Support `COUNT` queries (and aggregations in general)
ali1k opened this issue · comments
Hi there,
I am trying to use the LDF client and listening to data event.
As I understood I cannot send aggregate queries like 'Count' directly. I am looking for a solution to get the total number of triples from my query. I already see it in the debugger but cannot access the value!
Could you please advise me how to get the total number of triples on client request?
p.s. I am adding support for LDF to http://ld-r.org
@RubenVerborgh fyi, this count feature was also asked by @coreation for an in-house project.
Hi Ali,
Basically, COUNT still needs to be implemented in the client, and this involves implementing aggregations. It's possible, we just haven't gotten round to it.
As @mielvds says, we also have internal incentives to do so, so this will be on the agenda in the near future.
Very intrigues by ld-r.org, great that you're adding LDF support. Keep us updated, and we'll list it at http://linkeddatafragments.org/data/.
Best,
Ruben
thanks for your swift response. I am looking forward to see the support for aggregate functions on LDF-client. In the meantime, I will try to simply use the LDF server 'void:triples' with simple triple patterns.
Great! Just note that void:triples might be approximate, so you might have to be careful.
This project has now been deprecated in favor of Comunica, where this feature is supported.