Delete related triples across multiple graphs

["Cekov, Luchesar" <Lu...@nature.com>]

Hi guys,

I have a problem with specific case of sparql delete statements. I have the feeling I am doing something wrong.

My case is having a tree like graph structure starting with a certain subject and having multiple levels. The triples for different levels could be in different named graphs. I want to create a query that deletes the whole my tree. A simplified case contains only two levels.

First level in graph1

INSERT DATA {
    GRAPH <http://graph1> {
        <http://s1> <http://p1> <http:/s2>
    }
};

Second level in graph2

INSERT DATA {
    GRAPH <http:graph2> {
        <http://s2> <http://p2> "literal1" .
        <http://s2> <http://p3> <http://url1> .
    }
};

I would like to delete the triples from the second graph and any graph actually as I don't know the name of the second graph. In my real application the second graph will contain many other triples but I want to delete only the triples from the second level of my tree.
I use this delete statement:
DELETE {
    GRAPH ?g {
        <http://s1> ?p1 ?o1.
        ?o1 ?p2 ?o2.
    }
} WHERE {
    GRAPH ?g {
        <http://s1> ?p1 ?o1.
        ?o1 ?p2 ?o2.
    }
};

Unfortunately this would not work. It behaves as if deletions are not seeing triples across different graphs.

If I put all the triples in the same graph the above delete query will work. I am enclosing a junit test case that demonstrates my issue. Can anybody give a hand please? Any explanations of why this could behave like that or workarounds are very welcome.

Many thanks,
Luchesar

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Re: Delete related triples across multiple graphs

[Andy Seaborne <an...@apache.org>]

Luchesar,

 > } WHERE {
 >      GRAPH ?g {
 >          <http://s1> ?p1 ?o1.
 >          ?o1 ?p2 ?o2.
 >      }

This forces matching in one graph:

Try something like:

      GRAPH ?g1 { <http://s1> ?p1 ?o1 }
      GRAPH ?g2 { ?o1 ?p2 ?o2. }

which allows the second triple to be in a different graph.

Tip: use DELETE WHERE for when the template and the WHERE pattern are 
the same quad matching:

DELETE WHERE {
      GRAPH ?g1 { <http://s1> ?p1 ?o1 }
      GRAPH ?g2 { ?o1 ?p2 ?o2. }
}


 > I am enclosing a junit test case that demonstrates my issue.

Attachements don't get through.  Trying using a pastebin somewhere and 
sending the link.

	Andy

On 11/06/13 13:42, Cekov, Luchesar wrote:
> Hi guys,
>
> I have a problem with specific case of sparql delete statements. I have
> the feeling I am doing something wrong.
>
> My case is having a tree like graph structure starting with a certain
> subject and having multiple levels. The triples for different levels
> could be in different named graphs. I want to create a query that
> deletes the whole my tree. A simplified case contains only two levels.
>
> First level in graph1
>
> INSERT DATA {
>      GRAPH <http://graph1> {
>          <http://s1> <http://p1> <http:/s2>
>      }
> };
>
> Second level in graph2
>
> INSERT DATA {
>      GRAPH <http:graph2> {
>          <http://s2> <http://p2> "literal1" .
>          <http://s2> <http://p3> <http://url1> .
>      }
> };
>
> I would like to delete the triples from the second graph and any graph
> actually as I don't know the name of the second graph. In my real
> application the second graph will contain many other triples but I want
> to delete only the triples from the second level of my tree.
> I use this delete statement:
> DELETE {
>      GRAPH ?g {
>          <http://s1> ?p1 ?o1.
>          ?o1 ?p2 ?o2.
>      }
> } WHERE {
>      GRAPH ?g {
>          <http://s1> ?p1 ?o1.
>          ?o1 ?p2 ?o2.
>      }
> };
>
> Unfortunately this would not work. It behaves as if deletions are not
> seeing triples across different graphs.
>
> If I put all the triples in the same graph the above delete query will
> work. I am enclosing a junit test case that demonstrates my issue. Can
> anybody give a hand please? Any explanations of why this could behave
> like that or workarounds are very welcome.
>
> Many thanks,
> Luchesar
>
>
> ********************************************************************************
>
> DISCLAIMER: This e-mail is confidential and should not be used by anyone
> who is
> not the original intended recipient. If you have received this e-mail in
> error
> please inform the sender and delete it from your mailbox or any other
> storage
> mechanism. Neither Macmillan Publishers Limited nor any of its agents accept
> liability for any statements made which are clearly the sender's own and not
> expressly made on behalf of Macmillan Publishers Limited or one of its
> agents.
> Please note that neither Macmillan Publishers Limited nor any of its agents
> accept any responsibility for viruses that may be contained in this
> e-mail or
> its attachments and it is your responsibility to scan the e-mail and
> attachments (if any). No contracts may be concluded on behalf of Macmillan
> Publishers Limited or its agents by means of e-mail communication.
> Macmillan
> Publishers Limited Registered in England and Wales with registered
> number 785998
> Registered Office Brunel Road, Houndmills, Basingstoke RG21 6XS
> ********************************************************************************
>