Class: SPARQL::Algebra::Operator::Update

Inherits:
Operator
  • Object
show all
Includes:
Update
Defined in:
lib/sparql/algebra/operator/update.rb

Overview

The SPARQL GraphPattern prefix operator.

[29] Update ::= Prologue ( Update1 ( ';' Update )? )?

Examples:

SPARQL Grammar

PREFIX     : <http://example.org/> 
PREFIX foaf: <http://xmlns.com/foaf/0.1/> 
DELETE  { ?a foaf:knows ?b }
INSERT { ?b foaf:knows ?a }
WHERE { ?a foaf:knows ?b }

SSE

(prefix ((: <http://example.org/>)
         (foaf: <http://xmlns.com/foaf/0.1/>))
 (update
  (modify
   (bgp (triple ?a foaf:knows ?b))
   (delete ((triple ?a foaf:knows ?b)))
   (insert ((triple ?b foaf:knows ?a)))) ))

SPARQL Grammar (update multiple)

PREFIX     : <http://example.org/> 
PREFIX foaf: <http://xmlns.com/foaf/0.1/> 

DELETE { ?a foaf:knows ?b . }
WHERE { ?a foaf:knows ?b . }
;
INSERT { ?b foaf:knows ?a . }
WHERE { ?a foaf:knows ?b .}

SSE (update multiple)

(prefix ((: <http://example.org/>)
         (foaf: <http://xmlns.com/foaf/0.1/>))
 (update
  (modify
   (bgp (triple ?a foaf:knows ?b))
   (delete ((triple ?a foaf:knows ?b))))
  (modify
   (bgp (triple ?a foaf:knows ?b))
   (insert ((triple ?b foaf:knows ?a))))))

See Also:

Constant Summary collapse

NAME = 
[:update]

Instance Method Summary collapse

Methods included from Update

#empty?, #graph_name=, #unshift, #variables

Instance Method Details

#execute(queryable, **options) ⇒ RDF::Queryable

Executes this upate on the given queryable graph or repository.

Parameters:

  • queryable (RDF::Queryable) —

    the graph or repository to write

  • options (Hash{Symbol => Object}) —

    any additional keyword options

Options Hash (**options):

  • debug (Boolean) —

    Query execution debugging

Returns:

Raises:

  • (NotImplementedError) —

    If an attempt is made to perform an unsupported operation

  • (IOError) —

    If queryable is immutable

See Also:



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# File 'lib/sparql/algebra/operator/update.rb', line 67

def execute(queryable, **options)
  debug(options) {"Update"}
  raise IOError, "queryable is not mutable" unless queryable.mutable?
  operands.each do |op|
    op.execute(queryable, **options.merge(depth: options[:depth].to_i + 1))
  end
  queryable
end

#to_sparql(**options) ⇒ String

Returns a partial SPARQL grammar for this operator.

Returns:

  • (String) 


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# File 'lib/sparql/algebra/operator/update.rb', line 81

def to_sparql(**options)
  str = operands.map { |e| e.to_sparql(**options) }.join(";\n")
end