SPARQL Query Azure Function

This Azure Function allows you to execute a SPARQL query over one or more RDF sources.

Function Endpoints

• POST /api/FedQuery: Execute a SPARQL query with specified RDF sources.

How to Use

You can use CURL, Postman, or make a POST request programmatically to call this function.

1. Using curl

curl -X POST "/api/FedQuery" \
     -H "Content-Type: application/json" \
     -d '{
           "sparql": "SELECT * WHERE { ?s ?p ?o } ",
           "sources": [
               "https://lab1cattledata.solidcommunity.net/RDF/CattleData.ttl",
               "https://lab2cattledata.solidcommunity.net/RDF/PoultryRDF.ttl"
           ]
         }'
    

2. Using Postman

• Set the HTTP method to POST.
• Enter the URL for the function endpoint: /api/FedQuery
• Set the headers: Content-Type = application/json
• In the body, select "raw" and enter the JSON query, e.g.:

{
    "sparql": "SELECT * WHERE { ?s ?p ?o }",
    "sources": ["https://lab1cattledata.solidcommunity.net/RDF/CattleData.ttl", "https://lab2cattledata.solidcommunity.net/RDF/PoultryRDF.ttl"]
}
    

3. Programmatically

Node.js Example

const fetch = require('node-fetch');

const query = {
    sparql: "SELECT * WHERE { ?s ?p ?o }",
    sources: [
        "https://lab1cattledata.solidcommunity.net/RDF/CattleData.ttl",
        "https://lab2cattledata.solidcommunity.net/RDF/PoultryRDF.ttl"
    ]
};

fetch('/api/FedQuery', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json'
    },
    body: JSON.stringify(query)
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
    

Python Example

import requests
import json

url = "/api/FedQuery"
query = {
    "sparql": "SELECT * WHERE { ?s ?p ?o }",
    "sources": [
        "https://lab1cattledata.solidcommunity.net/RDF/CattleData.ttl",
        "https://lab2cattledata.solidcommunity.net/RDF/PoultryRDF.ttl"
    ]
}

headers = {'Content-Type': 'application/json'}

response = requests.post(url, json=query, headers=headers)
print(response.json())
    

Request Body

The POST request requires a JSON body with the following structure:

{
    "sparql": "SELECT * WHERE { ?s ?p ?o }",
    "sources": ["https://lab1cattledata.solidcommunity.net/RDF/CattleData.ttl", "https://lab2cattledata.solidcommunity.net/RDF/PoultryRDF.ttl"]
}
    

Responses

• 200 OK: Query results in JSON format.
• 400 Bad Request: Invalid JSON or missing fields.
• 500 Internal Server Error: An internal error occurred.