Hi,

I have a class structure like this
public class Product
{
private productId;
private ProductUse productUse
....
}
public class ProductUse
{
private Set useCategories = new HashSet //Collection of Category
.....
}
public class Category
{
private long categoryId; //primaryKey
private CategoryHead categoryHead;
....
}
public class CategoryHead
{
private long categoryHeadId; //Primary key
....
}

I want to fetch a Product with given productId and categoryHeadId.
I am able to get it by using the below query,
" from Product product where product.productId= :productId
and product.ProductUse.useCategories.categoryId.categoryHead.categoryHeadId :categoryHeadId

But getting error using the query
" from Product product where product.productId= :productId
and product.ProductUse.useCategories.categoryHead.categoryHeadId :categoryHeadId
this gives error saying invalid property 'categoryHeadId'

Anybody can explain how it works in first case(By introducing categoryId) and not in second case ?

Is there any other better way to do this?

Thanks,
Sony M

OR