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XQuery op:pattern

MarkLogic 12 Product Documentation
op.pattern

op.pattern(
   subjects as Sequence,
   predicates as Sequence,
   objects as Sequence,
   [systemCols as Object[]]
) as patterndef

Summary

This function builds the parameters for the op.fromTriples function. The result is passed to op.fromTriples to project rows from the graph of triples. The columns in a pattern become the columns of the row. The literals in a pattern are used to match triples. You should specify at least one literal in each pattern, usually the predicate. Where a column appears in more than one pattern, the matched triples are joined to form the row. You can specify optional triples with a prototype.joinLeftOuter with a separate op.fromTriples .

Parameters
subjects One column or one or more literal values, such as the literal returned by a sem.iri call. The column can be named with a column function such as op.col, op.viewCol, or op.schemaCol.
predicates One column or one or more literal values, such as the literal returned by a sem.iri call. The column can be named with a column function such as op.col, op.viewCol, or op.schemaCol.
objects One column or one or more literal values, such as the literal returned by a sem.iri call. The column can be named with a column function such as op.col, op.viewCol, or op.schemaCol.
systemCols Specifies the result of an op.fragmentIdCol or op.graphCol function to add columns for the fragment id or graph iri.

Example

const op = require('/MarkLogic/optic');
// prefixer is a factory for sem:iri() constructors in a namespace
const resource   = op.prefixer('http://dbpedia.org/resource/');
const foaf   = op.prefixer('http://xmlns.com/foaf/0.1/');
const onto = op.prefixer('http://dbpedia.org/ontology/');

const person = op.col('person');

const Plan =
    op.fromTriples([
        op.pattern(person, onto('birthPlace'), resource('Brooklyn')),
        op.pattern(person, foaf("name"), op.col("name"), op.graphCol('graph-id'))
    ])
    .select();
Plan.result();

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