Altered Behaviour Of Parent Triple Maps without Join Condition With Major Version 7

[tobiasschweizer]

Hi @DylanVanAssche,

I have just tried v7 release of rmlmapper and my unit tests broke ;-)

<#ProjectMonetaryAmount> a rr:TriplesMap;
  rml:logicalSource <#LogicalSourceGrant> ;

  rr:subjectMap [
    rr:termType rr:BlankNode ;
    rr:class schema:MonetaryAmount ;
    rr:template "mybn{number}_{index}"
  ] ;

...

rr:predicateObjectMap [
    rr:predicate schema:amount ;
    rr:objectMap [
       rr:parentTriplesMap <#ProjectMonetaryAmount> ;
    ]
  ] ;

The bnodes were not matching any more after switching from v6.5.1 to v7.0.0.

I could fix it by adding a join condition. In my understanding, this should not be required since the same logical source is used.

  rr:predicateObjectMap [
    rr:predicate schema:amount ;
    rr:objectMap [
       rr:parentTriplesMap <#ProjectMonetaryAmount> ;
       rr:joinCondition [
        rr:child "number";
        rr:parent "number";
      ];
    ]
  ] ;

Here are the full mapping, a test data file and the results with the non matching bnodes:

• test data: aramis_preprocessed.json
• (fixed) mapping: aramis_mapping.ttl.txt
• Wrong bnodes (no join condition in mapping): aramis_preprocessed_.ttl.txt

Maybe this is related to

Optimization for self-joins without join conditions (fixes Gitlab issue 275)

Let me know if you need more info.

Best,

Tobias

[DylanVanAssche]

This might be a result of that optimization... The spec says that it should not be needed to have a join condition with the same logical source. Thanks for the example, this should be integrated in the unittest framework so we can avoid this case in the future.