.. _datasets:

=======================
Datasets in JudaicaLink
=======================

JudaicaLink provides structured datasets that integrate Jewish studies sources into a Linked Open Data (LOD) knowledge graph. These datasets are accessible via SPARQL queries, downloadable RDF dumps, and through the JudaicaLink API.

Available Datasets
==================
The following datasets are included in JudaicaLink:

1. YIVO Encyclopedia
--------------------

* Description: Biographical and historical entries from the YIVO Institute for Jewish Research.
* Entities: Persons, places, and organizations.
* Data Access:

  * SPARQL: Query at `https://data.judaicalink.org/sparql.html <https://data.judaicalink.org/sparql.html>`_
  * Entity Pages: `https://data.judaicalink.org/data/html/yivo/ <https://data.judaicalink.org/data/html/yivo/>`_

2. Stolpersteine in Mainz
-------------------------

* Description: Data on commemorative stones dedicated to Holocaust victims.
* Entities: Persons and memorial sites.
* Data Access:

  * SPARQL: Query dataset under `stolpersteine`
  * Entity Pages: `https://data.judaicalink.org/data/html/stolpersteine/ <https://data.judaicalink.org/data/html/stolpersteine/>`_

3. Biographisches Handbuch der Rabbiner
---------------------------------------

* Description: Biographical records of Jewish rabbis from various historical periods.
* Entities: Persons, institutions, and related documents.
* Data Access:

  * RDF: `https://data.judaicalink.org/dumps/rabbiner.rdf`
  * SPARQL queries available for detailed searches.

4. Footprints - Jewish Books through Time and Place
---------------------------------------------------

* Description: A dataset tracing the movement of Jewish books across different regions and owners.
* Entities: Books, authors, owners, locations.
* Data Access:

  * SPARQL: Query at `footprints` dataset.
  * JSON-LD Access: `https://data.judaicalink.org/data/jsonld/footprints/`

5. Compact Memory (CM) Indexed Entities
---------------------------------------

* Description: Extracted named entities (persons, locations, topics) from historical Jewish periodicals.
* Entities: Persons, places, organizations, topics.
* Data Access:
    * SPARQL Query Example:

    .. code-block:: sparql
        :linenos:

        SELECT ?entity ?label WHERE {
          ?entity a jl:Person ;
                  rdfs:label ?label .
        } LIMIT 10

    * Content Negotiation: Available in RDF/XML, JSON-LD, and Turtle.


Using the Datasets
==================

1. Querying Data with SPARQL
----------------------------

Users can run SPARQL queries against the JudaicaLink **SPARQL Endpoint**:

* **Endpoint URL** : `https://data.judaicalink.org/sparql.html <https://data.judaicalink.org/sparql.html>`_
* **Example Query**  (Retrieve all persons in the dataset):

.. code-block:: sparql
    :linenos:

    SELECT ?person ?name WHERE {
    ?person a jl:Person ;
            rdfs:label ?name .
    } LIMIT 100

2. Downloading RDF Dumps
------------------------

Users can download full dataset RDF dumps for offline use:

* **Download URL**: `https://data.judaicalink.org/dumps/ <https://data.judaicalink.org/dumps/>`_
* **Example:**  Download `yivo.rdf`

::

  wget https://data.judaicalink.org/dumps/yivo.rdf


3. Accessing Data via Content Negotiation
-----------------------------------------

JudaicaLink supports content negotiation, allowing users to request data in different formats.

* **Formats available:** HTML, JSON-LD, RDF/XML, Turtle.
* **Example Requests:**

    * JSON-LD: `https://data.judaicalink.org/data/jsonld/yivo/moses-mendelssohn`
    * RDF/XML: `https://data.judaicalink.org/data/xml/yivo/moses-mendelssohn`

4. Using the JudaicaLink API
----------------------------

For automated access and data retrieval:

* **Base API URL** : `https://data.judaicalink.org/api/`
* **Example API Query (Get data for an entity):**

::

    curl -H "Accept: application/json" https://data.judaicalink.org/data/jsonld/yivo/moses-mendelssohn

Next Steps
==========

* Learn how to refine your **SPARQL queries** in the :ref:`SPARQL Guide <advanced_topics_sparql_guide>`.
* Explore the **Entity Pages** to browse individual datasets.
* If you need help, check the :ref:`FAQs <faq>` or contact us at `https://labs.judaicalink.org/contact/ <https://labs.judaicalink.org/contact/>`_.