Using refs

[denisnazarov]

How does one use refs to other objects?

Example: https://github.com/MuseumofModernArt/collection has an Artists.json and Artworks.json. Artworks reference objects in Artists via an array of ConstituentID:

{
  "Title": "Ferdinandsbrücke Project, Vienna, Austria, Elevation, preliminary version",
  "Artist": [
    "Otto Wagner"
  ],
  "ConstituentID": [
    6210
  ],
  "ArtistBio": [
    "Austrian, 1841–1918"
  ],
  "Nationality": [
    "Austrian"
  ],
  "BeginDate": [
    1841
  ],
  "EndDate": [
    1918
  ],
  "Gender": [
    "Male"
  ],
  "Date": "1896",
  "Medium": "Ink and cut-and-pasted painted pages on paper",
  "Dimensions": "19 1/8 x 66 1/2\" (48.6 x 168.9 cm)",
  "CreditLine": "Fractional and promised gift of Jo Carole and Ronald S. Lauder",
  "AccessionNumber": "885.1996",
  "Classification": "Architecture",
  "Department": "Architecture & Design",
  "DateAcquired": "1996-04-09",
  "Cataloged": "Y",
  "ObjectID": 2,
  "URL": "http://www.moma.org/collection/works/2",
  "ThumbnailURL": "http://www.moma.org/media/W1siZiIsIjU5NDA1Il0sWyJwIiwiY29udmVydCIsIi1yZXNpemUgMzAweDMwMFx1MDAzZSJdXQ.jpg?sha=137b8455b1ec6167",
  "Height (cm)": 48.6,
  "Width (cm)": 168.9
}

I want to include a reference to the Artist object via the statement's refs array:

• is this done via Artist WKI
• does it reference an object in another namespace explicitly (e.g. museums.moma.artwork and museums.moma.artist)?
• what if the reference is to a statement/object on a remote peer?

Other, probably not solved via refs:

• what if an object in museums.moma.artist (museum 1) represents the same person/entity in museums.tate.artist (museum 2) (example)?
  • how can one mark them as the same thing
  • can i then query both museums for artworks if i know the WKI of an artist from one of them
• related artworks: Weeping Woman Tate, Weeping Woman Moma 1, Weeping Woman Moma 2

[vyzo]

Two mechanisms supported at the lowest level:

• Multiple refs by wki can be attached to the same object in the statement body.
• Multiple objects can be referred to by the object itself, using the new deps field in the statement body.

[parkan]

@denisnazarov the case you're describing goes like this:

• artist IDs get pulled out and converted into WKIs prefixed by that namespace, if known
• these WKIs are added to the deps field
• namespace-specific merge statement can be made equating two WKIs

Let me give you a simple example of merging based on ukiyo-e. For example, this image:

http://www.mfa.org/collections/object/226444

gets a WKI of mfa:226444, while this one:

http://collections.artsmia.org/art/2006/kirifuri-waterfall-at-mount-kurokami-in-shimotsuke-province-katsushika-hokusai

gets mia:2006. For simplicity, let's say that the prefixes and namespaces are the same. Then in the ukiyoe namespace, you have a statement w/o a body but with wki refs of mfa:226444, mia:2006, which says that from this perspective, these items constitute a single entity. Does that make sense?

[denisnazarov]

Yep makes total sense. I think the artist example is more exciting because it would let you find artworks in a different collection (picassos in tate) using an artist id in yours (picasso in moma).

Is this something we can illustrate with a query with what we have built today? If so would be great to get an example so I can include that in the tutorial/vid.

[parkan]

@denisnazarov yeah, I used this example for clarity, the artist case is equivalent. This kind of join is not supported yet, tho