Get Catalog Query¤

This task looks a query up in a query catalog and emits one entity describing it, without running it.

The entity carries the catalog graph, the query IRI, its label and description, its type, its query text as stored, and the names of the placeholders that text contains. The query text is emitted unfilled, with its placeholders intact, which is what makes it useful to a task that wants to inspect or transform a query rather than execute one.

With a query chosen on the task, it emits exactly one entity and takes no input. With the query left empty, the queries to look up arrive on an input port instead, as a catalog graph and a query IRI per entity, and one entity is emitted for each. An incoming entity that leaves the catalog graph empty falls back to the catalog chosen on the task, so a list of query IRIs from one catalog needs no constant column.

It emits exactly what List Catalog Queries emits, in the same order, and the first two values it emits are what it accepts on its own input port - so the two tasks chain directly. Execute Catalog Query is the one that runs a query.

A query IRI that the named catalog does not hold fails the task rather than being skipped, because a workflow asking for a specific query and silently receiving nothing is the harder failure to notice.

Parameter¤

Catalog Graph¤

The graph the query is read from. The list offers the query catalogs first, then the shape catalogs, then any other graph that holds queries, with the number of read and write queries each one contains.

• ID: catalog_graph
• Datatype: string
• Default Value: None

Query Kind¤

Which half of the catalog the query list offers.

• ID: query_kind
• Datatype: string
• Default Value: all

Query¤

The query to use, picked by its label. Choose the catalog graph and the query kind first; changing either of them clears this field.

• ID: query
• Datatype: string
• Default Value: None

Advanced Parameter¤

None

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