[hibernate-dev] [HSEARCH-566] Indexing null values for an @ElementCollection

[Hardy Ferentschik]

On Sun, 31 Jul 2011 21:44:13 +0200, Sanne Grinovero <sanne at hibernate.org>  
wrote:


> In case you would have a
>
> @ElementCollection
> @Field(indexNullAsl="nullToken")
> String[] tags
>
> having the value {"A","B",null}
>
> I would expect this to be encoded in the index with three field
> writes, all named "tags", and having values "A", "B", "nullToken".

+1

> But what if the array value is null by itself?
>
> Personally I would expect it to *not* write anything, not encode the
> "nullToken" which is reserved for an element being null: not having
> the collection itself means in my opinion that there are no elements,
> being similar as having an empty collection.

+1
I think in combination w/ @ElementCollection the @Fiels annotations tells
you what do to with the elements of the array/collection not the  
array/collection
itself.


> An alternative way could be to write the "nullToken" in both cases,
> but I'm not liking this much as it would imply that the item will
> match for a search similar to "all items having a null tag", while in
> fact it had no tags at all.

I don't like this approach either.


> I'd avoid adding more options as it would need a new annotation, or
> adding options to other annotations which only apply in this case.
> What do others think?

Are you talking about some sort of @ElelemntCollectionField (w/ the same  
semantics as
@Field, but limited for the usecase of element collections?
Adding such an annotation would reduce ambiguities imo, but of course  
there would be
one more annotation. Are there any other disadvantages?


--Hardy