RDF API for PHP V0.9.3

Test: RDQL Query


This example is part of the RAP - Rdf API for PHP documentation.

1. Load a model to be queried

// Filename of an RDF document
$base="employees.rdf"

// Create a new MemModel
$model = ModelFactory::getDefaultModel();

// Load and parse document
$model->load($base);

// Show input model
$model->writeAsHtmlTable();

Output:

Base URI: employees.rdf#

Size: 36

No.

Subject

Predicate

Object

1.

Blank Node: bNode10

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#work

2.

Blank Node: bNode10

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: B.Parker@example.com

3.

Blank Node: bNode1

Resource: http://www.w3.org/2001/vcard-rdf/3.0#Family

Literal: Murphy

4.

Blank Node: bNode1

Resource: http://www.w3.org/2001/vcard-rdf/3.0#Given

Literal: Monica

5.

Blank Node: bNode2

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#work

6.

Blank Node: bNode2

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: +1 111 2222 999

7.

Blank Node: bNode3

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#work

8.

Blank Node: bNode3

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: M.Murphy@example.com

9.

Blank Node: bNode4

Resource: http://www.w3.org/2001/vcard-rdf/3.0#Family

Literal: Simpson

10.

Blank Node: bNode4

Resource: http://www.w3.org/2001/vcard-rdf/3.0#Given

Literal: George

11.

Blank Node: bNode5

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#work

12.

Blank Node: bNode5

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: +1 111 2222 101

13.

Blank Node: bNode6

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#work

14.

Blank Node: bNode6

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: G.Simpson@example.com

15.

Blank Node: bNode7

Resource: http://www.w3.org/2001/vcard-rdf/3.0#Family

Literal: Parker

16.

Blank Node: bNode7

Resource: http://www.w3.org/2001/vcard-rdf/3.0#Given

Literal: Bill

17.

Blank Node: bNode8

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#work

18.

Blank Node: bNode8

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: +1 111 2222 668

19.

Blank Node: bNode9

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#type

Resource: http://www.w3.org/2001/vcard-rdf/3.0#home

20.

Blank Node: bNode9

RDF Node: http://www.w3.org/1999/02/22-rdf-syntax-ns#value

Literal: +1 111 2212 431

21.

Resource: http://example.com/employees/BillParker/

Resource: http://sampleVocabulary.org/1.3/People#age

Literal: 33

22.

Resource: http://example.com/employees/BillParker/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#EMAIL

Blank Node: bNode10

23.

Resource: http://example.com/employees/BillParker/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#FN

Literal: Bill Parker

24.

Resource: http://example.com/employees/BillParker/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#N

Blank Node: bNode7

25.

Resource: http://example.com/employees/BillParker/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#TEL

Blank Node: bNode8

26.

Resource: http://example.com/employees/BillParker/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#TEL

Blank Node: bNode9

27.

Resource: http://example.com/employees/GeorgeSimpson/

Resource: http://sampleVocabulary.org/1.3/People#age

Literal: 41

28.

Resource: http://example.com/employees/GeorgeSimpson/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#EMAIL

Blank Node: bNode6

29.

Resource: http://example.com/employees/GeorgeSimpson/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#FN

Literal: George Simpson

30.

Resource: http://example.com/employees/GeorgeSimpson/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#N

Blank Node: bNode4

31.

Resource: http://example.com/employees/GeorgeSimpson/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#TEL

Blank Node: bNode5

32.

Resource: http://example.com/employees/MonicaMurphy/

Resource: http://sampleVocabulary.org/1.3/People#age

Literal: 29

33.

Resource: http://example.com/employees/MonicaMurphy/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#EMAIL

Blank Node: bNode3

34.

Resource: http://example.com/employees/MonicaMurphy/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#FN

Literal: Monica Murphy

35.

Resource: http://example.com/employees/MonicaMurphy/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#N

Blank Node: bNode1

36.

Resource: http://example.com/employees/MonicaMurphy/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#TEL

Blank Node: bNode2


2. Find the age of all employees, use the RdqlResultIterator for traversing the Result

Read more about RDQL Syntax.

// query string
$rdql_query = '
SELECT ?givenName, ?age
WHERE (?x, <v:age>, ?age),
      (?x, <vcard:N>, ?blank),
      (?blank, <vcard:Given>, ?givenName)
USING vcard FOR <http://www.w3.org/2001/vcard-rdf/3.0#>
      v FOR <http://sampleVocabulary.org/1.3/People#>';


//query model, get RDQLResultIterator
$rdqlIter = $model->rdqlQueryasIterator($rdql_query);

//get different Result labels as array
$result_labels=$rdqlIter->getResultLabels();
echo "<BR><b>Result Label Names:</b> ";
for ($i=0; $i <count($result_labels); $i++) echo $result_labels[$i]." ";

echo "<BR><B>Number of results:</B> ".$rdqlIter->countResults()";

//serialize result to string
echo "<BR><B>Result objects, serialized to string:</B><BR>";
while ($rdqlIter->hasNext()) {
 $curren_result=$rdqlIter->next();
 echo "<BR>";
 for ($j=0; $j <count($result_labels); $j++) echo $curren_result[$result_labels[$j]]->toString()."<BR> ";
};

Note:   The methods rdqlQuery() and rdqlQueryAsIterator() can only query their own model. If the rdql query string contains a SOURCE clause it will be ignored by the query engine.

Output:

Result Label Names: ?givenName ?age
Number of results: 3

Result objects, serialized to string:
Literal("Monica")
Literal("29")

Literal("George")
Literal("41")

Literal("Bill")
Literal("33")

 



3. Find emails of all employees (using regular expression)

// query string
$rdql_query = '
SELECT ?givenName, ?familyName, ?email
WHERE (?person <vcard:N> ?blank1)
      (?blank1 <vcard:Given> ?givenName)
      (?blank1 <vcard:Family> ?familyName)
      (?person <vcard:EMAIL> ?blank2)
      (?blank2 <rdf:value> ?email)
AND ?person ~~ "/example.com\/EMPLOYEES\//i"
USING vcard FOR <http://www.w3.org/2001/vcard-rdf/3.0#>
      v FOR <http://sampleVocabulary.org/1.3/People#>';

// query the model
$res = $model->rdqlQuery($rdql_query);

// show result
RdqlEngine::writeQueryResultAsHtmlTable($res);

Output:

No.?givenName?familyName?email
1.

Literal: Bill

Literal: Parker

Literal: B.Parker@example.com

2.

Literal: Monica

Literal: Murphy

Literal: M.Murphy@example.com

3.

Literal: George

Literal: Simpson

Literal: G.Simpson@example.com



4. Find employees over 30

// query string
$rdql_query = '
SELECT ?employee
WHERE (?x, <vcard:FN>, ?employee),
      (?x, <v:age>, ?age)
AND ?age > 30
USING vcard FOR <http://www.w3.org/2001/vcard-rdf/3.0#>
      v FOR <http://sampleVocabulary.org/1.3/People#>';

// query the model
$res = $model->rdqlQuery($rdql_query);

// show result
RdqlEngine::writeQueryResultAsHtmlTable($res);

Output:

No.?employee
1.

Literal: Bill Parker

2.

Literal: George Simpson

5. Find whose number is it: +1 111 2212 431

// query string
$rdql_query = '
SELECT ?x, ?type
WHERE (?x, <vcard:TEL>, ?tel),
      (?tel, <rdf:value>, ?telNumber)
      (?tel, <rdf:type>, ?type)
AND ?telNumber eq "+1 111 2212 431"
USING vcard FOR <http://www.w3.org/2001/vcard-rdf/3.0#>
      v FOR <http://sampleVocabulary.org/1.3/People#>';

// query the model
$res = $model->rdqlQuery($rdql_query);

// show result
RdqlEngine::writeQueryResultAsHtmlTable($res);

Output:

No.?x?type
1.

Resource: http://example.com/employees/BillParker/

Resource: http://www.w3.org/2001/vcard-rdf/3.0#home


6. Find office telephone number of all employees

// query string
$rdql_query = '
SELECT ?givenName, ?familyName, ?telNumber
WHERE (?person <vcard:N> ?blank1)
      (?blank1 <vcard:Given> ?givenName)
      (?blank1 <vcard:Family> ?familyName)
      (?person <vcard:TEL> ?blank2)
      (?blank2 <rdf:value> ?telNumber)
      (?blank2 <rdf:type> ?type)
AND ?person ~~ "/example.com\/EMPLOYEES\//i" && ?type eq <vcard:work>
USING vcard FOR <http://www.w3.org/2001/vcard-rdf/3.0#>
      v FOR <http://sampleVocabulary.org/1.3/People#>';

// query the model
$res = $model->rdqlQuery($rdql_query);

// show result
RdqlEngine::writeQueryResultAsHtmlTable($res);

Output:

No.?givenName?familyName?telNumber
1.

Literal: Monica

Literal: Murphy

Literal: +1 111 2222 999

2.

Literal: George

Literal: Simpson

Literal: +1 111 2222 101

3.

Literal: Bill

Literal: Parker

Literal: +1 111 2222 668