one-to-one id without fetching

delone · **Joined:** Mon Feb 02, 2009 8:56 am **Posts:** 6

Hi:

I've got two related classes as shown here:

Employee ------> Photograph

Every employee has got a photo. It's a one-to-one association set to "Fetch.LAZY", because I don't want the photograph to be retrieved every time I get information about an employee.

Sometimes I need an employee's photo id (or null, if none), but I still don't want to retrieve the whole image.
So I do "myEmployee.getPhotograph().getId()" but I can see Hibernate is querying the database and selecting Photograph table to load the photo and give me the id. But, as the id is already in the Employee table (used by joinColumn), isn't it possible to avoid hitting the database for the photo? I just want the id!

Thanks in advance.

mmerder · **Posted:** Mon Feb 02, 2009 9:21 am

Could you provide your mapping and the code where you access it?

delone · **Joined:** Mon Feb 02, 2009 8:56 am **Posts:** 6

mmerder wrote:

Could you provide your mapping and the code where you access it?

This is my Employee class:

Code:

@Entity
public class Employee {
...

@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "idPhotograph")
private Photograph photo;
...

My Photograph class:

Code:

@Entity
public class Photograph {
...
}

Code where I'm accessing it:

Code:

...
Employee emp = EmpService.find(id);
System.out.println("Photo id: " + emp.getPhotograph().getId());

mmerder · **Posted:** Mon Feb 02, 2009 9:31 am

I also faced this problem. You need to annotate your getters instead of your fields. Only when you annotate your getters, hibernate knows, which one is the id-getter and so does not initialize a proxy. Notice that it's not enough just to annotate one specific getter, but annotate all getters instead of fields within a class.

delone · **Joined:** Mon Feb 02, 2009 8:56 am **Posts:** 6

mmerder wrote:

I also faced this problem. You need to annotate your getters instead of your fields. Only when you annotate your getters, hibernate knows, which one is the id-getter and so does not initialize a proxy. Notice that it's not enough just to annotate one specific getter, but annotate all getters instead of fields within a class.

Yes, you're right, it works ;-)

Thank you very much