The SPARQL Endpoint Page can now be customized using a xsl stylesheet.

This works by adding the following line with isql:

SQL> registry_set ('sparql_endpoint_xsl', 'http://host:port/path/isparql.xsl');

where obviously host, port, path and the name isparql.xsl can be set to anything.

If the query is a CONSTRUCT or a DESCRIBE then the result set consists of a single row and a single column. The value inside is a dictionary of triples in 'long valmode'. Note that the dictionary object cannot be sent to a SQL client, say, via ODBC. The client may lose the database connection trying to fetch a result set row that contains a dictionary object. This disconnection does not disrupt the server, so the client may readily reconnect to the server, but the disconnected transaction will have been rolled back.

	See Also:
	Virtuoso ODBC RDF extensions for SPASQL

All the SPARQL protocol standard MIME types are supported by a SPARQL web service client. Moreover, SPARQL web service endpont supports additional MIME types and in some cases additional query types for standard MIME types.

Use the format parameter to select one of the following alternate output formats:

Example output of DESCRIBE in rdf+json serialization format

Example output of CONSTRUCT in rdf+json serialization format

For interoperability with clients that were developed before current versions of SPARQL protocol and format specs are issued, Virtuoso supports some obsolete variants of standard MIME types. 'text/rdf+n3', 'text/rdf+ttl', 'application/turtle' and 'application/x-turtle' are understood for TURTLE output, 'application/x-rdf+json' and 'application/rdf+json' are for "Serializing SPARQL Query Results in JSON". When a client specifies obsolete MIME type but not its standard variant, an obsolete variant is returned for interoperability.

To set SPARQL Endpoint to check if all variables in a given query are declared correctly, one should hatch the the Options "Strict checking of void variables" check-box. In that case, if a variable declaration is missing, i.e. not included in the SPARQL Query WHERE clause, then an error will be raised. For example, on attempt to execute the following query:

-- 	Options "Strict checking of void variables" check-box is checked:
select ?y
where
 {
  ?s ?p ?o
 }

since the variable ?y is not declared, the following error will be raised:

Virtuoso 37000 Error SP031: SPARQL compiler:
Variable 'y' is used in the query result set but not assigned

SPARQL query:

#output-format:text/html
define sql:signal-void-variables 1 define sql:gs-app-callback "ODS" select ?y
where
{
?s ?p ?o
}

To view SPARQL Endpoint Results page of SPARQL query execution should be used the parameter query i.e the SPARQL Protocol URL should look like:

http://cname/sparql?default-graph-uri=&query=...

Example

Suppose the following simple query:

SELECT *
WHERE
  {
    ?s ?p ?o
  }
LIMIT 10

See this example link against Virtuoso Demo Server SPARQL Endpoint with SPARQL Protocol URL.

To view the SPARQL Endpoint editor page of SPARQL query execution should be used the parameter qtxt i.e the SPARQL Protocol URL should look like:

http://cname/sparql?default-graph-uri=&qtxt=...

Example

Suppose the following simple query:

SELECT *
WHERE
  {
    ?s ?p ?o
  }
LIMIT 10

Suppose also this results page link against Virtuoso Demo Server SPARQL Endpoint with SPARQL Protocol URL.

Replace the parameter name query with qtxt .

Access the new link , which should present the SPARQL Endpoint Editor page with "Query Text" area filled in with the SPARQL Query from above.

Virtuoso also provides SPARQL protocol client APIs in Virtuoso PL, so you can communicate with SPARQL Query Services from Virtuoso stored procedures. The APIs are as follows:

Starting with version 6, Virtuoso offers a partial query evaluation feature that guarantees answers to arbitrary queries within a fixed time. This is intended for use in publicly available SPARQL or SQL end points on large databases. This enforces a finite duration to all queries and will strive to return meaningful partial results. Thus this provides the same security as a transaction timeout but will be more user friendly since results will generally be returned, also for aggregate queries. Outside of a public query service, this may also be handy when exploring a large data set with unknown properties.

The feature is activated with the statement

set result_timeout == <expression>;

Find more detailed information in the Anytime Queries section.

SPARQL define output:format "NT"
CONSTRUCT { ?s a ?t }
FROM virtrdf:
WHERE { ?s a ?t };

Virtuoso reserves the path '/sparql-auth/' for a SPARQL service supporting authenticated SPARUL. This endpoint allows specific SQL accounts to perform SPARUL over the SPARQL protocol. To be allowed to login via SQL or ODBC and update physical triples, a user must be granted "SPARQL_UPDATE" privileges. To grant this role:

Note that if a table is used in an Linked Data View, and this table is not granted to SPARQL_SELECT permission (or SPARQL_UPDATE, which implicitly confers SPARQL_SELECT), then all SELECTs on a graph defined by an Linked Data View will return an access violation error as the user account has no permissions to read the table. The user must have appropriate privileges on all tables included in an Linked Data View in order to be able to select on all graphs.

Virtuoso web service endpoints may provide different default configurations for different host names mentioned in an HTTP request. Host name configuration for SPARQL web service endpoints can be managed via the table DB.DBA.SYS_SPARQL_HOST .

create table DB.DBA.SYS_SPARQL_HOST (
  SH_HOST	varchar not null primary key, -- host mask
  SH_GRAPH_URI varchar,                 -- default graph uri
  SH_USER_URI	varchar,                  -- reserved for any use in applications
  SH_BASE_URI varchar,                  -- for future use (not used currently) to set BASE in sparql queries. Should be NULL for now.
  SH_DEFINES long varchar,              -- additional defines for requests
  PRIMARY KEY (SH_HOST)
)

You can find detailed descriptions of the table columns here . Also, please read these notes on managing public web service endpoints.

Virtuoso 5.0.7 introduced a new "SPARQL_SPONGE" role which can be assigned specifically for controlling Sponger middleware services which perform writes and graph creation in the RDF Quad Store. This role only allows updates through the Sponger. Quad Store updates via any other route require granting the SPARQL_UPDATE role.

Virtuoso 5.0.11 onwards added three new methods for securing SPARQL endpoints that include:

Each of these authentication methods is associated with a purpose specific default SPARQL endpoint along the following lines:

Note: sparql-ssl is alias of sparql-webid.

The Virtuoso Authentication Server offers a UI with options for managing:

Virtuoso Authentication Server can be installed by downloading and installing the conductor_dav.vad package.

The Authentication UI is accessible from the Conductor UI -> Linked Data -> Access Control -> SPARQL-WebID. Here is sample scenario:

OAuth provides a secure data transmission level mechanism for your SPARQL endpoint. It enables you to interact securely with your RDF database from a variety of locations. It also allows you to provide controlled access to private data to selected users.

Virtuoso OAuth Server can be installed by downloading and installing the ods_framework_dav.vad package. The OAuth UI is accessible from the URL http://cname:port/oauth

A user must have SQL privileges in order to run secured SPARQL statements.

Here is a sample scenario:

WebID Protocol is an implementation of a conceptual authentication and authorization protocol that links a Web ID to a public key, to create a global decentralized/distributed, and open yet secure authentication system that functions with existing browsers.

To use WebID Protocol, download and install the conductor_dav.vad VAD package. Once installed, to access the WebID Protocol ACLs UI, go to URL http://cname:port/conductor -> Linked Data -> Access Controls -> SPARQL-WebID .

Figure 16.24. WebID

Configuring WebID Protocol ACLs is with a WebID Protocol certificate and a Web ID allows secure SPARQL queries to be performed against a Virtuoso SPARQL-WebID endpoint and viewing of the query results. The SPARQL-WebID endpoint URL is of the form https://cname:port/sparql-webid

Note: SPARQL-SSL is alias of SPARQL-WebID.

See sample example how to configure a sample WebID Protocol ACL are outlined below:

	See Also:
	WebID Protocol ODBC Login

The following section describes the basic steps for setting up an SSL protected and WebID based SPARQL Endpoint (SPARQL-WebID). The guide also covers the use of Virtuoso PL functions and the Virtuoso Conductor for SPARQL endpoint creation and configuration. It also covers the use of cURL for exercising the newly generated SPARQL-SSL endpoint. Note: SPARQL-SSL is alias of SPARQL-WebID.

	See Also:
	Demo Example Using HTTP client to perform WebID Protocol connection.

curl -F "query=SELECT DISTINCT ?p FROM <http://demo.openlinksw.com/DAV/home/demo/rdf_sink/> WHERE {?s ?p ?o}" http://demo.openlinksw.com/sparql

The result should be:

<?xml version="1.0" ?>
<sparql xmlns="http://www.w3.org/2005/sparql-results#" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.w3.org/2001/sw/DataAccess/rf1/result2.xsd">
 <head>
  <variable name="p"/>
 </head>
 <results distinct="false" ordered="true">
  <result>
   <binding name="p"><uri>http://www.w3.org/1999/02/22-rdf-syntax-ns#type</uri></binding>
  </result>
  <result>
   <binding name="p"><uri>http://xmlns.com/foaf/0.1/nick</uri></binding>
  </result>
  <result>
   <binding name="p"><uri>http://xmlns.com/foaf/0.1/name</uri></binding>
  </result>
  <result>
   <binding name="p"><uri>http://xmlns.com/foaf/0.1/homepage</uri></binding>
  </result>
  <result>
   <binding name="p"><uri>http://xmlns.com/foaf/0.1/knows</uri></binding>
  </result>
  <result>
   <binding name="p"><uri>http://xmlns.com/foaf/0.1/workplaceHomepage</uri></binding>
  </result>
  <result>
   <binding name="p"><uri>http://xmlns.com/foaf/0.1/mbox</uri></binding>
  </result>
 </results>
</sparql>

Further example SPARQL queries:

curl -F "query=SELECT DISTINCT ?Concept FROM <http://dbpedia.org> WHERE {?s a ?Concept} LIMIT 10" http://dbpedia.org/sparql

curl -F "query=SELECT DISTINCT ?Concept FROM <http://example.com/dataspace/person/kidehen> WHERE {?s a ?Concept} LIMIT 10" http://demo.openlinksw.com/sparql

curl -F "query=SELECT DISTINCT ?Concept FROM <http://data.openlinksw.com/oplweb/product_family/virtuoso> WHERE {?s a ?Concept} LIMIT 10" http://demo.openlinksw.com/sparql

curl -F "query=SELECT DISTINCT ?Concept FROM <http://openlinksw.com/dataspace/organization/openlink> WHERE {?s a ?Concept} LIMIT 10" http://demo.openlinksw.com/sparql

$ curl -H "Accept: text/rdf+n3"  --cert test.pem -k https://demo.openlinksw.com/dataspace/person/demo
Enter PEM pass phrase: *****
@prefix rdf:    <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix ns1:    <https://demo.openlinksw.com/dataspace/demo/socialnetwork/demo%27s%20AddressBook/1046#> .
@prefix foaf:   <http://xmlns.com/foaf/0.1/> .
ns1:this        rdf:type        foaf:Person .
@prefix ns3:    <http://www.pipian.com/rdf/tami/juliette.n3#> .
ns3:juliette    rdf:type        foaf:Document .
@prefix ns4:    <https://demo.openlinksw.com/dataspace/person/> .
ns4:demo        rdf:type        foaf:PersonalProfileDocument .
@prefix ns5:    <https://demo.openlinksw.com/dataspace/person/demo#> .
@prefix geo:    <http://www.w3.org/2003/01/geo/wgs84_pos#> .
ns5:based_near  rdf:type        geo:Point .
@prefix ns7:    <https://demo.openlinksw.com/dataspace/demo/socialnetwork/demo%27s%20AddressBook/1042#> .
ns7:this        rdf:type        foaf:Person .
ns5:this        rdf:type        foaf:Person .
@prefix ns8:    <https://demo.openlinksw.com/dataspace/person/demo/online_account/> .
@prefix sioc:   <http://rdfs.org/sioc/ns#> .
ns8:demo        rdf:type        sioc:User .
@prefix ns10:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/myAddressBook/1001#> .
ns10:this       rdf:type        foaf:Person .
@prefix ns11:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/demo%27s%20AddressBook/1045#> .
ns11:this       rdf:type        foaf:Person .
@prefix ns12:   <https://demo.openlinksw.com/dataspace/demo#> .
ns12:this       rdf:type        sioc:User .
ns5:org rdf:type        foaf:Organization .
@prefix ns13:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/demo%27s%20AddressBook/1048#> .
ns13:this       rdf:type        foaf:Person .
@prefix ns14:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/myAddressBook/1001#this#> .
ns14:org        rdf:type        foaf:Organization .
@prefix ns15:   <https://demo.openlinksw.com/dataspace/person/imitko#> .
ns15:this       rdf:type        foaf:Person .
@prefix ns16:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/myAddressBook/1049#> .
ns16:this       rdf:type        foaf:Person .
@prefix ns17:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/myAddressBook/1000#> .
ns17:this       rdf:type        foaf:Person .
ns8:MySpace     rdf:type        sioc:User .
@prefix ns18:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/demo%27s%20AddressBook/1044#> .
ns18:this       rdf:type        foaf:Person .
@prefix dc:     <http://purl.org/dc/elements/1.1/> .
ns4:demo        dc:title        "demo demo's FOAF file" .
ns14:org        dc:title        "OpenLink" .
ns5:org dc:title        "OpenLink" .
ns18:this       foaf:name       "Kingsley Idehen" .
ns13:this       foaf:name       "Juliette" .
ns17:this       foaf:name       "Kingsley Idehen" .
ns5:this        foaf:name       "demo demo" .
ns15:this       foaf:name       "Mitko Iliev" .
ns10:this       foaf:name       "test test12" .
@prefix rdfs:   <http://www.w3.org/2000/01/rdf-schema#> .
ns5:this        rdfs:seeAlso    ns4:demo .
ns15:this       rdfs:seeAlso    ns4:imitko .
ns4:demo        foaf:maker      ns5:this .
ns15:this       foaf:nick       "imitko" .
ns7:this        foaf:nick       "Orri Erling" .
ns13:this       foaf:nick       "Juliette" .
ns10:this       foaf:nick       "test1" .
ns5:this        foaf:nick       "demo" .
ns18:this       foaf:nick       "Kingsley" .
ns17:this       foaf:nick       "Kingsley" .
ns16:this       foaf:nick       "test2" .
ns1:this        foaf:nick       "TEST" .
ns11:this       foaf:nick       "TEST" .
ns5:this        foaf:holdsAccount       ns8:demo ,
                ns8:MySpace ,
                ns12:this .
@prefix ns21:   <http://example.com/dataspace/person/imitko#> .
ns5:this        foaf:knows      ns21:this ,
                ns17:this ,
                ns16:this ,
                ns3:juliette ,
                ns10:this ,
                ns7:this .
@prefix ns22:   <http://example.com/dataspace/person/kidehen#> .
ns5:this        foaf:knows      ns22:this ,
                ns18:this ,
                ns11:this ,
                ns1:this .
@prefix ns23:   <http://bblfish.net/people/henry/card#me\u0020> .
ns5:this        foaf:knows      ns23: ,
                ns13:this ,
                ns15:this ;
        foaf:firstName  "demo" ;
        foaf:family_name        "demo" ;
        foaf:gender     "male" ;
        foaf:icqChatID  "125968" ;
        foaf:msnChatID  "45demo78" ;
        foaf:aimChatID  "demo1234" ;
        foaf:yahooChatID        "demo678" ;
        foaf:based_near ns5:based_near .
@prefix ns24:   <http://www.openlinksw.com> .
ns5:this        foaf:workplaceHomepage  ns24: .
ns5:org foaf:homepage   ns24: .
ns5:this        foaf:homepage   ns24: .
ns14:org        foaf:homepage   ns24: .
ns4:demo        foaf:primaryTopic       ns5:this .
ns5:based_near  geo:lat "47.333332" ;
        geo:long        "13.333333" .
@prefix rdf:    <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix ns1:    <https://demo.openlinksw.com/dataspace/demo#> .
@prefix foaf:   <http://xmlns.com/foaf/0.1/> .
ns1:this        rdf:type        foaf:OnlineAccount .
@prefix ns3:    <https://demo.openlinksw.com/dataspace/person/demo/online_account/> .
ns3:MySpace     rdf:type        foaf:OnlineAccount .
ns3:demo        rdf:type        foaf:OnlineAccount .
@prefix ns4:    <https://demo.openlinksw.com/dataspace/person/demo#> .
ns4:this        foaf:holdsAccount       ns3:MySpace ,
                ns1:this ,
                ns3:demo .
@prefix vcard:  <http://www.w3.org/2001/vcard-rdf/3.0#> .
ns4:this        vcard:ADR       ns4:addr .
ns4:addr        vcard:Country   "United States" ;
        vcard:Locality  "New York" ;
        vcard:Region    "Nebraska" .
@prefix ns6:    <http://myspace.com> .
ns3:MySpace     foaf:accountServiceHomepage     ns6: .
@prefix ns7:    <skype:demo?> .
ns3:demo        foaf:accountServiceHomepage     ns7:chat ;
        foaf:accountName        "demo" .
ns3:MySpace     foaf:accountName        "MySpace" .
@prefix ns8:    <http://vocab.org/bio/0.1/> .
ns4:this        ns8:olb "this is short resume of user Demo." .
@prefix ns9:    <https://demo.openlinksw.com/dataspace/> .
ns4:this        foaf:openid     ns9:demo ;
        ns8:keywords    "demo, openlinksw, virtuoso, weblog, rdf" .
@prefix foaf:   <http://xmlns.com/foaf/0.1/> .
@prefix ns1:    <https://demo.openlinksw.com/dataspace/demo/subscriptions/> .
@prefix ns2:    <https://demo.openlinksw.com/dataspace/person/demo#> .
ns1:DemoFeeds   foaf:maker      ns2:this .
@prefix ns3:    <https://demo.openlinksw.com/dataspace/demo/community/> .
ns3:demoCommunity       foaf:maker      ns2:this .
@prefix ns4:    <https://demo.openlinksw.com/dataspace/demo/eCRM/demo%27s%20eCRM> .
ns4:    foaf:maker      ns2:this .
@prefix ns5:    <https://demo.openlinksw.com/dataspace/demo/calendar/> .
ns5:mycalendar  foaf:maker      ns2:this .
@prefix ns6:    <https://demo.openlinksw.com/dataspace/demo/photos/> .
ns6:MyGallery   foaf:maker      ns2:this .
@prefix ns7:    <https://demo.openlinksw.com/dataspace/demo/briefcase/> .
ns7:mybriefcase foaf:maker      ns2:this .
@prefix ns8:    <https://demo.openlinksw.com/dataspace/demo/wiki/> .
ns8:ESBWiki     foaf:maker      ns2:this .
@prefix ns9:    <https://demo.openlinksw.com/dataspace/demo/bookmark/> .
ns9:mybookmarks foaf:maker      ns2:this .
@prefix ns10:   <https://demo.openlinksw.com/dataspace/demo/weblog/> .
ns10:myblog     foaf:maker      ns2:this .
@prefix ns11:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/demo%27s%20AddressBook> .
ns11:   foaf:maker      ns2:this .
@prefix ns12:   <https://demo.openlinksw.com/dataspace/demo/community/demo%27s%20Community> .
ns12:   foaf:maker      ns2:this .
ns8:mywiki      foaf:maker      ns2:this .
@prefix ns13:   <https://demo.openlinksw.com/dataspace/demo/eCRM/demo%20demo%27s%20eCRM> .
ns13:   foaf:maker      ns2:this .
@prefix ns14:   <https://demo.openlinksw.com/dataspace/demo/polls/> .
ns14:mypolls    foaf:maker      ns2:this .
@prefix ns15:   <https://demo.openlinksw.com/dataspace/demo/socialnetwork/> .
ns15:myAddressBook      foaf:maker      ns2:this .
ns3:SP2 foaf:maker      ns2:this .
ns2:this        foaf:made       ns11: ,
                ns4: ,
                ns3:demoCommunity ,
                ns12: ,
                ns15:myAddressBook ,
                ns10:myblog ,
                ns9:mybookmarks ,
                ns7:mybriefcase ,
                ns5:mycalendar ,
                ns14:mypolls ,
                ns8:mywiki ,
                ns1:DemoFeeds ,
                ns8:ESBWiki ,
                ns6:MyGallery ,
                ns3:SP2 ,
                ns13: .
@prefix rdfs:   <http://www.w3.org/2000/01/rdf-schema#> .
ns9:mybookmarks rdfs:label      "demo demo's Bookmarks" .
ns15:myAddressBook      rdfs:label      "demo demo's AddressBook" .
ns4:    rdfs:label      "demo demo's eCRM" .
ns12:   rdfs:label      "demo's Community" .
ns14:mypolls    rdfs:label      "demo demo's Polls" .
ns13:   rdfs:label      "demo demo's eCRM Description" .
ns8:mywiki      rdfs:label      "demo demo's Wiki" .
ns7:mybriefcase rdfs:label      "demo demo's Briefcase" .
ns1:DemoFeeds   rdfs:label      "demo demo's Feeds" .
ns10:myblog     rdfs:label      "demo's Weblog" .
ns5:mycalendar  rdfs:label      "demo demo's Calendar" .
ns11:   rdfs:label      "demo demo's AddressBook" .
ns6:MyGallery   rdfs:label      "demo demo's Gallery" .
ns8:ESBWiki     rdfs:label      "demo demo's Wiki" .
ns3:demoCommunity       rdfs:label      "demo demo's Community" .
ns3:SP2 rdfs:label      "demo demo's Community" .
@prefix rdf:    <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix ns1:    <https://demo.openlinksw.com/dataspace/person/demo#> .
@prefix ns2:    <http://www.w3.org/ns/auth/rsa#> .
ns1:cert        rdf:type        ns2:RSAPublicKey .
@prefix dc:     <http://purl.org/dc/elements/1.1/> .
@prefix ns4:    <https://demo.openlinksw.com/dataspace/person/demo/projects#ods%20project> .
ns4:    dc:title        "ods project" .
@prefix foaf:   <http://xmlns.com/foaf/0.1/> .
ns4:    foaf:maker      ns1:this .
ns1:this        foaf:made       ns4: .
@prefix ns6:    <http://www.w3.org/ns/auth/cert#> .
ns1:cert        ns6:identity    ns1:this ;
        ns2:modulus     ns1:cert_mod .
ns1:cert_mod    ns6:hex "b8edefa13092d05e85257d6be0aca54218091278583f1d18759c4bced0007948fa6e920018abc3c30b8885d303ec2e679f3a7c15036d38452ddd9ebfcbb41
e1bd08dca66b7737b744fd9e441ebefa425311363711714cd0fe3b334a79ce50be9eb3443193bcbf2f1486481e775382f1a1792a2a8438543ca6f478c3b13c5db2a7f9a12a9a5aed5ec498
6be0169a1859d027170812a28914d158fb76a5933f11777a06c8db64d10f7c02900c4bb4bbf2d24c0e34c6ca135fdb5e05241bc029196ceef13a2006f07d1800f17762c0cfe05b3dac3042
09e1b7a3973122e850e96fcd0396544f82f0b11a46f0d868ba0f3d8efd957e7ef224871905a06c3c5d85ac9" .
ns1:cert        ns2:public_exponent     ns1:cert_exp .
ns1:cert_exp    ns6:decimal     "65537" .
@prefix rdf:    <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix ns1:    <https://demo.openlinksw.com/dataspace/person/demo#> .
@prefix ns2:    <http://vocab.org/bio/0.1/> .
ns1:event       rdf:type        ns2:Birth .
@prefix foaf:   <http://xmlns.com/foaf/0.1/> .
@prefix ns4:    <mailto:demo@openlinksw.com> .
ns1:this        foaf:mbox       ns4: ;
        foaf:birthday   "01-01" .
@prefix dc:     <http://purl.org/dc/elements/1.1/> .
ns1:event       dc:date "1968-01-01" .
ns1:this        ns2:event       ns1:event .

Note: this is just an example as token had expired already. You can go to this section to see how to interact with our Virtuoso UI.

$ curl "http://demo.openlinksw.com/oauth/sparql.vsp?debug=on&default-graph-uri=&format=text%2Fhtml&oauth_consumer_key=27f105a327f5f23163e0636f78901
8dacdd70bb5&oauth_nonce=a14d43339fcb2638&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1242106643&oauth_token=42e2af4d9264ef42521c1010aff99f60a8
ee95a2&oauth_version=1.0&query=select%20distinct%20%3FURI%20%3FObjectType%20where%20%7B%3FURI%20a%20%3FObjectType%7D%20limit%2050&oauth_signature=C
w9yJ2saU1vgHuFxWcughai5cZY%3D"
<table class="sparql" border="1">
  <tr>
    <th>URI</th>
    <th>ObjectType</th>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarchar</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarchar-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarbinary</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarbinary-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-uri</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-uri-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-uri</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-uri-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-doubleprecision</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-doubleprecision-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-date</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-date-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-datetime</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-datetime-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#multipart-uri</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#multipart-uri-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#multipart-uri-fn-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#multipart-literal-fn-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-uri-fn</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-uri-fn-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-uri-fn</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-uri-fn-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-literal-fn</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-literal-fn-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-literal-fn</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-integer-literal-fn-nullable</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.w3.org/1999/02/22-rdf-syntax-ns#type</td>
    <td>http://www.w3.org/1999/02/22-rdf-syntax-ns#Property</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-nullable-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank-nullable-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#default-nullable-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-nullable-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarchar-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarchar-nullable-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarbinary-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-longvarbinary-nullable-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
  <tr>
    <td>http://www.openlinksw.com/virtrdf-data-formats#sql-varchar-uri-SuperFormats</td>
    <td>http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat</td>
  </tr>
</table>

Go to the sparql endpoint UI: i.e. go to http://host:port/sparql

For the Default Graph URI enter: http://www.w3.org/2001/sw/DataAccess/proto-tests/data/construct/simple-data.rdf

Select "Retrieve remote RDF data for all missing source graphs".

For the query text enter:

SELECT * WHERE {?s ?p ?o}

Click the "Run Query" button.

The query results, shown below, are cached locally ( network resources being fetched ). The remote RDF data is saved in the local RDF quad store as graph http://www.w3.org/2001/sw/DataAccess/proto-tests/data/construct/simple-data.rdf

s  	                                  p  	                                           o
http://www.example/jose/foaf.rdf#jose 	  http://www.w3.org/1999/02/22-rdf-syntax-ns#type  http://xmlns.com/foaf/0.1/Person
http://www.example/jose/foaf.rdf#jose 	  http://xmlns.com/foaf/0.1/nick 	           Jo
http://www.example/jose/foaf.rdf#jose 	  http://xmlns.com/foaf/0.1/name 	           Jose Jimen~ez
http://www.example/jose/foaf.rdf#jose 	  http://xmlns.com/foaf/0.1/knows 	           http://www.example/jose/foaf.rdf#juan
http://www.example/jose/foaf.rdf#jose 	  http://xmlns.com/foaf/0.1/homepage 	           http://www.example/jose/
http://www.example/jose/foaf.rdf#jose 	  http://xmlns.com/foaf/0.1/workplaceHomepage 	   http://www.corp.example/
http://www.example/jose/foaf.rdf#kendall  http://xmlns.com/foaf/0.1/knows                  http://www.example/jose/foaf.rdf#edd
http://www.example/jose/foaf.rdf#julia 	  http://www.w3.org/1999/02/22-rdf-syntax-ns#type  http://xmlns.com/foaf/0.1/Person
http://www.example/jose/foaf.rdf#julia 	  http://xmlns.com/foaf/0.1/mbox 	           mailto:julia@mail.example
http://www.example/jose/foaf.rdf#juan 	  http://www.w3.org/1999/02/22-rdf-syntax-ns#type  http://xmlns.com/foaf/0.1/Person
http://www.example/jose/foaf.rdf#juan 	  http://xmlns.com/foaf/0.1/mbox 	           mailto:juan@mail.example

Now let's take the CONSTRUCT query:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX myfoaf: <http://www.example/jose/foaf.rdf#>
CONSTRUCT
  { myfoaf:jose foaf:depiction <http://www.example/jose/jose.jpg>.
    myfoaf:jose foaf:schoolHomepage <http://www.edu.example/>.
    ?s ?p ?o.
  }
FROM <http://www.w3.org/2001/sw/DataAccess/proto-tests/data/construct/simple-data.rdf>
WHERE
  {
    ?s ?p ?o. myfoaf:jose foaf:nick "Jo".
    FILTER ( ! (?s = myfoaf:kendall && ?p = foaf:knows && ?o = myfoaf:edd )
    && ! ( ?s = myfoaf:julia && ?p = foaf:mbox && ?o = <mailto:julia@mail.example> )
    && ! ( ?s = myfoaf:julia && ?p = rdf:type && ?o = foaf:Person))
  }

From an HTTP client, issue the GET command with the above query added as a URL-encoded parameter value:

GET -e -s http://host:port/sparql/?query=PREFIX+rdf%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0D%0APREFIX+foaf%3A+%3Chttp%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2F%3E%0D%0APREFIX+myfoaf%3A+%3Chttp%3A%2F%2Fwww.example%2Fjose%2Ffoaf.rdf%23%3E%0D%0A%0D%0ACONSTRUCT+%7B+myfoaf%3Ajose+foaf%3Adepiction+%3Chttp%3A%2F%2Fwww.example%2Fjose%2Fjose.jpg%3E.%0D%0A++++++++++++myfoaf%3Ajose+foaf%3AschoolHomepage+%3Chttp%3A%2F%2Fwww.edu.example%2F%3E.%0D%0A++++++++++++%3Fs+%3Fp+%3Fo.%7D%0D%0AFROM+%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2Fsw%2FDataAccess%2Fproto-tests%2Fdata%2Fconstruct%2Fsimple-data.rdf%3E%0D%0AWHERE+%7B+%3Fs+%3Fp+%3Fo.+myfoaf%3Ajose+foaf%3Anick+%22Jo%22.%0D%0A+++++++FILTER+%28+%21+%28%3Fs+%3D+myfoaf%3Akendall+%26%26+%3Fp+%3D+foaf%3Aknows+%26%26+%3Fo+%3D+myfoaf%3Aedd+%29%0D%0A++++++++++++++%26%26+%21+%28+%3Fs+%3D+myfoaf%3Ajulia+%26%26+%3Fp+%3D+foaf%3Ambox+%26%26+%3Fo+%3D+%3Cmailto%3Ajulia%40mail.example%3E+%29%0D%0A++++++++++%26%26+%21+%28+%3Fs+%3D+myfoaf%3Ajulia+%26%26+%3Fp+%3D+rdf%3Atype+%26%26+%3Fo+%3D+foaf%3APerson%29%29%0D%0A%7D%0D%0A&format=application%2Frdf%2Bxml

The request response will be similar to:

200 OK
Connection: close
Date: Fri, 28 Dec 2007 10:06:14 GMT
Accept-Ranges: bytes
Server: Virtuoso/05.00.3023 (Win32) i686-generic-win-32  VDB
Content-Length: 2073
Content-Type: application/rdf+xml; charset=UTF-8
Client-Date: Fri, 28 Dec 2007 10:06:14 GMT
Client-Peer: 83.176.40.177:port
Client-Response-Num: 1

<?xml version="1.0" encoding="utf-8" ?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#juan"><ns0pred:mbox xmlns:ns0pred="http://xmlns.com/foaf/0.1/" rdf:resource="mailto:juan@mail.example"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:schoolHomepage xmlns:ns0pred="http://xmlns.com/foaf/0.1/" rdf:resource="http://www.edu.example/"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:type xmlns:ns0pred="http://www.w3.org/1999/02/22-rdf-syntax-ns#" rdf:resource="http://xmlns.com/foaf/0.1/Person"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:homepage xmlns:ns0pred="http://xmlns.com/foaf/0.1/" rdf:resource="http://www.example/jose/"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#juan"><ns0pred:type xmlns:ns0pred="http://www.w3.org/1999/02/22-rdf-syntax-ns#" rdf:resource="http://xmlns.com/foaf/0.1/Person"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:workplaceHomepage xmlns:ns0pred="http://xmlns.com/foaf/0.1/" rdf:resource="http://www.corp.example/"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:nick xmlns:ns0pred="http://xmlns.com/foaf/0.1/">Jo</ns0pred:nick></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:depiction xmlns:ns0pred="http://xmlns.com/foaf/0.1/" rdf:resource="http://www.example/jose/jose.jpg"/></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:name xmlns:ns0pred="http://xmlns.com/foaf/0.1/">Jose Jime?+ez</ns0pred:name></rdf:Description>
<rdf:Description rdf:about="http://www.example/jose/foaf.rdf#jose"><ns0pred:knows xmlns:ns0pred="http://xmlns.com/foaf/0.1/" rdf:resource="http://www.example/jose/foaf.rdf#juan"/></rdf:Description>
</rdf:RDF>
Done

The following example shows how to extract a part of a literal as a variable for use in a numeric comparison using SPARQL

Suppose there are the following triples inserted:

SQL>SPARQL INSERT INTO GRAPH <http://mygraph.com> {  <:a>
                                                     <:p>
                                                     "123 abc" };
callret-0
VARCHAR
_______________________________________________________________________________

Insert into <http://mygraph.com>, 1 triples -- done

1 Rows. -- 30 msec.
SQL>SPARQL INSERT INTO GRAPH <http://mygraph.com> {  <:a>
                                                     <:p>
                                                     "234 abc" };
callret-0
VARCHAR
_______________________________________________________________________________

Insert into <http://mygraph.com>, 1 triples -- done

1 Rows. -- 0 msec.

In order to extract the numeric part, and then do a numeric (<.>,=), you can use atoi (), atol or atof in the filter:

SQL>SPARQL
SELECT *
FROM <http://mygraph.com>
WHERE
  {
    ?s ?p ?o . filter (bif:atoi (?o) > 130)
  };
s        p         o
VARCHAR  VARCHAR   VARCHAR
___________________________________

:a       :p        234 abc

1 Rows. -- 10 msec.

See details here how to define rule context that is initialized from the contents of a given graph.