https://github.com/linkml/linkml-sparql

Maps LinkML queries to SPARQL and back (ALPHA)
https://github.com/linkml/linkml-sparql

linked-data linkml ontology orm queries rdf rdflib semantic-web sparql

Last synced: 26 days ago
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Maps LinkML queries to SPARQL and back (ALPHA)

• Host: GitHub
• URL: https://github.com/linkml/linkml-sparql
• Owner: linkml
• Created: 2021-07-20T02:30:58.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2021-07-20T02:31:10.000Z (over 3 years ago)
• Last Synced: 2024-11-10T10:13:57.097Z (3 months ago)
• Topics: linked-data, linkml, ontology, orm, queries, rdf, rdflib, semantic-web, sparql
• Language: Python
• Homepage:
• Size: 10.7 KB
• Stars: 3
• Watchers: 4
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# linkml-sparql: ORM for SPARQL endpoints

This provides a way of querying either in-memory RDF graphs or remote SPARQL endpoints using a LinkML specified datamodel.

## Step 1: Define your datamodel and RDF bindings

As an example, a small schema for a portion of DBpedia:

```yaml

id: http://dbpedia.org/ontology/

imports:

 - linkml:types

prefixes:

  dbont: http://dbpedia.org/ontology/

  dbproperty: http://dbpedia.org/property/

  dbr: http://dbpedia.org/resource/

  linkml: https://w3id.org/linkml/

  geo: http://www.w3.org/2003/01/geo/wgs84_pos#

  wd: http://www.wikidata.org/entity/

  rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns#

  rdfs: http://www.w3.org/2000/01/rdf-schema#

  

default_prefix: dbont

classes:

  Thing:

    slots:

      - id

      - label

      - comment

      - type

  Food:

    is_a: Thing

    exact_mappings:

      - wd:Q2095

    slots:

      - servingTemperature

      - servingSize

      - alias

      - cuisine

      - ingredientName

      - origin

      - region

      - distributor

      - approximateCalories

      - carbohydrate

      - fat

      - protein

```

## Step 2: Create Python dataclasses

```bash

pipenv run gen-python dbont.yaml > dbont.py

```

## Step 3: Code

```python

from dbont import Food

from linkml_sparql import QueryEngine, SparqlEndpoint

   schema = YAMLGenerator(SCHEMA).schema

   qe = QueryEngine(schema=schema,

                         endpoint=SparqlEndpoint(url='http://dbpedia.org/sparql/'),

                         lang='en')

   objs = qe.query(type=Food.class_class_curie,

                        origin='dbr:Scotland',

                        target_class=Food)

   for obj in objs:

       print(f'{obj.id} {obj.label} distributed by {obj.distributor}')

```

## More documentation

More documentation coming soon. For now, consult the tests.

## TODOs

Functionality is very incomplete

 - remote querying via DESCRIBE can be inefficient

 - ...lots more