hi

I have a table named Category which has recursive bidirectional relationship . It has following fields
ID ---> Primary Key
NAME
PARENT_ID --> Foreign key referred to ID of this table
Sequence

I have done neccsary changes in the mapping file for this . But to meet my business needs, i need to fetch all the parent_id which are null (ORDERED by sequence ) I have a property named parentcategory and chilecategory in my Category POJO

public class Category {

private int id...
.....
private Category parentCategory
private set categoties
.....
public addChildCategory(Ctagory category){
.....
....
}

i wrote one sql which says
Query query = session.createQuery(from Category as c where parentCategory is null order by sequence ) .But this is throwing internal representation error . but when i tried to execute the o/p of query in toan i'm getting proper result.

can anyone help me in solving this problem . Am i missing any piece in HQL .?...

thanks
balaji

Yes, you are missing something. :)
You always have to refer to the object you want to select.

from Category as c where c.parentCategory is null order by c.sequence

Best regards
Sven

sorry i missed that in my text here .

actually i have my alias references ,as u mentioned .still i'm facing this problem .

Post the exact exception, your POJOs wiith at least all necessary attributes (where is sequence?), the HQL query you are using as well as your mappings.

the problem was actually with attribute type mismatch . I mapped a varchar2 (20) type to int .:) which was basic cause for this problem .
it has been solved now and i thank u for your eagerness .

-Balaji