JPA COUNT with composite primary key query not working
Use count(d.ertek) or count(d.id) instead of count(d). This can be happen when you have composite primary key at your entity.
jpa
How to set list of values as parameter into hibernate query?
Use setParameterList(). You’ll also have to put parenthesis around the list param. session.createQuery(“select cat from Cat cat where cat.id in (:ids)”).setParameterList(“ids”, new Long[]{1,2,3,4,5})
JPA Inheritance demands ID in subclass
I solved it myself by creating a MappedSuperclass @MappedSuperclass public abstract class EntityBase{ @Id @GeneratedValue private int id; …setter/getter } All entities are inheriting from this class. I am still wondering why the tutorials dont mention this, but maybe it gets better with the JPA 2 implementations.
Which provider should be used for the Java Persistence API (JPA) implemenation [closed]
When the Java Persistence API (API) was developed, it became popular very fast. JPA describes the management of relational data in applications using Java. JPA (Java Persistence API) is an interface for persistence providers to implement. Hibernate is one such implementation of JPA. When you use Hibernate with JPA you are actually using the Hibernate … Read more
How to prevent SQL Injection with JPA and Hibernate?
Query q = sessionFactory.getCurrentSession().createQuery(“from LoginInfo where userName = :name”); q.setParameter(“name”, userName); List<LoginInfo> loginList = q.list(); You have other options too, see this nice article from mkyong.
CrudRepository and Hibernate: save(List) vs save(Entity) in transaction [closed]
From SimpleJpaRepository: @Transactional public <S extends T> List<S> More save(Iterable<S> entities) { List<S> result = new ArrayList<S>(); if (entities == null) { return result; } for (S entity : entities) { result.add(save(entity)); } return result; } So, your second business method only shadows save(Iterable<S> entities) Crud Repository method, in the sense that it iterates the … Read more
How can I resolve java.lang.ClassNotFoundException: org.hibernate.util.DTDEntityResolver when using Spring 3.1 with Hibernate 4.0.1?
Per the Hibernate annotations 3.5 documentation:* Hibernate 3.5 and onward contains Hibernate Annotations. You should remove the dependency on hibernate-annotations, and remove the excludes from the hibernate-entitymanager dependency. Generally, you should not mix versions of dependent packages. * and JB Nizet’s comment.
Hibernate JPA: @OneToMany delete old, insert new without flush
Hibernate doesn’t know about, nor respect, all database constraints (e.g. MySQL unique constraints). It’s a known issue they don’t plan on addressing anytime soon. Hibernate has a defined order for the way operations occur during a flush. Entity deletions will always happen after inserts. The only answers I know about are to remove the constraint … Read more
How to paginate a JPA Query
For all JPA query objects (except for native SQL queries), you would use pagination through the setMaxResults(int) and setFirstResult(int) methods. For instance: return em.createNamedQuery(“yourqueryname”, YourEntity.class) .setMaxResults(noOfRecords) .setFirstResult(pageIndex * noOfRecords) .getResultList(); JPA will perform the pagination for you. Named queries are just predefined and can be cached, while other types are dynamically created. So the choice … Read more
Can a @ManyToOne JPA relation be null?
The @ManyToOne associations are optional by default, so you don’t need to set anything if you want them to be nullable. However, because you set the optional=false attribute, you made it mandatory. So instead of: @ManyToOne(optional = false, fetch = FetchType.LAZY) Set it like this: @ManyToOne(fetch = FetchType.LAZY) The optional is true by default. On … Read more