Export Quads

Export Quads #

Problems #

How can I export my database to files, using standard representational format?

Solution #

This code creates a set of quads, then exports them into several formats:

See the full list of source code 
package main

import (
	"fmt"
	"github.com/cayleygraph/quad"
	"reflect"

	// Add some predefined vocabularies
	"github.com/cayleygraph/quad/voc/rdf"
	"github.com/tombenke/cayley-cookbook-src/kbase/voc/foaf"
)

func main() {

	// Create Quads about some people using Blank Nodes as references
	quadsWithBNodes := makeQuadsWithBNodes()

	// Take a look at the resulted quads
	printQuads(quadsWithBNodes)

	// Create Quads about some people using IRIs as references
	quadsWithIRIs := makeQuadsWithIRIs()

	// Take a look at the resulted quads
	printQuads(quadsWithIRIs)
}

func makeQuadsWithBNodes() []quad.Quad {
	label := "people"
	quads := []quad.Quad{}

	// Generate a Blank Node to represent the person internally
	// You can create a sequence of internal IDs for the Blank Nodes
	var seq quad.Sequence
	luke := seq.Next()

	// Alternatively create a Blank Node with a random internal ID
	// luke := quad.RandomBlankNode()

	quads = append(quads, quad.Make(luke, quad.IRI(rdf.Type), quad.IRI(foaf.Person), label))
	quads = append(quads, quad.Make(luke, quad.IRI(foaf.FamilyName), "Luke", label))
	quads = append(quads, quad.Make(luke, quad.IRI(foaf.GivenName), "Skywalker", label))
	quads = append(quads, quad.Make(luke, quad.IRI(foaf.Age), 23, label))

	leia := seq.Next()

	quads = append(quads, quad.Make(leia, quad.IRI(rdf.Type), quad.IRI(foaf.Person), label))
	quads = append(quads, quad.Make(leia, quad.IRI(foaf.FamilyName), "Leia", label))
	quads = append(quads, quad.Make(leia, quad.IRI(foaf.GivenName), "Organa", label))

	quads = append(quads, quad.Make(leia, quad.IRI(foaf.Knows), luke, label))

	return quads
}

func makeQuadsWithIRIs() []quad.Quad {
	label := "people"
	quads := []quad.Quad{}

	// Create IRIs to represent the person globally, and universally
	luke := quad.IRI("https://swapi.co/resource/human/luke_skywalker")

	// Alternatively create a Blank Node with a random internal ID
	// luke := quad.RandomBlankNode()

	quads = append(quads, quad.Make(luke, quad.IRI(rdf.Type), quad.IRI(foaf.Person), label))
	quads = append(quads, quad.Make(luke, quad.IRI(foaf.FamilyName), "Luke", label))
	quads = append(quads, quad.Make(luke, quad.IRI(foaf.GivenName), "Skywalker", label))

	leia := quad.IRI("https://swapi.co/resource/human/leia_organa")

	quads = append(quads, quad.Make(leia, quad.IRI(rdf.Type), quad.IRI(foaf.Person), label))
	quads = append(quads, quad.Make(leia, quad.IRI(foaf.FamilyName), "Leia", label))
	quads = append(quads, quad.Make(leia, quad.IRI(foaf.GivenName), "Organa", label))

	quads = append(quads, quad.Make(leia, quad.IRI(foaf.Knows), luke, label))

	return quads
}

func printQuads(quads []quad.Quad) {
	fmt.Println("The details of the quads created:")
	for i, q := range quads {
		fmt.Printf("quads[%d]:\n", i)
		fmt.Printf("  subject: %s %v\n", q.Get(quad.Subject), reflect.TypeOf(q.Get(quad.Subject)))
		fmt.Printf("  predicate: %s %v\n", q.Get(quad.Predicate), reflect.TypeOf(q.Get(quad.Predicate)))
		fmt.Printf("  object: %s %v\n", q.Get(quad.Object), reflect.TypeOf(q.Get(quad.Object)))
		fmt.Printf("  label: %s %v\n\n", q.Get(quad.Label), reflect.TypeOf(q.Get(quad.Label)))
	}

	fmt.Println("The quads in NQuad representation:")
	for _, q := range quads {
		fmt.Printf("%s\n", q.NQuad())
	}
}

Run this code on Repl.it

    cd quad/writer
    go run export_nquads_to_stdout.go data

The results:

digraph cayley_graph {
	"_:n7510155278594416037" -> "<foaf:Person>" [ label = "<rdf:type>" ];
	"_:n7510155278594416037" -> "\"Luke\"" [ label = "<foaf:givenName>" ];
	"_:n7510155278594416037" -> "\"Skywalker\"" [ label = "<foaf:familyName>" ];
	"_:n7510155278594416037" -> "\"23\"^^<xsd:integer>" [ label = "<foaf:age>" ];
	"_:n7235299428451853102" -> "<foaf:Person>" [ label = "<rdf:type>" ];
	"_:n7235299428451853102" -> "_:n7510155278594416037" [ label = "<foaf:knows>" ];
	"_:n7235299428451853102" -> "\"Leia\"" [ label = "<foaf:givenName>" ];
	"_:n7235299428451853102" -> "\"Organa\"" [ label = "<foaf:familyName>" ];
}


Creator "Cayley"
graph [ directed 1
	node [ id 0 label "_:n7510155278594416037" ]
	node [ id 1 label "<foaf:Person>" ]
	edge [ source 0 target 1 label "<rdf:type>" ]
	node [ id 2 label "&quot;Luke&quot;" ]
	edge [ source 0 target 2 label "<foaf:givenName>" ]
	node [ id 3 label "&quot;Skywalker&quot;" ]
	edge [ source 0 target 3 label "<foaf:familyName>" ]
	node [ id 4 label "&quot;23&quot;^^<xsd:integer>" ]
	edge [ source 0 target 4 label "<foaf:age>" ]
	node [ id 5 label "_:n7235299428451853102" ]
	edge [ source 5 target 1 label "<rdf:type>" ]
	edge [ source 5 target 0 label "<foaf:knows>" ]
	node [ id 6 label "&quot;Leia&quot;" ]
	edge [ source 5 target 6 label "<foaf:givenName>" ]
	node [ id 7 label "&quot;Organa&quot;" ]
	edge [ source 5 target 7 label "<foaf:familyName>" ]
]


<?xml version="1.0" encoding="UTF-8"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns"   
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
         xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns 
           http://www.yworks.com/xml/schema/graphml/1.1/ygraphml.xsd"  
         xmlns:y="http://www.yworks.com/xml/graphml">

    <key id="d0" for="node" yfiles.type="nodegraphics"/>  
    <key id="d1" for="edge" yfiles.type="edgegraphics"/>  
	<graph id="G" edgedefault="directed">
		<node id="n0"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="220.0" height="30.0"/>  
              <y:Fill color="#E1E1E1" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>_:n7510155278594416037</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<node id="n1"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="130.0" height="30.0"/>  
              <y:Fill color="#FFFF99" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>&lt;foaf:Person&gt;</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n0" target="n1"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;rdf:type&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<node id="n2"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="60.0" height="30.0"/>  
              <y:Fill color="#CCFFCC" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>&#34;Luke&#34;</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n0" target="n2"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;foaf:givenName&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<node id="n3"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="110.0" height="30.0"/>  
              <y:Fill color="#CCFFCC" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>&#34;Skywalker&#34;</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n0" target="n3"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;foaf:familyName&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<node id="n4"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="190.0" height="30.0"/>  
              <y:Fill color="#CCFFCC" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>&#34;23&#34;^^&lt;xsd:integer&gt;</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n0" target="n4"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;foaf:age&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<node id="n5"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="220.0" height="30.0"/>  
              <y:Fill color="#E1E1E1" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>_:n7235299428451853102</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n5" target="n1"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;rdf:type&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<edge source="n5" target="n0"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;foaf:knows&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<node id="n6"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="60.0" height="30.0"/>  
              <y:Fill color="#CCFFCC" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>&#34;Leia&#34;</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n5" target="n6"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;foaf:givenName&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
		<node id="n7"><data key="d0">
            <y:ShapeNode>  
              <y:Geometry x="170.5" y="-15.0" width="80.0" height="30.0"/>  
              <y:Fill color="#CCFFCC" transparent="false"/>  
              <y:BorderStyle type="line" width="1.0" color="#000000"/>  
              <y:NodeLabel>&#34;Organa&#34;</y:NodeLabel>
              <y:Shape type="ellipse"/>  
            </y:ShapeNode>  
    </data></node>
		<edge source="n5" target="n7"><data key="d1">
    <y:PolyLineEdge>  
          <y:Path sx="0.0" sy="-15.0" tx="29.5" ty="0.0">  
            <y:Point x="425.0" y="0.0"/>  
          </y:Path>  
          <y:LineStyle type="line" width="1.0" color="#000000"/>  
          <y:Arrows source="none" target="standard"/>  
          <y:EdgeLabel alignment="center" backgroundColor="#FFFFFF" configuration="AutoFlippingLabel" distance="2.0" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="17.96875" horizontalTextPosition="center" iconTextGap="4" modelName="centered" preferredPlacement="anywhere" ratio="0.5" textColor="#000000" verticalTextPosition="bottom" visible="true">&lt;foaf:familyName&gt;</y:EdgeLabel>  
          <y:BendStyle smoothed="false"/>  
        </y:PolyLineEdge>  
 </data></edge>
	</graph>
</graphml>


[
	{"subject":"_:n7510155278594416037","predicate":"\u003crdf:type\u003e","object":"\u003cfoaf:Person\u003e","label":"people"},
	{"subject":"_:n7510155278594416037","predicate":"\u003cfoaf:givenName\u003e","object":"Luke","label":"people"},
	{"subject":"_:n7510155278594416037","predicate":"\u003cfoaf:familyName\u003e","object":"Skywalker","label":"people"},
	{"subject":"_:n7510155278594416037","predicate":"\u003cfoaf:age\u003e","object":"\"23\"^^\u003cxsd:integer\u003e","label":"people"},
	{"subject":"_:n7235299428451853102","predicate":"\u003crdf:type\u003e","object":"\u003cfoaf:Person\u003e","label":"people"},
	{"subject":"_:n7235299428451853102","predicate":"\u003cfoaf:knows\u003e","object":"_:n7510155278594416037","label":"people"},
	{"subject":"_:n7235299428451853102","predicate":"\u003cfoaf:givenName\u003e","object":"Leia","label":"people"},
	{"subject":"_:n7235299428451853102","predicate":"\u003cfoaf:familyName\u003e","object":"Organa","label":"people"}
]


_:n7510155278594416037 <rdf:type> <foaf:Person> "people" .
_:n7510155278594416037 <foaf:givenName> "Luke" "people" .
_:n7510155278594416037 <foaf:familyName> "Skywalker" "people" .
_:n7510155278594416037 <foaf:age> "23"^^<xsd:integer> "people" .
_:n7235299428451853102 <rdf:type> <foaf:Person> "people" .
_:n7235299428451853102 <foaf:knows> _:n7510155278594416037 "people" .
_:n7235299428451853102 <foaf:givenName> "Leia" "people" .
_:n7235299428451853102 <foaf:familyName> "Organa" "people" .

Rendered Graphviz

Rendered yEd GraphML