Generates a SPARQL OPTIONAL group pattern.
OPTIONAL
Empty clauses are dropped; when none survives, the result is the empty fragment.
The graph pattern clauses
The SPARQL OPTIONAL group pattern, or the empty fragment for no clauses
SPARQL 1.1 Optional Patterns
Generates a SPARQL
OPTIONALgroup pattern.Empty clauses are dropped; when none survives, the result is the empty fragment.