I've been trying to get all rows from table in EclipseLink.
I created my entities from db with the JPA tools. This is the result:
@Entity
@Table(name="employee", schema="hr")
@NamedQuery(name="Employee.findAll", query="SELECT e FROM Employee e")
public class Employee implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Integer id;
private String name;
public Employee() {
}
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
}
I found many pages where people create Query object to get all the records but they define again the "select" query like this.
Query q = em.createQuery("select e from Employee e");
But doing a research, finally I found something like this:
public List<Employee> getEmployees() {
EntityManagerFactory factory = Persistence.createEntityManagerFactory("ResourcesService");
EntityManager em = factory.createEntityManager();
Query q = em.createQuery("from Employee e", Employee.class);
return q.getResultList();
}
Is there a even more simplified way to query this, just using the class name? Because the mapped entity already contains the select query.
I mean instead of doing this
Query q = em.createQuery("from Employee e", Employee.class);
To do something like this fictional example:
Query q = em.createQuery(Employee.class);
Why not use the named query you have defined?
em.createNamedQuery("Employee.findAll").getResultList();
You could name it "Employee.class" ... :-)
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