Question

I have @ManyToOne relation in object and in the “one” side i don’t have a @OneToMany relation how can i can add the @IndexColumn in this situation?
And can i add @indexColumn in @ONeToOne relation?

Answer 1

Your question doesn’t make much sense. IndexColumn is used to assign indices to the elements of a List, in a OneToMany or ManyToMany association. You just have a ManyToOne association, so there’s no list at all, so there is no need for an index column.

I could imagine you would want to execute a query returning all the children of a parent, and want them placed in a list at a specific index. In this case, you need to add a persistent index field to your child entity, execute the query, sort the children by index, and then create the indexed list by yourself:

List<Child> sortedList = 
    session.createQuery("select c from Child c where c.parent = :parent order by c.index")
           .setParameter("parent, parent)
           .list();
List<Child> indexedList = new ArrayList<Child>();
for (Child child : sortedList) {
    indexedList.ensureCapacity(child.getIndex() + 1);
    indexedList.set(child.getIndex(), child);
}

For OneToOne associations, IndexColumn really doesn’t make any sense.