In my last blog entry I discussed various ways that different RDF datasets assign human-readable labels to resources, with the rdfs:label
property being at the center of them all. I mentioned how schema.org doesn’t use rdfs:label
but its own equivalent of that, schema:name
, which its schema declares as a subproperty of rdfs:label
. Since I wrote that, Fan Li pointed out that Facebook’s Open Graph protocol also has their own equivalent: og:title
, which you can see used in the HTML…
First, reviewing some basics before I discuss the edge cases: resources in RDF are represented by URIs, and the spelling of a given URI often provides no clues about what the URI represents. For example, you wouldn’t know from looking at http://www.wikidata.org/entity/Q144
that it represents “dog” as a Wikipedia topic. (We’ll see below that this is a for a good reason.)
SPARQL 1.1 has been with us for about ten years. Work on SPARQL 1.2 is currently underway, and one nice set of improvements will let us do much more with date and time values.
I’ve had a decent understand of what the VALUES
keyword can do for a while (see SPARQL 1.1’s new VALUES keyword and “Creating Tables of Values in your Queries” in my book Learning SPARQL) but lately I’ve gained a greater appreciation of ways to use it. For example, last month I used it to map codes assigned by an entity recognition tool to schema.org classes. This month I found a nice way to use it to control one of Wikidata’s many cool data visualization…
I recently announced that I have joined Ontotext as a full-time Senior Tech Writer. I have admired their free GraphDB triplestore for a long time (for example, I wrote about how well it supports the GeoSPARQL geospatial extension in October of 2020) and I am now learning about all the great capabilities of their commercial products, such as the scalability of GraphDB Enterprise.
I was catching up with my old friend Paul Prescod the other day. We have not only known each other since the early days of XML, but actually before that: “since XML was a four-letter word”, to quote Paul.