I'm starting with JPA in netbeans and I set out to create a small maintainer of a course (school). I found a problem in obtaining a group of students according to the course, I have not given how to introduce the clause "where" or some grouper to save the records in a list:
public List<Alumno> alumnos(String curso){
List<Alumno> a = ejbFacade.findAll();
return a;
}
Could someone give me an idea of how to do it?
Query query = entitymanager.createQuery("select * from alumnos where nombre = :nombre");
query.setParameter("nombre", 'Jose');
List<String> list=query.getResultList();
Another way would be to create with @NamedQuery, the query you define in the entity
@Entity
@Tabel("alumnos")
@NameQuery("select * from alumnos where nombre = :nombre", name="buscar por nombre")// es un ejemplo
pulic class Alumno{
@Id
@GeneratedValue
private Long id;
@Column
private String nombre;
}
and then you can do the following
Query query = entitymanager.createNamedQuery("buscar por nombre");
query.setParameter("nombre", 'Jose');
List<String> list=query.getResultList();