Hello!
I have got a question on querying vs. filtering with cross-references…
In our database, we have three data classes: Chunk, Document, and Corpus.
Corpora contain Documents, which is stored by the documents having a corpus property that cross-references the Corpus object they belong to.
Likewise, Documents contain Chunks, which is again stored by chunks having a document property that cross-references the Document object they belong to.
Cross-reference scheme: Chunk → Document → Corpus
When querying chunks, I would like to retrieve fields for the chunks themselves as well as fields of the cross-referenced document and the corpus that this document cross-references, that is, from a chunk object I would like to follow the path:
["document", "Document", "corpus", "Corpus", "source"], where source is a property of class Corpus.
This works fine when filtering using exactly this value given here for path.
# Get all chunks for the corpus
where_clause = {
"path": ["document", "Document", "corpus", "Corpus, "id"],
"operator": "Equal", "valueText": corpus_id
}
However, I am only able to get properties of the cross-referenced Document object but not of the further cross-referenced Corpus object when querying chunks like this:
result = self.client.query \
.get(class_name="Chunk",
properties=[
"text",
"document {... on Document {url}}",
"document {... on Document { corpus {... on Corpus {source}}}}"
]) \
.with_near_vector({"vector": query_vector}) \
.do()
The result always contains the url property from the cross-referenced Document object, but not the source property from the nested cross-referenced Corpus object. Instead, I get a corpus property with a null value back:
'document': ['corpus': None, 'url': 'https://myurl.com/'}].
Since filtering seems to work fine with these multi-level cross-references, I figure it should also work with querying. However, I have found no way to get it to work. The syntax validation of the property string basically tells me that document {... on Document { corpus {... on Corpus {source}}}} is well-formed (and everything else I tried is not). I am not excluding that I am just using the wrong syntax or approach but I also did not find any hints in the Weaviate documentation.
Would it be a possible solution to add a raw query using .with_additional?
Thank you very much for any help or feedback!
