Dynamic select within query not working.
Any insights or help would be greatly appreciated.
I have to pass a list of lists in the format below. Hundreds of them which is why I'm trying to iterate in a single query.
Please explain why accessing element 0 within the row data works here:
g.inject([['2011-12-01', 3873], ['2023-12-02', 3946], ['2023-12-03', 3997]]).
unfold().as('row').
coalesce(
select('row').limit(local, 1).unfold()
)
But nesting the select within the query to return a matching Vertex does not:
g.inject([['2011-12-01', 3873], ['2023-12-02', 3946], ['2023-12-03', 3997]]).
unfold().as('row').
coalesce(
__.V().hasLabel('UsdValue').has('date', select('row').limit(local, 1).unfold())
)
Ultimately trying to create an if/then exists query but I can't get it to even match.
Solution:Jump to solution
Sorry it took a while for someone to get to this. I think your problem here is that you are trying to use
has(String, Traversal) in __.V().hasLabel('UsdValue').has('date', select('row').limit(local, 1).unfold()) but it doesn't work the way you expect. basically, the result of the traversal you give to has() is not given as the value to the comparator. More generally, P does not take a Traversal making any such usage impossible. It is designed to work such that the value of "UsdValue" i...1 Reply
Solution
Sorry it took a while for someone to get to this. I think your problem here is that you are trying to use
has(String, Traversal) in __.V().hasLabel('UsdValue').has('date', select('row').limit(local, 1).unfold()) but it doesn't work the way you expect. basically, the result of the traversal you give to has() is not given as the value to the comparator. More generally, P does not take a Traversal making any such usage impossible. It is designed to work such that the value of "UsdValue" is given to your Traversal argument and if that returns a value the filter is found to be true. We document this in the Reference Documentation at https://tinkerpop.apache.org/docs/current/reference/#has-step and have a more detailed account here: https://tinkerpop.apache.org/docs/3.7.1/recipes/#_has_and_traversal_arguments