The new behaviour is the followings: AllocationSize is a range of primary key values reserved for Hibernate. And the select seq.nextval from dual will be done only after hibernate consumed this range of primary keys. So you must declare the same value on both allocationSize (Hibernate) and sequence increment by (DB) When explicitly set allocationSize=500, … Read more
My bible for JPA work is the Java Persistence wikibook. It has a section on unidirectional OneToMany which explains how to do this with a @JoinColumn annotation. In your case, i think you would want: @OneToMany @JoinColumn(name=”TXTHEAD_CODE”) private Set<Text> text; I’ve used a Set rather than a List, because the data itself is not ordered. … Read more
This criteria set-up should do the trick: CriteriaBuilder cb = entityManager.getCriteriaBuilder(); CriteriaQuery<Employee> q = cb.createQuery(Employee.class); Root<Employee> root = q.from(Employee.class); q.select(root); List<String> parentList = Arrays.asList(new String[]{“John”, “Raj”}); Expression<String> parentExpression = root.get(Employee_.Parent); Predicate parentPredicate = parentExpression.in(parentList); q.where(parentPredicate); q.orderBy(cb.asc(root.get(Employee_.Parent)); q.getResultList(); I have used the overloaded CriteriaQuery.where method here which accepts a Predicate.. an in predicate in this case.
There are several way to solve it: As described in Do I need <class> elements in persistence.xml?, you can set hibernate.archive.autodetection property and Hibernate should be able to look up all annotated classes from classpath. However, that’s not JPA spec compliant. If you are using Spring, from Spring 3.1.2 (or probably even a bit earlier), … Read more
Take a look at this answer. Basically, JPA specification mandates that a removed entity becomes managed again if the persist operation is applied to it. To verify that this is really happening, enable the trace log level for org.hibernate package and search for log entries like: un-scheduling entity deletion … To avoid any unpredictable behaviour, … Read more
Specification says that derived entity should be the owning side of the relationship: 2.4.1 Primary Keys Corresponding to Derived Identities The identity of an entity may be derived from the identity of another entity (the “parent” entity) when the former entity (the “dependent” entity) is the owner of a many-to-one or one-to-one relationship to the … Read more
Maybe the following extract from the Chapter 23 – Using the Criteria API to Create Queries of the Java EE 6 tutorial will throw some light (actually, I suggest reading the whole Chapter 23): Querying Relationships Using Joins For queries that navigate to related entity classes, the query must define a join to the related … Read more
A query of type MyEntity is going to return MyEntity. You want a query for a Long. CriteriaBuilder qb = entityManager.getCriteriaBuilder(); CriteriaQuery<Long> cq = qb.createQuery(Long.class); cq.select(qb.count(cq.from(MyEntity.class))); cq.where(/*your stuff*/); return entityManager.createQuery(cq).getSingleResult(); Obviously you will want to build up your expression with whatever restrictions and groupings etc you skipped in the example.
according to the book “Pro EJB 3 Java Persistence API” Constructor Expressions A more powerful form of SELECT clause involving multiple expressions is the constructor expression, which specifies that the results of the query are to be stored using a user-specified object type. Consider the following query: SELECT NEW example.EmployeeDetails(e.name, e.salary, e.department.name) FROM Employee e … Read more
I had the same issue and it was fixed by putting the Model and Model_ class into the same package.