Page MenuHomePhabricator

New constraint: properties with identical values
Open, Needs TriagePublic

Description

Some Wikidata properties are expected to hold the same values when they are both present on the same item. This is the case for https://www.wikidata.org/wiki/Property:P4285 and https://www.wikidata.org/wiki/Property:P269 for instance (see https://www.wikidata.org/wiki/Q334065#P4285 and https://www.wikidata.org/wiki/Q334065#P269 for an example). These two properties are used to link to different databases which use a shared identifier.

The question of whether this is the desired way to link to two databases which share a common identifier is still being debated (see https://www.wikidata.org/wiki/Wikidata:Property_proposal/Directory_of_Open_Access_Journals_ID and https://www.wikidata.org/wiki/Wikidata:Property_proposal/Plants_of_the_World_online for instance).

The issue with this approach is that it creates some redundancy. One possible way to help with that redundancy would be to have a constraint that would enforce equality of these values on a given item. This constraint would be useful for existing properties which have this redundancy issue and potentially for others if we decide to use this solution in other cases.