querying for the property named 'id'

PawelMiniewicz · **Joined:** Mon Dec 05, 2005 8:13 am **Posts:** 9

I have an entity that has property named id that is not a primary key.

Code:

class Example
{
  @Id
  Integer getKey();

  @Basic
  Integer getId();
}

I need to query for an object with a given id property (say: id=5) and I do it like this.

Code:

manager.createQuery( "select e from Example e where e.id = :id").setParameter( "id", 5).getResultList();

But this query will return an object with property key = 5. I found in docs that keyword id in HQL always means entity's primary key. But how to write query that uses id property that is not a key?

emmanuel · **Posted:** Tue Feb 21, 2006 10:38 am

id is a keyword in HQL because Hibernate support more features than EJB3.
We'll need to fix that regarding EJB3.

Note that calling a non id property "id" while having an id property not called id is a bit schizophrenic and errorprone.

PawelMiniewicz · **Joined:** Mon Dec 05, 2005 8:13 am **Posts:** 9

emmanuel wrote:

Note that calling a non id property "id" while having an id property not called id is a bit schizophrenic and errorprone.

I agree, but this is an extraordinary case: I must implement some interface which defines method 'getId', so I cannot rename it.

Is there any way to rewrite my query in hql to return the results I'm expecting?

I know I can write a native sql query that would return the real id and then fetch my entity with hql, but I don't like this solution.

emmanuel · **Posted:** Tue Feb 21, 2006 12:10 pm

Not with HQL, sorry.
Try CriteriaQuery or Native query

max · **Posted:** Tue Feb 21, 2006 12:41 pm

so this is totally untested, but might work with a little known feature called "noop":

Code:

<id>...</id>
<property name="id" column="theidcolumn"/>
<property name="alternativeId" access="noop" column="theidcolumn" insert="false" update="false"/>

this *might* allow you to do:

Code:

manager.createQuery( "select e from Example e where e.alternativeId = :id").setParameter( "id", 5).getResultList();

it is a *workaround* that should only be used until we get the "id" hiding feature solved in the ejb3 handling.

PawelMiniewicz · **Joined:** Mon Dec 05, 2005 8:13 am **Posts:** 9

OK, I see, but is it possible to do it with Annotations?
I don't see any property like 'access' in @Column

BTW, I solved the problem with native query. Thanks for your time
Pawel

max · **Posted:** Tue Feb 21, 2006 5:39 pm

no, not possible with annotations afaik.

emmanuel · **Posted:** Tue Feb 21, 2006 7:49 pm

This is doable through annotations

@AccessType("noop")
@Column(name="id", insertable=false, updatable=false)
private property String getAlternativeId()

max · **Posted:** Wed Feb 22, 2006 1:58 am

wow there is a hack ;) fun.

PawelMiniewicz · **Joined:** Mon Dec 05, 2005 8:13 am **Posts:** 9

Just for the record: I tested the solution with @AccessType and it does work. Thanks