Advanced Graph Querying: Difference between revisions
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MemCP exposes its tested SPARQL subset at <code>/rdf/<database></code>. Queries can combine triple patterns, FILTER expressions, OPTIONAL blocks, bindings, and supported update forms. Turtle data can be loaded through <code>/rdf/<database>/load_ttl</code>. | MemCP exposes its tested SPARQL subset at <code>/rdf/<database></code>. Queries can combine triple patterns, FILTER expressions, OPTIONAL blocks, bindings, and supported update forms. Turtle data can be loaded through <code>/rdf/<database>/load_ttl</code>. | ||
< | <pre> | ||
SELECT ?person ?name WHERE { | SELECT ?person ?name WHERE { | ||
?person <http://xmlns.com/foaf/0.1/name> ?name . | ?person <http://xmlns.com/foaf/0.1/name> ?name . | ||
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FILTER(!BOUND(?active) || ?active = true) | FILTER(!BOUND(?active) || ?active = true) | ||
} | } | ||
</ | </pre> | ||
Update templates include tested DELETE/INSERT/WHERE forms. RDF literals and IRIs must use the supported escaping rules; application input must not be concatenated into query text without validation. | Update templates include tested DELETE/INSERT/WHERE forms. RDF literals and IRIs must use the supported escaping rules; application input must not be concatenated into query text without validation. | ||
Latest revision as of 12:13, 28 August 2026
Advanced Graph Querying
MemCP exposes its tested SPARQL subset at /rdf/<database>. Queries can combine triple patterns, FILTER expressions, OPTIONAL blocks, bindings, and supported update forms. Turtle data can be loaded through /rdf/<database>/load_ttl.
SELECT ?person ?name WHERE {
?person <http://xmlns.com/foaf/0.1/name> ?name .
OPTIONAL { ?person <http://example.org/active> ?active . }
FILTER(!BOUND(?active) || ?active = true)
}
Update templates include tested DELETE/INSERT/WHERE forms. RDF literals and IRIs must use the supported escaping rules; application input must not be concatenated into query text without validation.
This page documents a tested subset, not complete SPARQL standard conformance or a separate general-purpose graph execution engine. Add successful and must-fail integration tests before advertising another construct. See Introduction to RDF and SQL over REST.
Property-path roadmap
SPARQL property paths remain a planned extension. The intended progression covers one-step alternatives/sequences, inverse paths, optional paths and transitive */+ traversal. Recursive traversal needs explicit visited-set semantics, cancellation, bounds and a physical representation that does not repeatedly materialize the same nodes. Until tests and documentation say otherwise, do not assume property-path syntax is accepted.