verifiedPillar 4 — Validation (SHACL Core)

pgrdf.validate(data_graph_id BIGINT, shapes_graph_id BIGINT, mode TEXT DEFAULT 'native') → JSONB validates the data graph against the shapes graph and returns a W3C sh:ValidationReport-shape JSONB document.

The default mode => 'native' is W3C SHACL Core — the full SHACL Core constraint set, conformant against the W3C SHACL Core test suite at 25/25. Backed by the shacl crate (0.3.2) from the rudof project. The mode argument also exposes 'pgrdf' — the shipped, authoritative SHACL-SPARQL gate, the pgRDF-native handler that evaluates sh:sparql / sh:select / sh:ask custom constraints directly against the hexastore and returns the correct W3C verdict. The alternate 'sparql' (rudof SparqlEngine) reaches the engine but carries an open correctness caveat (E-014). See SHACL-SPARQL.

Topics in this pillar

• info Mental model.
• description Worked example — minCount, datatype, nodeKind constraints.
• verified SHACL Core components — what's supported.
• fact_check Report as data — querying violations with regular SQL.
• verified SHACL-SPARQL — the shipped mode => 'pgrdf' custom-constraint gate (pgRDF-native, authoritative, direct hexastore evaluation); the alternate 'sparql' (rudof SparqlEngine) reaches the engine but is E-014-buggy.

At a glance

SELECT pgrdf.validate(1, 2);
--  → { "conforms": false, "results": [ {...}, {...} ] }

Next — Mental model →

auto_storiesTraining

Validation is the simplest of the four pillars conceptually — one UDF, one report — but the SHACL Core surface is broad. Take the pages in order:

• info Start with the Mental model — what a shapes graph is, what a validation report is, why this matters.
• description Run the Worked example — minCount + datatype + nodeKind constraint composition, end-to-end in psql.
• verified Read the SHACL Core components reference — what's supported and what's not. Bookmark this page.
• fact_check Then Report as data — SHACL reports are JSONB. Querying violations with regular SQL is the gate-ingestion idiom.
• verified Then SHACL-SPARQL — the shipped mode => 'pgrdf' gate for custom constraint components defined as embedded SPARQL, the authoritative pgRDF-native handler evaluating them directly against the hexastore; the alternate 'sparql' (rudof SparqlEngine) reaches the engine but carries the E-014 caveat.

Learn more

• school Shapes Constraint Language (SHACL) — the W3C recommendation.
• school SHACL Playground — paste a data graph + shapes graph, see the report in your browser. Great for prototyping.
• code rudof project's shacl crate — the engine pgRDF wraps for 'native' (SHACL Core) and the alternate 'sparql' mode (E-014-caveated); the authoritative SHACL-SPARQL 'pgrdf' mode is pgRDF-native.
• school Knublauch & Kontokostas, Validating RDF Data — book on SHACL by the spec editors.