call this validation routine on programmatically builded jpa queries, to check for errors? @Entity public class Foo { @Id public int id; public String name; } main(...) { Query q = ...

bidirectional hibernate relationship

hi, i have a webapplication, using hibernate and the following entities. What do I wrong: ... @Entity public class Registration implements BaseEntity { ... @OneToMany(cascade = {CascadeType.PERSIST}, mappedBy = "registration", fetch = FetchType.EAGER) private List<OrderedProduct> orderedProducts = new ArrayList<OrderedProduct>(); ... pu...

Is there a way to change the JPA fetch type on a method?

Is there a way to change the JPA fetch type on a single method without editing the entity object? I have a shared ORM layer consisting of JPA entity classes. This ORM layer is accessed by two DAO layers. One DAO needs lazy fetching, as it is for my web application, the other needs eager fetching, as I need it to be threadsafe. Here is ...