Aggregates + GROUP BY

COUNT, SUM, AVG, MIN, MAX, GROUP_CONCAT, SAMPLE — all standard SPARQL 1.1 aggregates. MIN / MAX are type-aware.

What it does

All seven SPARQL 1.1 aggregate functions translate to SQL aggregates over the dynamically-translated query. MIN and MAX are type-aware — they pick numeric ordering over numeric literals and lexical ordering over strings, so you don't get the SPARQL-foot-gun where "10"^^xsd:integer < "9"^^xsd:integer because of string comparison.

Function	SQL equivalent	Notes
`COUNT(?v)`	`count(...)`	DISTINCT supported.
`SUM(?v)`	`sum(...)`	Numeric typed literals.
`AVG(?v)`	`avg(...)`	Returns `xsd:decimal`.
`MIN(?v)` / `MAX(?v)`	per-type ordering	Numeric vs. lexical chosen by the executor.
`GROUP_CONCAT(?v; SEPARATOR=",")`	`string_agg(...)`	Custom separator.
`SAMPLE(?v)`	arbitrary first row	One value per group.

Why you'd use it

Project managers — graph-shape reports in one query: counts per predicate, sums per category, distinct value samples.
Data scientists — bread-and-butter analytical queries inside SPARQL, no client-side post-process.

Example

sql

-- Triple count per predicate.
SELECT * FROM pgrdf.sparql(
  'SELECT ?p (COUNT(?o) AS ?n)
     WHERE { ?s ?p ?o }
   GROUP BY ?p
   ORDER BY DESC(?n)');
--  → {"p": "http://xmlns.com/foaf/0.1/name", "n": "4"}

COUNT(?o) and ?o is a variable — pgRDF counts non-null bindings. Use COUNT(*) for an unconditional count.

Aggregates + GROUP BY ​

What it does ​

Why you'd use it ​

Example ​

Tests ​

Aggregates + GROUP BY

What it does

Why you'd use it

Example

Tests