{"id":1790,"date":"2021-01-28T21:04:21","date_gmt":"2021-01-28T21:04:21","guid":{"rendered":"https:\/\/jan.schnasse.org\/blog\/?p=1790"},"modified":"2026-09-28T11:38:03","modified_gmt":"2026-09-28T09:38:03","slug":"datamodelling-with-a-json-to-rdf-approach","status":"publish","type":"post","link":"https:\/\/jan.schnasse.org\/blog\/2021\/01\/28\/datamodelling-with-a-json-to-rdf-approach\/","title":{"rendered":"Datamodelling with a „Json to Rdf“ Approach."},"content":{"rendered":"
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\n

At the example of this stackoverflow question:<\/p>\n

„Supposing we have the following triple in Turtle syntax:<\/p>\n

<http:\/example.com\/Paul> <http:\/example.com\/running> <http:\/example.com\/10miles> .\n<\/code><\/pre>\n
How do I add a start and end time? For example if I want to say he started at 10 am and finished his 10miles run at 12 am. I want to use xsd:dateTime<\/code>.“<\/p>\n
https:\/\/stackoverflow.com\/questions\/49726990<\/a><\/p>\n<\/div>\n<\/div>\n
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Sometimes it can be hard to create good, well fitting models. In my own experience it is crucial to identify a well defined set of entities and relations to create a vocabulary from.\u00a0 Some people prefer to use visual strategies to develop their models. I prefer to write models in structured text.\u00a0 This has the advantage that the process of modeling directly leads into actual coding.<\/p>\n
Here is an example on how I would tackle the question<\/a> .<\/p>\n
\n
1. The modelling part (not much RDF involved)<\/strong><\/p>\n
{\n    \"runs\"<\/span>: [\n        {\n            \"id\"<\/span>: \"runs:0000001\"<\/span>,\n            \"distance\"<\/span>: {\n                \"length\"<\/span>: 10.0<\/span>,\n                \"unit\"<\/span>: \"mile\"<\/span>\n            },\n            \"time\"<\/span>: {\n                \"start\"<\/span>: \"2018-04-09T10:00:00\"<\/span>,\n                \"end\"<\/span>: \"2018-04-09T12:00:00\"<\/span>\n            },\n            \"runner\"<\/span>: {\n                \"id\"<\/span>: \"runner:0000002\"<\/span>,\n                \"name\"<\/span>: \"Paul\"<\/span>\n            }\n        }\n    ]\n}\n<\/code><\/pre>\n
oi run.json -t context<\/code><\/pre>\n
The resulting context is just a stub. But with a few additions we can easily create a context document to define id’s and types for each vocable\/entity\/relation.<\/p>\n
2. The RDF part: define a proper context for your document.<\/strong><\/p>\n
   {\n    \"@context\"<\/span>: {\n        \"ical\"<\/span>: \"http:\/\/www.w3.org\/2002\/12\/cal\/ical#\"<\/span>,\n        \"xsd\"<\/span>: \"http:\/\/www.w3.org\/2001\/XMLSchema#\"<\/span>,\n        \"runs\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/runs\/\"<\/span>,\n            \"@container\"<\/span>: \"@list\"<\/span>\n        },\n        \"distance\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/distance\"<\/span>\n        },\n        \"length\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/length\"<\/span>,\n            \"@type\"<\/span>: \"xsd:double\"<\/span>\n        },\n        \"unit\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/unit\"<\/span>\n        },\n        \"runner\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/runner\/\"<\/span>\n        },\n        \"name\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/name\"<\/span>\n        },\n        \"time\"<\/span>: {\n            \"@id\"<\/span>: \"info:stack\/49726990\/time\"<\/span>\n        },\n        \"start\"<\/span>: {\n            \"@id\"<\/span>:\"ical:dtstart\"<\/span>,\n            \"@type\"<\/span>: \"xsd:dateTime\"<\/span>\n        },\n        \"end\"<\/span>: {\n            \"@id\"<\/span>:\"ical:dtend\"<\/span>,\n            \"@type\"<\/span>: \"xsd:dateTime\"<\/span>\n        },\n        \"id\"<\/span>: \"@id\"<\/span>\n    }\n}<\/code><\/pre>\n
3. The fun part: Throw it to an RDF converter of your choice<\/strong><\/p>\n
Or simply use ‚oi‘:<\/p>\n
 \noi run.json -f run.context -t ntriples\n<\/code><\/pre>\n
Prints:<\/p>\n
 \n_:b0 <info:stack\/49726990\/runs\/> _:b3 .\n_:b3 <http:\/\/www.w3.org\/1999\/02\/22-rdf-syntax-ns#first> <info:stack\/49726990\/runs\/0000001> .\n_:b3 <http:\/\/www.w3.org\/1999\/02\/22-rdf-syntax-ns#rest> <http:\/\/www.w3.org\/1999\/02\/22-rdf-syntax-ns#nil> .\n<info:stack\/49726990\/runs\/0000001> <info:stack\/49726990\/distance> _:b1 .\n<info:stack\/49726990\/runs\/0000001> <info:stack\/49726990\/runner\/> <info:stack\/49726990\/runner\/0000002> .\n<info:stack\/49726990\/runs\/0000001> <info:stack\/49726990\/time> _:b2 .\n_:b1 <info:stack\/49726990\/length> \"1.0E1\"^^<http:\/\/www.w3.org\/2001\/XMLSchema#double> .\n_:b1 <info:stack\/49726990\/unit> \"mile\" .\n<info:stack\/49726990\/runner\/0000002> <info:stack\/49726990\/name> \"Paul\" .\n_:b2 <http:\/\/www.w3.org\/2002\/12\/cal\/ical#dtend> \"2018-04-09T12:00:00\"^^<http:\/\/www.w3.org\/2001\/XMLSchema#dateTime> .\n_:b2 <http:\/\/www.w3.org\/2002\/12\/cal\/ical#dtstart> \"2018-04-09T10:00:00\"^^<http:\/\/www.w3.org\/2001\/XMLSchema#dateTime> .\n<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
At the example of this stackoverflow question: „Supposing we have the following triple in Turtle syntax: <http:\/example.com\/Paul> <http:\/example.com\/running> <http:\/example.com\/10miles> . How do I add a start and end time? For example if I want to say he started at 10 am and finished his 10miles run at 12 am. I want to use xsd:dateTime.“ https:\/\/stackoverflow.com\/questions\/49726990 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,9],"tags":[],"class_list":["post-1790","post","type-post","status-publish","format-standard","hentry","category-development","category-java"],"_links":{"self":[{"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/posts\/1790","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/comments?post=1790"}],"version-history":[{"count":1,"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/posts\/1790\/revisions"}],"predecessor-version":[{"id":4009,"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/posts\/1790\/revisions\/4009"}],"wp:attachment":[{"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/media?parent=1790"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/categories?post=1790"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jan.schnasse.org\/blog\/wp-json\/wp\/v2\/tags?post=1790"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
This is how it looks in JSON-Playground<\/a><\/p>\n
We store the json document in a file run.json<\/strong>. From here we can use the ‚oi‘ command line tool<\/a> , to create an adhoc context.<\/p>\n