JSON SPARQL Query results contain incorrect datatype entries

[bnouwt]

Hi,

the SPARQL results (see below) are unfortunately not accepted by LodView due to the datatype: "null" in entries with type: "uri". According to the JSON SPARQL results this datatype field is only allowed with type: "typed-literal".

These rogue datatype entries are caused by pydantic and the data models that are being defined in app.py.

For testing purposes I've disabled the pydantic transformation by returning a dict instead of SPARQLEndpointResult and this indeed returns the correct JSON. So, the result from the handle_query(...) method is correct, but is malformed by pydantic 👍

Regards, Barry

{
  "head": {
    "vars": [
      "s",
      "p",
      "o"
    ]
  },
  "results": {
    "bindings": [
      {
        "p": {
          "type": "uri",
          "value": "http://example.org/mainPersonsInvolved",
          "datatype": null
        },
        "o": {
          "type": "uri",
          "value": "https://tno.nl/Neil_Armstrong",
          "datatype": null
        }
      },
      {
        "p": {
          "type": "uri",
          "value": "http://example.org/hasOccurredAt",
          "datatype": null
        },
        "o": {
          "type": "literal",
          "value": "1969-07-20T20:05:00+00:00",
          "datatype": "http://www.w3.org/2001/XMLSchema#dateTime"
        }
      },
      {
        "p": {
          "type": "uri",
          "value": "http://example.org/hasNumberOfPeople",
          "datatype": null
        },
        "o": {
          "type": "literal",
          "value": "500",
          "datatype": "http://www.w3.org/2001/XMLSchema#integer"
        }
      }
    ]
  }
}