riccardotommasini/calcite-ontop

Test Project for Ontop-Calcite Integration

Hi there 👋

calcite-ontop's Issues

Different Query Expansion Calcite/Native DB

@@tbox is fixed to exampleBooks.owl
Query is fixed to : PREFIX : http://meraka/moss/exampleBooks.owl# SELECT ?x WHERE { ?x a :Book }

Ontop Expansion with Postgres/MySQL or with calcite handling the jdbc communication is different.

Which one is correct?

ontop-expasion-calcite.txt
ontop-expasion-mysql.txt
ontop-expasion-postgres.txt

Simple Query executed from ontop though calcite

I simplified the problem in order to make it run.
Since there are some issues with UNION and Calcite and Ontop most likely has a bug in the query expansion as I noted in another issue.

The main problem was related to the connection used for the querying, which in Ontop (Quest) is different for metadata retrieval (localConnection) and query execution (conn)

Currently, I do the setup twice. I should point out this problem to the ontop guys so that we can optimize it.

The query:
PREFIX : http://meraka/moss/exampleBooks.owl#
SELECT ?x WHERE { ?x a :Book }

the mapping:

[PrefixDeclaration]
: http://meraka/moss/exampleBooks.owl#
owl: http://www.w3.org/2002/07/owl#
rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns#
xsd: http://www.w3.org/2001/XMLSchema#
rdfs: http://www.w3.org/2000/01/rdf-schema#
quest: http://obda.org/quest#

[SourceDeclaration]
sourceUri datasource1
connectionUrl jdbc:calcite:
username root
password mysql
driverClass org.apache.calcite.jdbc.Driver

[MappingDeclaration] @collection [[

mappingId cl_Books
target :book/{bk_code}/ a :Book ; :title {bk_title} .
source select "bk_code", "bk_title" from "tb_books"

]]