This endpoint makes it possible to query the Data Commons knowledge graph using SPARQL. SPARQL is a query language developed to retrieve data from RDF graph content on the web. It leverages the graph structure innate in the data it queries to return specific information.

Note: Data Commons only supports a limited subset of SPARQL functionality at this time: specifically, only the keywords WHERE, ORDER BY, DISTINCT, and LIMIT are supported.

Request

Note: GET requests are not provided because they are inconvenient to use with SPARQL.

POST request

URL: https://api.datacommons.org/v2/sparql Header: X-API-Key: AIzaSyCTI4Xz-UW_G2Q2RfknhcfdAnTHq5X5XuI JSON data: { "query": "SPARQL_QUERY" }

Query parameters

Name	Type	Description
key Required	string	Your API key. See the the section on authentication for instructions on how to get a key.
query Required	string	A SPARQL query string. In the query, all desired entities must be specified; wildcards are not supported. Each node or entity should have a `typeOf` condition, for example, `?ENTITY_NAME typeOf City`.

Response

The response looks like:

{
  "header": [
    STRING
  ],
  "rows": [
    {
      "cells": [
        {
          "value": STRING
        }
      ]
    },
    ...
  ]
}

Response fields

Name	Type	Description
header	list	List of strings corresponding to the query variables.
rows	list	List of `row` objects, with each containing a list of cells and its cell values.
cells	object	Contains string field `value` corresponding to the queried variable.

Examples

Example 1: Query the Data Commons knowledge graph with SPARQL

Retrieve a list of 10 biological specimens (DCID: BiologicalSpecimen) in reverse alphabetical order.

Request:

curl --request POST \
  --url https://api.datacommons.org/v2/sparql \
  --header 'X-API-Key: AIzaSyCTI4Xz-UW_G2Q2RfknhcfdAnTHq5X5XuI' \
  --data '{
            "query": "SELECT ?name \
                WHERE { \
                  ?biologicalSpecimen typeOf BiologicalSpecimen . \
                  ?biologicalSpecimen name ?name
                }
                ORDER BY DESC(?name)
                LIMIT 10"
}'

Response:

{
  "header": ["?name"],
  "rows": [
    {
      "cells": [
        {
          "value": "x Triticosecale"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Silene"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Silene"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Silene"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Pseudelymus saxicola (Scribn. & J.G.Sm.) Barkworth & D.R.Dewey"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Pseudelymus saxicola (Scribn. & J.G.Sm.) Barkworth & D.R.Dewey"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Pseudelymus saxicola (Scribn. & J.G.Sm.) Barkworth & D.R.Dewey"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Pseudelymus saxicola (Scribn. & J.G.Sm.) Barkworth & D.R.Dewey"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Pseudelymus saxicola (Scribn. & J.G.Sm.) Barkworth & D.R.Dewey"
        }
      ]
    },
    {
      "cells": [
        {
          "value": "x Pseudelymus saxicola (Scribn. & J.G.Sm.) Barkworth & D.R.Dewey"
        }
      ]
    }
  ]
}