Hibernate version: 1.2.0 - alpha


Hi all,

I am trying to map a self join type relation (1-2-1) mapping as described below, but it doesn't appear to work.

Here's a piece of snippet.

I have a table

Task
(Task_Id number,
Name varchar,
Refers_to number,
Depends_on Number);

the relation is like this

Task__Name ______Refers_To__Depepends_on
1.........Make Coffee................null...............null
2.........Drink Coffee................null............... 1
3.........Make milky coffee........ 1................. 1
(... and so on)

This is just to illustrate that Refers_to and Depends_on are the "Task ID" itself

Now, in the class, i have the following definition

class Task
{
private int taskId;
private string name;
private Task refersTo;
private Task dependsOn;
//corresponding getters and setters here....
}

in the mapping file, i have the following for the two properties:

<one-to-one name="RefersTo" class="mynamespace.Task, myAssembly" />

note: I tried putting in foreign-key as "Task_ID", tried changing it to "REFERS_TO" and so on...

There are no errors in loading and running the app, but when I try saving, the Task gets saved as normal, but if any Task is set to REFERS_TO or DEPENDS_ON is not saved. They are saved as NULL (always)

When loading, the two properties (Task.RefersTo and Task.DependsOn) point to the class itself.

i.e. If I load ID=1
the I get

Task t = LoadWithID(1);
the corresponding values are...

t = Make Coffee
t.RefersTo = Make Coffee
t.DependsOn = Make Coffee.

I don't know why these are being set.

Pleas let me know if I have made any mistake or if this is any known issues.

Many thanks
Sath

That's because what you have is not one-to-one. What you have is a many-to-one association and you should map it using <many-to-one name="RefersTo" column="Refers_to" />.

many thanks

This worked. It was my mistake indeed! Being a newbie sucks!!! ;)

Once again, I appreciate all your help.