Een voorbeeld van een optional query.

Similar to this construct query, but showing the flexibility of returning some results that are deeper in the graph.

This is the flexibility, and therefore predictability, that construct query provide. This makes them a good replacement for the less predictable describe queries.

This construct query is similar to this describe query, but has predictable results.

Aggregate functions can be nested, e.g., to calculate the maximum count.

Purpose

For grouping it is necessary to include the grouped by variables in the projection. If such a variable is not wanted in the outer projection, this can be solved with a sub-select. The only purpose of the outer select is to curate the variables that are supposed to be returned.

Use {{variable}} notation in order to include string representations of bindings into HTML strings. This allows human-readable HTML content to be generated from within a SPARQL query. (This is a Triple-specific feature.)

Notice that the HTML string is itself semantically described as a literal with datatype IRI rdf:HTML.

You can press the "Gallery" result set view in order to display a gallery view of the returned HTML widgets. The gallery widget requires that the HTML strings are bound to variable ?widget.

Binding a variable

The bind keyword allows variables to be introduced that do not appear in a graph pattern.