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DS Catalog:SPARQL Query Service/example queries: Difference between revisions
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=Prefix Declarations= | =Prefix Declarations= | ||
==Why are they used?== | |||
Prefix declarations made at the beginning of a SPARQL query tell you which namespaces (ontologies, data models, or other specifications) will be used by the query to construct its triples. Rather than having to write out a long URI every time an entity is referenced, by declaring prefixes, you can shorthand the URIs used later in the query. | |||
For instance, instead of having to type out | |||
<br><br> | |||
<https://catalog.digital-scriptorium.org/entity/Q88> <https://catalog.digital-scriptorium.org/prop/direct/P16> <https://catalog.digital-scriptorium.org/entity/Q13> . | |||
<br><br> | |||
after declaring prefixes, you can type out | |||
<br><br> | |||
wd:Q88 wdt:P16 wd:Q13 . | |||
<br><br> | |||
This makes SPARQL queries much more readable and editable by human beings. | |||
==Which prefix declarations will I need to use the DS Wikibase?== | |||
The following prefix declarations should be at the beginning of any SPARQL query made at [https://catalog.digital-scriptorium.org/query/ the DS Wikibase Query Service endpoint]. | |||
=Basic Example Queries= | =Basic Example Queries= | ||