Querying

While some of the property definition in the example may have felt a bit verbose (we’ll get into more patterns later to help manage the redundancy), but it starts to pay off by the expressiveness from being able to query all the information in your workspace.

First, let’s update the workspace config file to tell Knowboard we want to enable the SPARQL server:

.knowboard.toml

# ...
exclude = [".git/**"]

[sparql_server]
listen = "auto" # or specific port like "17878"

Note

The value “auto” tells Knowboard to pick an arbitrary available port at startup. This is helpful in avoiding port conflicts, but also means the port will change each time you restart Knowboard. You can provide a specific port number as well, but this will need to be unique for each of your workspaces.

Knowboard provides a simple web-based SPARQL UI.

In VSCode the UI can be opened using the Command Pallete:

Cmd+Shift+P (Mac)
Ctrl+Shift+P (Windows)

> Knowboard: Open SPARQL UI

Knowboard also provides a Code Lens in the .knowboard.toml config to open a browser to the UI:

Or if you have a specific port defined, you can navigate directly to it in the browser, such as http://localhost:17878.

Knowboard can also be used with a variety of standard SPARQL clients

Testing a query

In SPARQL the basic “show me everything” query looks like this:

SELECT * WHERE { ?subject ?predicate ?object } LIMIT 3

This should return a selection of the information we’ve defined in the workspace like:

subject	predicate	object
tag:me@example.com,2026:my-workspace/authors/jane-austen	http://schema.org/name	Jane Austen
tag:me@example.com,2026:my-workspace/authors/jane-austen	http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://schema.org/Person
tag:me@example.com,2026:my-workspace/authors/f-scott-fitzgerald	http://schema.org/name	F. Scott Fitzgerald

Structuring the results

To get something more insightful, SPARQL enables us to query the structure and connections between different items, such as associating book titles with the author’s name:

query.rq

PREFIX schema: <http://schema.org/>

SELECT ?bookName ?authorName WHERE {
  ?book a schema:Book ;
        schema:name ?bookName ;
        schema:author ?author .
  ?author schema:name ?authorName .
}

bookName	authorName
The Great Gatsby	F. Scott Fitzgerald
Pride and Prejudice	Jane Austen

See the references for additional SPARQL resources.