dotnetrdf-support

Re: [dotNetRDF-Support] DELETE QUERY

[Glen W. <gle...@bc...>]

Thanks Rob,

 

FYI the TripleStore Writers do not work with VB.NET WinForm applications

http://www.vbforums.com/showthread.php?t=552398

 

 

Therefore ... apologies ... for what is about to follow ...

 

This is meant to delete the original triple ...

            szSPARQLDelete = szPrefix & "DELETE DATA {" & _

            szSubject & " " & szPredicate & " " & szObject & "}"

            aTripleStore.ExecuteUpdate(szSPARQLDelete)

 

            i = InStr(szObject, "^^")

            szObject = szLiteral '& Mid$(szObject, i) ' .substring seems to
return 1 char short

            'nObject = OIMGraph.CreateLiteralNode(szObject)

 

'and replace it with the new value

 

            szSPARQLInsert = szPrefix & "INSERT DATA {" & _

            szSubject & " " & szPredicate & " " & szObject & "}"

            'OIMGraph.Assert(New Triple(nSubject, nPredicate, nObject))

            aTripleStore.ExecuteUpdate(szSPARQLInsert)

            ' TripleStoreWriters all cause an issue with WinForms

            '            Dim rdfWriter As New TriGWriter

            '            aTripleStore.SaveToFile("d:\data\testing.trig",
rdfWriter)

            '           Dim rdfWriterX As New TriXWriter

            '          aTripleStore.SaveToFile("d:\data\testing.trix",
rdfWriter)

            '         Dim rdfWriterN As New NQuadsWriter

            '        aTripleStore.SaveToFile("d:\data\testing.trin",
rdfWriterN)

            ' so we need to create a graph from the triplestore !!

            SaveRDF("d:\data\testing.owl", aTripleStore)

        End If

    End Sub

 

    Public Sub SaveRDF(ByVal szFilename As String, ByVal aTripleStore As
TripleStore)

        ' aTripleStore.SaveToFile(szFilename) ha if only

        Dim rdfWriter As New RdfXmlWriter

 

        Dim sparqlparser As New SparqlQueryParser

        Dim query As SparqlQuery

        Dim results As Object

        query = sparqlparser.ParseFromString("CONSTRUCT { ?s ?p ?o } WHERE
{?s ?p ?o}")

        results = aTripleStore.ExecuteQuery(query)

        If (results.GetType.ToString = "VDS.RDF.Graph") Then

            rdfWriter.Save(results, szFilename)

 

        End If

 

 

    End Sub

 

All runs .... but ...

note the edited triple

  <ns0:Thing
rdf:about="http://example.org/data#GATE_VALVE.DGNEC__1543070000__ECXA__2.DRY
_WEIGHT">

    <ns63:R10528152386 xmlns:ns63="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R39123699723" />

    <ns64:R11450580697 xmlns:ns64="http://tpl.rdlfacade.org/data#"
rdf:resource="http://example.org/data#GATE_VALVE.DGNEC__1543070000__ECXA__2"
/>

    <ns65:R56806886394 xmlns:ns65="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R66709707623" />

    <ns66:R65789235245 xmlns:ns66="http://tpl.rdlfacade.org/data#"
rdf:datatype="&xsd;float">0</ns66:R65789235245>

    <rdf:type rdf:resource="http://tpl.rdlfacade.org/data#R33612674560" />

    <xsd:R65789235245 rdf:datatype="&xsd;integer">70</xsd:R65789235245>

  </ns0:Thing>

 

compared to an unedited triple

  <ns0:Thing
rdf:about="http://example.org/data#HORIZONTAL_CENTRIFUGAL_PUMP.DGNEC__151607
0000__ECXA__2.DRY_WEIGHT">

    <ns136:R10528152386 xmlns:ns136="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R39123699723" />

    <ns137:R11450580697 xmlns:ns137="http://tpl.rdlfacade.org/data#"
rdf:resource="http://example.org/data#HORIZONTAL_CENTRIFUGAL_PUMP.DGNEC__151
6070000__ECXA__2" />

    <ns138:R56806886394 xmlns:ns138="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R66709707623" />

    <ns139:R65789235245 xmlns:ns139="http://tpl.rdlfacade.org/data#"
rdf:datatype="&xsd;float">0</ns139:R65789235245>

    <rdf:type rdf:resource="http://tpl.rdlfacade.org/data#R33612674560" />

  </ns0:Thing>

 

the original value and new value are stored ...

 

Note also the nsxxx peculiarity ...

 

Glen

 

 

 

 

From: Rob Vesse [mailto:rv...@do...] 
Sent: 21 November 2011 17:40
To: Glen Worrall
Subject: RE: DELETE QUERY

 

Hi Glen

SPARQL Query and Update are two separate standards and so the library
handles them separately.  If you want to run updates then you need to use
the ExecuteUpdate() method instead.  See [1] for alternative ways to apply
updates.

If you want to create typed literals then you need to use the two argument
version of CreateLiteralNode() which takes a URI as the second argument for
the datatype.  Or if you have .Net primitive types you can use the
ToLiteral() extension methods to turn these directly into literals with
appropriate types.

SparqlGUI was designed as a query only tool, I may add update to it in the
future but currently it does not support this.

If you have further questions please let me know,

Rob Vesse

[1]: http://www.dotnetrdf.org/content.asp?pageID=Updating%20with%20SPARQL

 

  _____  

From: "Glen Worrall" <gle...@bc...>
Sent: Monday, November 21, 2011 9:13 AM
To: rv...@do...
Subject: RE: DELETE QUERY

Hi Rob,

Just to let you know I have been trying this with other options ...

        If szSubject <> "" Then

            szPrefix = ""

            ' seems that the subject. predicate, object MUST have a
qualifier ... !!!

            iPos = InStr(szSubject, "#")

            szQualifier = Mid$(szSubject, 1, iPos)

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            'szPrefix = "PREFIX q1: <" & szQualifier & "> "

            szSubject = szNS & ":" & Mid$(szSubject, iPos + 1)

            iPos = InStr(szPredicate, "#")

            szQualifier = Mid$(szPredicate, 1, iPos)

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            'szPrefix = szPrefix & "PREFIX q2: <" & szQualifier & "> "

            szPredicate = szNS & ":" & Mid$(szPredicate, iPos + 1)

            i = InStr(szObject, "^^")

            iPos = InStr(szObject, "#")

            ' note we cannot get here unless Object is a Literal ... !!!

            szQualifier = Mid$(szObject, i + 2, iPos - i - 1)

            '            szPrefix = szPrefix & "PREFIX q3: <" & szQualifier
& "> "

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            szObject = Mid$(szObject, 1, i - 1) & "^^" & szNS & ":" &
Mid$(szObject, (iPos + 1))

            nSubject = OIMGraph.CreateUriNode(szSubject)

            nPredicate = OIMGraph.CreateUriNode(szPredicate)

            nObject = OIMGraph.CreateLiteralNode(szObject)

            OIMGraph.Retract(New Triple(nSubject, nPredicate, nObject))

            ' the following fails ... seems execute query cannot work with
DELETE & INSERT

            '            szSPARQLDelete = szPrefix & "DELETE DATA WHERE {" &
_

            '                szSubject & " " & szPredicate & " " & szObject
& "}"

            '            aTripleStore.ExecuteQuery(szSPARQLDelete)

            i = InStr(szObject, "^^")

            szObject = szLiteral & Mid$(szObject, i) ' .substring seems to
return 1 char short

            nObject = OIMGraph.CreateLiteralNode(szObject)

            'szSPARQLInsert = szPrefix & "INSERT DATA {" & _

            '    szSubject & " " & szPredicate & " " & szObject & "}"

            OIMGraph.Assert(New Triple(nSubject, nPredicate, nObject))

Gets me much closer .... but the RDF file now has double values ....

Note an edited value ...

  <owl:Thing
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.INSIDE_DIAMETER">

    <tpl:R10528152386 rdf:resource="&part4;R34755432270" />

    <tpl:R11450580697
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R37466989245" />

    <tpl:R65789235245>100^^xsd:float</tpl:R65789235245>

    <tpl:R65789235245 rdf:datatype="&xsd;float">0</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

Unedited

  <owl:Thing
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.INSULATION_THICKNESS">

    <tpl:R10528152386 rdf:resource="&part4;R34755432270" />

    <tpl:R11450580697
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R93517282348" />

    <tpl:R65789235245 rdf:datatype="&xsd;float">0</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

If I remove the "additional" incorrect triple from the property graph ...
then

  <owl:Thing
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.ELEVATION">

    <tpl:R10528152386 rdf:resource="&part4;R82749412674" />

    <tpl:R11450580697
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R60277357355" />

    <tpl:R65789235245>1000^^xsd:float</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

This prevents my app from working (ie it no longer recognises literal
values)

Again I am just looking for a "best" practice rather than debugging my
examples

Thanks

Glen

_____________________________________________
From: Glen Worrall [mailto:gle...@bc...]
Sent: 21 November 2011 09:50
To: 'rv...@do...'
Subject: DELETE QUERY

Hi Rob,

sorry to bother you but wanted to check if the DELETE option in a SPARQL
query is working in dotNETRDF ...

I have tried various modifications etc to my file and seem to now get the
same error in my code as in the SPARQL GUI

PREFIX ex: < <http://example.org/data> http://example.org/data#>

PREFIX tpl: < <http://tpl.rdlfacade.org/data>
http://tpl.rdlfacade.org/data#>

PREFIX xmlschema: < <http://www.w3.org/2001/XMLSchema>
http://www.w3.org/2001/XMLSchema#>

DELETE 

{ex:GATE_VALVE.DGNEC__1543070000__ECXA__2.DRY_WEIGHT tpl:R65789235245
0^^xmlschema:float}

Note the prefixes have been created otherwise I received example.org is not
a valid QName exception.

Really all I want to do is update the literal in the triple store and then
write out the file ...

ie

open OWL file

display literals to user

edit literals as required

save OWL file to .OWL file

Is DELETE supported in TripleStore.ExecuteSQL(query as String) ?

I can of course send you the .OWL file I am using for testing

Thanks

Glen

Re: [dotNetRDF-Support] DELETE QUERY

[Rob V. <rv...@do...>]

Hi Glen


Re: Triple Store writers, yes some of them are designed to use multiple 
threads by default, some (but not all currently) allow you to switch them 
into single threaded mode via the IMultiThreadedWriter interface.  I've 
raised an issue in our tracker (CORE-147) to have all triple store writers 
support single threaded writing for the next release [1]


Wrt to your code example I would make the following comments:

    Iterating over the entire graph is not the best option especially as 
the graph gets larger.  You should really generate nodes for the parts of 
the triples you are trying to match and then use one of the 
GetTriplesWithXY() methods.

    For most graph implementations these lookups are indexed and so will be 
significantly faster.  If you know you are going to retract the selected 
triples you can even do something like 
g.Retract(g.GetTriplesWithXY().ToList()); Note the use of ToList() to avoid 
getting error messages about modifying a collection.
    You should compare nodes by value using the Equals() method not by 
comparing strings, the string forms of nodes are subject to collisions and 
won't properly account for the RDF rules on term equality e.g.

INode uri = g.CreateUriNode(new Uri("http://example.org"));

INode lit = g.CreateLiteralNode("http://example.org"));

Console.WriteLine(uri.ToString().Equals(lit.ToString())); //Prints true 
which is incorrect

Console.WriteLine(uri.Equals(lit)); //Prints false which is correct


Also particularly when you get into URIs there are normalization and other 
concerns, e.g. http://example.org:80 would be considered equal to 
http://example.org via Equals() but not if you do string equality they will 
not be considered equal.


As far as the RDF/XML output goes the nsXXX is the writer doing its job, if 
there is no suitable namespace defined in the graphs namespace map the 
writer must invent prefixes in order to serialize things, this has to 
follow XML namespace scoping rules so it may end up generating a ton of 
prefixes for the same namespace.  This is in part due to the fact that the 
writer is designed to be a single pass writer (as far as possible), in 
order to determine that there is a frequently used undeclared namespace 
we'd have to do an extra pass over the graph which would be very costly for 
large graphs.  You can avoid this behavior by declaring any required 
namespaces explicitly, if the graph is loaded from a file then any 
namespaces found there should be present in the resulting graph.


Regards,


Rob


[1]: http://www.dotnetrdf.org/tracker/Issues/IssueDetail.aspx?id=147 

----------------------------------------

From: "Glen Worrall" <gle...@bc...>

Sent: Tuesday, November 22, 2011 5:49 AM

To: "dotNetRDF User Help and Support" 
<dot...@li...>

Subject: Re: [dotNetRDF-Support] DELETE QUERY

Hi Rob,
FYI .... the following code is updating the graph as I expect and storing 
only a single value in the resultant RDF/XML file, i.e. working as I need 
...(although I need to now test downstream use of the file ... )
 
However .... is it efficient ?  Is it the best way ?  Note I also have to 
revisit this as it is NOT working for strings, but that may be something 
special for the strings that are being displayed as other strings have not 
been classified correctly.  I read that the nodes are immutable so I need 
to retract and assert rather than 
If aTriple.Object.NodeType = NodeType.Literal Then
      aTriple.Object.Value = szLiteral
 
Public Sub UpdateRDF(ByVal szKey As String, ByVal szProperty As String, 
ByVal szLiteral As String)
        ' v2 : update the graph
        ' OIMGraph has the graph
        ' lets try getting the triples with the szKey and szProperty
        Dim tmpGraph As New Graph
        Dim tsResults As Triple()
        Dim aTriple As Triple, tplKey As Triple, tplProperty As Triple
        Dim szSubject As String, szPredicate As String
        Dim ndSubject As VDS.RDF.UriNode
        Dim ndPredicate As VDS.RDF.UriNode
        Dim szNS As String
        Dim iPos As Integer
        szSubject = ""
        szPredicate = ""
        For Each aTriple In OIMGraph.Triples
            If aTriple.Object.ToString = szKey Then
                tplKey = aTriple
                szSubject = tplKey.Subject.ToString
                szPredicate = ""
            End If
            If aTriple.Object.ToString = szProperty Then
                If szSubject = aTriple.Subject.ToString Then
                    tplProperty = aTriple
                    szPredicate = tplProperty.Subject.ToString
                Else
                    szSubject = ""
                    szPredicate = ""
                End If
            End If
            If szSubject <> "" And szPredicate <> "" Then
                If aTriple.Object.NodeType = NodeType.Literal Then
                    OIMGraph.Retract(aTriple)
                    Dim nodNew As LiteralNode
                    nodNew = OIMGraph.CreateLiteralNode(szLiteral)
                    Dim tplNew As New Triple(aTriple.Subject, 
aTriple.Predicate, nodNew)
                    OIMGraph.Assert(tplNew)
                    ' note we have altered the collection so we have to 
exit !!
                    Exit For
                End If
                Debug.Print("<SUBJ:" & aTriple.Subject.ToString & "><PRED:" 
& aTriple.Predicate.ToString & "><OBJC:" & aTriple.Object.ToString & ">")
            End If
        Next
 
 
 
    End Sub
 
Feedback welcome ...
 
Glen
 

From: Glen Worrall [mailto:gle...@bc...] 

Sent: 22 November 2011 06:56

To: dot...@li...

Subject: Re: [dotNetRDF-Support] DELETE QUERY

 
Thanks Rob,
 
FYI the TripleStore Writers do not work with VB.NET WinForm applications
http://www.vbforums.com/showthread.php?t=552398
 
 
Therefore ... apologies ... for what is about to follow ...
 
This is meant to delete the original triple ...
            szSPARQLDelete = szPrefix & "DELETE DATA {" & _
            szSubject & " " & szPredicate & " " & szObject & "}"
            aTripleStore.ExecuteUpdate(szSPARQLDelete)
 
            i = InStr(szObject, "^^")
            szObject = szLiteral '& Mid$(szObject, i) ' .substring seems to 
return 1 char short
            'nObject = OIMGraph.CreateLiteralNode(szObject)
 
'and replace it with the new value
 
            szSPARQLInsert = szPrefix & "INSERT DATA {" & _
            szSubject & " " & szPredicate & " " & szObject & "}"
            'OIMGraph.Assert(New Triple(nSubject, nPredicate, nObject))
            aTripleStore.ExecuteUpdate(szSPARQLInsert)
            ' TripleStoreWriters all cause an issue with WinForms
            '            Dim rdfWriter As New TriGWriter
            '            aTripleStore.SaveToFile("d:\data\testing.trig", 
rdfWriter)
            '           Dim rdfWriterX As New TriXWriter
            '          aTripleStore.SaveToFile("d:\data\testing.trix", 
rdfWriter)
            '         Dim rdfWriterN As New NQuadsWriter
            '        aTripleStore.SaveToFile("d:\data\testing.trin", 
rdfWriterN)
            ' so we need to create a graph from the triplestore !!
            SaveRDF("d:\data\testing.owl", aTripleStore)
        End If
    End Sub
 
    Public Sub SaveRDF(ByVal szFilename As String, ByVal aTripleStore As 
TripleStore)
        ' aTripleStore.SaveToFile(szFilename) ha if only
        Dim rdfWriter As New RdfXmlWriter
 
        Dim sparqlparser As New SparqlQueryParser
        Dim query As SparqlQuery
        Dim results As Object
        query = sparqlparser.ParseFromString("CONSTRUCT { ?s ?p ?o } WHERE 
{?s ?p ?o}")
        results = aTripleStore.ExecuteQuery(query)
        If (results.GetType.ToString = "VDS.RDF.Graph") Then
            rdfWriter.Save(results, szFilename)
 
        End If
 
 
    End Sub
 
All runs .... but ...
note the edited triple
  <ns0:Thing 
rdf:about="http://example.org/data#GATE_VALVE.DGNEC__1543070000__ECXA__2.DRY
_WEIGHT">
    <ns63:R10528152386 xmlns:ns63="http://tpl.rdlfacade.org/data#" 
rdf:resource="http://rdl.rdlfacade.org/data#R39123699723" />
    <ns64:R11450580697 xmlns:ns64="http://tpl.rdlfacade.org/data#" 
rdf:resource="http://example.org/data#GATE_VALVE.DGNEC__1543070000__ECXA__2"
 />
    <ns65:R56806886394 xmlns:ns65="http://tpl.rdlfacade.org/data#" 
rdf:resource="http://rdl.rdlfacade.org/data#R66709707623" />
    <ns66:R65789235245 xmlns:ns66="http://tpl.rdlfacade.org/data#" 
rdf:datatype="&xsd;float">0</ns66:R65789235245>
    <rdf:type rdf:resource="http://tpl.rdlfacade.org/data#R33612674560" />
    <xsd:R65789235245 rdf:datatype="&xsd;integer">70</xsd:R65789235245>
  </ns0:Thing>
 
compared to an unedited triple
  <ns0:Thing 
rdf:about="http://example.org/data#HORIZONTAL_CENTRIFUGAL_PUMP.DGNEC__151607
0000__ECXA__2.DRY_WEIGHT">
    <ns136:R10528152386 xmlns:ns136="http://tpl.rdlfacade.org/data#" 
rdf:resource="http://rdl.rdlfacade.org/data#R39123699723" />
    <ns137:R11450580697 xmlns:ns137="http://tpl.rdlfacade.org/data#" 
rdf:resource="http://example.org/data#HORIZONTAL_CENTRIFUGAL_PUMP.DGNEC__151
6070000__ECXA__2" />
    <ns138:R56806886394 xmlns:ns138="http://tpl.rdlfacade.org/data#" 
rdf:resource="http://rdl.rdlfacade.org/data#R66709707623" />
    <ns139:R65789235245 xmlns:ns139="http://tpl.rdlfacade.org/data#" 
rdf:datatype="&xsd;float">0</ns139:R65789235245>
    <rdf:type rdf:resource="http://tpl.rdlfacade.org/data#R33612674560" />
  </ns0:Thing>
 
the original value and new value are stored ...
 
Note also the nsxxx peculiarity ...
 
Glen
 
 
 
 

From: Rob Vesse [mailto:rv...@do...] 

Sent: 21 November 2011 17:40

To: Glen Worrall

Subject: RE: DELETE QUERY

 
Hi Glen


SPARQL Query and Update are two separate standards and so the library 
handles them separately.  If you want to run updates then you need to use 
the ExecuteUpdate() method instead.  See [1] for alternative ways to apply 
updates.


If you want to create typed literals then you need to use the two argument 
version of CreateLiteralNode() which takes a URI as the second argument for 
the datatype.  Or if you have .Net primitive types you can use the 
ToLiteral() extension methods to turn these directly into literals with 
appropriate types.


SparqlGUI was designed as a query only tool, I may add update to it in the 
future but currently it does not support this.


If you have further questions please let me know,


Rob Vesse


[1]: http://www.dotnetrdf.org/content.asp?pageID=Updating%20with%20SPARQL
 

----------------------------------------

From: "Glen Worrall" <gle...@bc...>

Sent: Monday, November 21, 2011 9:13 AM

To: rv...@do...

Subject: RE: DELETE QUERY

Hi Rob,

Just to let you know I have been trying this with other options ...

        If szSubject <> "" Then

            szPrefix = ""

            ' seems that the subject. predicate, object MUST have a 
qualifier ... !!!

            iPos = InStr(szSubject, "#")

            szQualifier = Mid$(szSubject, 1, iPos)

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            'szPrefix = "PREFIX q1: <" & szQualifier & "> "

            szSubject = szNS & ":" & Mid$(szSubject, iPos + 1)

            iPos = InStr(szPredicate, "#")

            szQualifier = Mid$(szPredicate, 1, iPos)

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            'szPrefix = szPrefix & "PREFIX q2: <" & szQualifier & "> "

            szPredicate = szNS & ":" & Mid$(szPredicate, iPos + 1)

            i = InStr(szObject, "^^")

            iPos = InStr(szObject, "#")

            ' note we cannot get here unless Object is a Literal ... !!!

            szQualifier = Mid$(szObject, i + 2, iPos - i - 1)

            '            szPrefix = szPrefix & "PREFIX q3: <" & szQualifier 
& "> "

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            szObject = Mid$(szObject, 1, i - 1) & "^^" & szNS & ":" & 
Mid$(szObject, (iPos + 1))

            nSubject = OIMGraph.CreateUriNode(szSubject)

            nPredicate = OIMGraph.CreateUriNode(szPredicate)

            nObject = OIMGraph.CreateLiteralNode(szObject)

            OIMGraph.Retract(New Triple(nSubject, nPredicate, nObject))

            ' the following fails ... seems execute query cannot work with 
DELETE & INSERT

            '            szSPARQLDelete = szPrefix & "DELETE DATA WHERE {" 
& _

            '                szSubject & " " & szPredicate & " " & szObject 
& "}"

            '            aTripleStore.ExecuteQuery(szSPARQLDelete)

            i = InStr(szObject, "^^")

            szObject = szLiteral & Mid$(szObject, i) ' .substring seems to 
return 1 char short

            nObject = OIMGraph.CreateLiteralNode(szObject)

            'szSPARQLInsert = szPrefix & "INSERT DATA {" & _

            '    szSubject & " " & szPredicate & " " & szObject & "}"

            OIMGraph.Assert(New Triple(nSubject, nPredicate, nObject))

Gets me much closer .... but the RDF file now has double values ....

Note an edited value ...

  <owl:Thing 
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.INSIDE_DIAMETER">

    <tpl:R10528152386 rdf:resource="&part4;R34755432270" />

    <tpl:R11450580697 
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R37466989245" />

    <tpl:R65789235245>100^^xsd:float</tpl:R65789235245>

    <tpl:R65789235245 rdf:datatype="&xsd;float">0</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

Unedited

  <owl:Thing 
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.INSULATION_THICKNESS">



    <tpl:R10528152386 rdf:resource="&part4;R34755432270" />

    <tpl:R11450580697 
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R93517282348" />

    <tpl:R65789235245 rdf:datatype="&xsd;float">0</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

If I remove the "additional" incorrect triple from the property graph ... 
then

  <owl:Thing 
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.ELEVATION">

    <tpl:R10528152386 rdf:resource="&part4;R82749412674" />

    <tpl:R11450580697 
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R60277357355" />

    <tpl:R65789235245>1000^^xsd:float</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

This prevents my app from working (ie it no longer recognises literal 
values)

Again I am just looking for a "best" practice rather than debugging my 
examples

Thanks

Glen

_____________________________________________

From: Glen Worrall [mailto:gle...@bc...]

Sent: 21 November 2011 09:50

To: 'rv...@do...'

Subject: DELETE QUERY

Hi Rob,

sorry to bother you but wanted to check if the DELETE option in a SPARQL 
query is working in dotNETRDF ...

I have tried various modifications etc to my file and seem to now get the 
same error in my code as in the SPARQL GUI

PREFIX ex: <http://example.org/data#>

PREFIX tpl: <http://tpl.rdlfacade.org/data#>

PREFIX xmlschema: <http://www.w3.org/2001/XMLSchema#>

DELETE 

{ex:GATE_VALVE.DGNEC__1543070000__ECXA__2.DRY_WEIGHT tpl:R65789235245 
0^^xmlschema:float}

Note the prefixes have been created otherwise I received example.org is not 
a valid QName exception.

Really all I want to do is update the literal in the triple store and then 
write out the file ...

ie

open OWL file

display literals to user

edit literals as required

save OWL file to .OWL file

Is DELETE supported in TripleStore.ExecuteSQL(query as String) ?

I can of course send you the .OWL file I am using for testing

Thanks

Glen

Re: [dotNetRDF-Support] DELETE QUERY

[Glen W. <gle...@bc...>]

Hi Rob,

FYI .... the following code is updating the graph as I expect and storing
only a single value in the resultant RDF/XML file, i.e. working as I need
...(although I need to now test downstream use of the file ... )

 

However .... is it efficient ?  Is it the best way ?  Note I also have to
revisit this as it is NOT working for strings, but that may be something
special for the strings that are being displayed as other strings have not
been classified correctly.  I read that the nodes are immutable so I need to
retract and assert rather than 

If aTriple.Object.NodeType = NodeType.Literal Then

      aTriple.Object.Value = szLiteral

 

Public Sub UpdateRDF(ByVal szKey As String, ByVal szProperty As String,
ByVal szLiteral As String)

        ' v2 : update the graph

        ' OIMGraph has the graph

        ' lets try getting the triples with the szKey and szProperty

        Dim tmpGraph As New Graph

        Dim tsResults As Triple()

        Dim aTriple As Triple, tplKey As Triple, tplProperty As Triple

        Dim szSubject As String, szPredicate As String

        Dim ndSubject As VDS.RDF.UriNode

        Dim ndPredicate As VDS.RDF.UriNode

        Dim szNS As String

        Dim iPos As Integer

        szSubject = ""

       szPredicate = ""

        For Each aTriple In OIMGraph.Triples

            If aTriple.Object.ToString = szKey Then

                tplKey = aTriple

                szSubject = tplKey.Subject.ToString

                szPredicate = ""

            End If

            If aTriple.Object.ToString = szProperty Then

                If szSubject = aTriple.Subject.ToString Then

                    tplProperty = aTriple

                    szPredicate = tplProperty.Subject.ToString

                Else

                    szSubject = ""

                    szPredicate = ""

                End If

            End If

            If szSubject <> "" And szPredicate <> "" Then

                If aTriple.Object.NodeType = NodeType.Literal Then

                    OIMGraph.Retract(aTriple)

                    Dim nodNew As LiteralNode

                    nodNew = OIMGraph.CreateLiteralNode(szLiteral)

                    Dim tplNew As New Triple(aTriple.Subject,
aTriple.Predicate, nodNew)

                    OIMGraph.Assert(tplNew)

                    ' note we have altered the collection so we have to exit
!!

                    Exit For

                End If

                Debug.Print("<SUBJ:" & aTriple.Subject.ToString & "><PRED:"
& aTriple.Predicate.ToString & "><OBJC:" & aTriple.Object.ToString & ">")

            End If

        Next

 

 

 

    End Sub

 

Feedback welcome ...

 

Glen

 

From: Glen Worrall [mailto:gle...@bc...] 
Sent: 22 November 2011 06:56
To: dot...@li...
Subject: Re: [dotNetRDF-Support] DELETE QUERY

 

Thanks Rob,

 

FYI the TripleStore Writers do not work with VB.NET WinForm applications

http://www.vbforums.com/showthread.php?t=552398

 

 

Therefore ... apologies ... for what is about to follow ...

 

This is meant to delete the original triple ...

            szSPARQLDelete = szPrefix & "DELETE DATA {" & _

            szSubject & " " & szPredicate & " " & szObject & "}"

            aTripleStore.ExecuteUpdate(szSPARQLDelete)

 

            i = InStr(szObject, "^^")

            szObject = szLiteral '& Mid$(szObject, i) ' .substring seems to
return 1 char short

            'nObject = OIMGraph.CreateLiteralNode(szObject)

 

'and replace it with the new value

 

            szSPARQLInsert = szPrefix & "INSERT DATA {" & _

            szSubject & " " & szPredicate & " " & szObject & "}"

            'OIMGraph.Assert(New Triple(nSubject, nPredicate, nObject))

            aTripleStore.ExecuteUpdate(szSPARQLInsert)

            ' TripleStoreWriters all cause an issue with WinForms

            '            Dim rdfWriter As New TriGWriter

            '            aTripleStore.SaveToFile("d:\data\testing.trig",
rdfWriter)

            '           Dim rdfWriterX As New TriXWriter

            '          aTripleStore.SaveToFile("d:\data\testing.trix",
rdfWriter)

            '         Dim rdfWriterN As New NQuadsWriter

            '        aTripleStore.SaveToFile("d:\data\testing.trin",
rdfWriterN)

            ' so we need to create a graph from the triplestore !!

            SaveRDF("d:\data\testing.owl", aTripleStore)

        End If

    End Sub

 

    Public Sub SaveRDF(ByVal szFilename As String, ByVal aTripleStore As
TripleStore)

        ' aTripleStore.SaveToFile(szFilename) ha if only

        Dim rdfWriter As New RdfXmlWriter

 

        Dim sparqlparser As New SparqlQueryParser

        Dim query As SparqlQuery

        Dim results As Object

        query = sparqlparser.ParseFromString("CONSTRUCT { ?s ?p ?o } WHERE
{?s ?p ?o}")

        results = aTripleStore.ExecuteQuery(query)

        If (results.GetType.ToString = "VDS.RDF.Graph") Then

            rdfWriter.Save(results, szFilename)

 

        End If

 

 

    End Sub

 

All runs .... but ...

note the edited triple

  <ns0:Thing
rdf:about="http://example.org/data#GATE_VALVE.DGNEC__1543070000__ECXA__2.DRY
_WEIGHT">

    <ns63:R10528152386 xmlns:ns63="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R39123699723" />

    <ns64:R11450580697 xmlns:ns64="http://tpl.rdlfacade.org/data#"
rdf:resource="http://example.org/data#GATE_VALVE.DGNEC__1543070000__ECXA__2"
/>

    <ns65:R56806886394 xmlns:ns65="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R66709707623" />

    <ns66:R65789235245 xmlns:ns66="http://tpl.rdlfacade.org/data#"
rdf:datatype="&xsd;float">0</ns66:R65789235245>

    <rdf:type rdf:resource="http://tpl.rdlfacade.org/data#R33612674560" />

    <xsd:R65789235245 rdf:datatype="&xsd;integer">70</xsd:R65789235245>

  </ns0:Thing>

 

compared to an unedited triple

  <ns0:Thing
rdf:about="http://example.org/data#HORIZONTAL_CENTRIFUGAL_PUMP.DGNEC__151607
0000__ECXA__2.DRY_WEIGHT">

    <ns136:R10528152386 xmlns:ns136="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R39123699723" />

    <ns137:R11450580697 xmlns:ns137="http://tpl.rdlfacade.org/data#"
rdf:resource="http://example.org/data#HORIZONTAL_CENTRIFUGAL_PUMP.DGNEC__151
6070000__ECXA__2" />

    <ns138:R56806886394 xmlns:ns138="http://tpl.rdlfacade.org/data#"
rdf:resource="http://rdl.rdlfacade.org/data#R66709707623" />

    <ns139:R65789235245 xmlns:ns139="http://tpl.rdlfacade.org/data#"
rdf:datatype="&xsd;float">0</ns139:R65789235245>

    <rdf:type rdf:resource="http://tpl.rdlfacade.org/data#R33612674560" />

  </ns0:Thing>

 

the original value and new value are stored ...

 

Note also the nsxxx peculiarity ...

 

Glen

 

 

 

 

From: Rob Vesse [mailto:rv...@do...] 
Sent: 21 November 2011 17:40
To: Glen Worrall
Subject: RE: DELETE QUERY

 

Hi Glen

SPARQL Query and Update are two separate standards and so the library
handles them separately.  If you want to run updates then you need to use
the ExecuteUpdate() method instead.  See [1] for alternative ways to apply
updates.

If you want to create typed literals then you need to use the two argument
version of CreateLiteralNode() which takes a URI as the second argument for
the datatype.  Or if you have .Net primitive types you can use the
ToLiteral() extension methods to turn these directly into literals with
appropriate types.

SparqlGUI was designed as a query only tool, I may add update to it in the
future but currently it does not support this.

If you have further questions please let me know,

Rob Vesse

[1]: http://www.dotnetrdf.org/content.asp?pageID=Updating%20with%20SPARQL

 

  _____  

From: "Glen Worrall" <gle...@bc...>
Sent: Monday, November 21, 2011 9:13 AM
To: rv...@do...
Subject: RE: DELETE QUERY

Hi Rob,

Just to let you know I have been trying this with other options ...

        If szSubject <> "" Then

            szPrefix = ""

            ' seems that the subject. predicate, object MUST have a
qualifier ... !!!

            iPos = InStr(szSubject, "#")

            szQualifier = Mid$(szSubject, 1, iPos)

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            'szPrefix = "PREFIX q1: <" & szQualifier & "> "

            szSubject = szNS & ":" & Mid$(szSubject, iPos + 1)

            iPos = InStr(szPredicate, "#")

            szQualifier = Mid$(szPredicate, 1, iPos)

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            'szPrefix = szPrefix & "PREFIX q2: <" & szQualifier & "> "

            szPredicate = szNS & ":" & Mid$(szPredicate, iPos + 1)

            i = InStr(szObject, "^^")

            iPos = InStr(szObject, "#")

            ' note we cannot get here unless Object is a Literal ... !!!

            szQualifier = Mid$(szObject, i + 2, iPos - i - 1)

            '            szPrefix = szPrefix & "PREFIX q3: <" & szQualifier
& "> "

            szURI = New Uri(szQualifier)

            szNS = OIMGraph.NamespaceMap.GetPrefix(szURI)

            If szNS = "" Then

                szNS = "ns" & gNSCounter.ToString

                OIMGraph.NamespaceMap.AddNamespace(szNS, szURI)

                gNSCounter = gNSCounter + 1

            End If

            szObject = Mid$(szObject, 1, i - 1) & "^^" & szNS & ":" &
Mid$(szObject, (iPos + 1))

            nSubject = OIMGraph.CreateUriNode(szSubject)

            nPredicate = OIMGraph.CreateUriNode(szPredicate)

            nObject = OIMGraph.CreateLiteralNode(szObject)

            OIMGraph.Retract(New Triple(nSubject, nPredicate, nObject))

            ' the following fails ... seems execute query cannot work with
DELETE & INSERT

            '            szSPARQLDelete = szPrefix & "DELETE DATA WHERE {" &
_

            '                szSubject & " " & szPredicate & " " & szObject
& "}"

            '            aTripleStore.ExecuteQuery(szSPARQLDelete)

            i = InStr(szObject, "^^")

            szObject = szLiteral & Mid$(szObject, i) ' .substring seems to
return 1 char short

            nObject = OIMGraph.CreateLiteralNode(szObject)

            'szSPARQLInsert = szPrefix & "INSERT DATA {" & _

            '    szSubject & " " & szPredicate & " " & szObject & "}"

            OIMGraph.Assert(New Triple(nSubject, nPredicate, nObject))

Gets me much closer .... but the RDF file now has double values ....

Note an edited value ...

  <owl:Thing
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.INSIDE_DIAMETER">

    <tpl:R10528152386 rdf:resource="&part4;R34755432270" />

    <tpl:R11450580697
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R37466989245" />

    <tpl:R65789235245>100^^xsd:float</tpl:R65789235245>

    <tpl:R65789235245 rdf:datatype="&xsd;float">0</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

Unedited

  <owl:Thing
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.INSULATION_THICKNESS">

    <tpl:R10528152386 rdf:resource="&part4;R34755432270" />

    <tpl:R11450580697
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R93517282348" />

    <tpl:R65789235245 rdf:datatype="&xsd;float">0</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

If I remove the "additional" incorrect triple from the property graph ...
then

  <owl:Thing
rdf:about="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2.ELEVATION">

    <tpl:R10528152386 rdf:resource="&part4;R82749412674" />

    <tpl:R11450580697
rdf:resource="&ex;GATE_VALVE.DGNEC__1543070000__ECXA__2" />

    <tpl:R56806886394 rdf:resource="&part4;R60277357355" />

    <tpl:R65789235245>1000^^xsd:float</tpl:R65789235245>

    <type rdf:resource="&tpl;R33612674560" />

  </owl:Thing>

This prevents my app from working (ie it no longer recognises literal
values)

Again I am just looking for a "best" practice rather than debugging my
examples

Thanks

Glen

_____________________________________________
From: Glen Worrall [mailto:gle...@bc...]
Sent: 21 November 2011 09:50
To: 'rv...@do...'
Subject: DELETE QUERY

Hi Rob,

sorry to bother you but wanted to check if the DELETE option in a SPARQL
query is working in dotNETRDF ...

I have tried various modifications etc to my file and seem to now get the
same error in my code as in the SPARQL GUI

PREFIX ex: < <http://example.org/data> http://example.org/data#>

PREFIX tpl: < <http://tpl.rdlfacade.org/data>
http://tpl.rdlfacade.org/data#>

PREFIX xmlschema: < <http://www.w3.org/2001/XMLSchema>
http://www.w3.org/2001/XMLSchema#>

DELETE 

{ex:GATE_VALVE.DGNEC__1543070000__ECXA__2.DRY_WEIGHT tpl:R65789235245
0^^xmlschema:float}

Note the prefixes have been created otherwise I received example.org is not
a valid QName exception.

Really all I want to do is update the literal in the triple store and then
write out the file ...

ie

open OWL file

display literals to user

edit literals as required

save OWL file to .OWL file

Is DELETE supported in TripleStore.ExecuteSQL(query as String) ?

I can of course send you the .OWL file I am using for testing

Thanks

Glen