411 REFERENCE · Wikibooks
SPARQL/Variables
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
A query variable is marked by the use of either "?" or "$"; the "?" or "$" is not part of the variable name. In a query, $abc and ?abc identify the same variable.
In this book only variables marked with "?" are used.
Allowable characters are [a-z], [A-Z], [0-9], _, · and also diacrictics like áéíóú etcetera.
Example
SELECT $child_of_Bach $child_of_BachLabel
WHERE
{
$child_of_Bach wdt:P22 wd:Q1339.
SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}