从两个命名图插入？

Question

I'm looking for an easy way to insert triples from two or more named graphs (but not the entire unnamed default graph) into another named graph. I'm using GraphDB.

I guess this could be done by writing out the same query multiple times in the WHERE section, wrapped in multiple GRAPH specifications, and then unioning them together, but my WHERE s are long and I'd prefer not to write them out multiple times.

Let's say I have loaded some data like this:

INSERT DATA {
  GRAPH <http://example.com/ngA> {
    <http://example.com/person1> <http://example.com/name> "Arthur" .
  }
  GRAPH <http://example.com/ngB> {
    <http://example.com/person1> <http://example.com/name> "Brian" .
  }
  GRAPH <http://example.com/ngC> {
    <http://example.com/person1> <http://example.com/name> "Charlie" .
  }
}

I can copy all of the triples of a certain pattern from the default unnamed graph into a new named graph with something like this:

INSERT {
  GRAPH <http://example.com/ngZ> {
    ?s <http://example.com/moniker> ?o .
  }
}
WHERE
  { ?s  <http://example.com/name>  ?o }

An easy way to SELECT for triples of a given pattern from two or more (but not all) named graphs is

SELECT  *
FROM <http://example.com/ngA>
FROM <http://example.com/ngB>
WHERE
  { ?s  <http://example.com/name>  ?o }

What if I want to copy those triples, from those specified graphs, into another graph?

I'm getting an error from GraphDB 8.3 (and from the sparql.org validator) when I try to

INSERT {
  GRAPH <http://example.com/ngZ> {
    ?s <http://example.com/moniker> ?o .
  }
}
WHERE
  { SELECT  *
FROM <http://example.com/ngA>
FROM <http://example.com/ngB>
WHERE
  { ?s  <http://example.com/name>  ?o } }

Answer 1

Thanks, @Stanislav Kralin

Come to think of it, this also works:

PREFIX ex: <http://example.com/>
INSERT {
    GRAPH ex:ngZ {
        ?s ex:moniker ?o 
    }
}
WHERE {
    values ?g {
        ex:ngA ex:ngB 
    }
    GRAPH ?g {
        ?s ex:name ?o 
    }  
}

Answer 2

Try this query:

PREFIX ex: <http://example.com/>

INSERT {
  GRAPH ex:ngZ { ?s ex:moniker ?o }
}
WHERE {
  GRAPH ?g { ?s ex:name ?o }  
  FILTER (?g IN ( ex:ngA, ex:ngB ) )
}

And then:

PREFIX ex: <http://example.com/>

SELECT * 
FROM NAMED ex:ngZ
WHERE { 
    GRAPH ?g { ?s ?p ?o }
} LIMIT 100 

Is it what you need?

By the way, there exist COPY (use with caution!) and ADD .

Answer 3

SPARQL Update provides USING and USING NAMED analogous to FROM and FROM NAMED in queries:

The USING and USING NAMED clauses affect the RDF Dataset used while evaluating the WHERE clause. This describes a dataset in the same way as FROM and FROM NAMED clauses

You can express the requirement as an UPDATE like so:

INSERT {
  GRAPH <http://example.com/ngZ> {
    ?s <http://example.com/moniker> ?o .
  }
}
USING <http://example.com/ngA>
USING <http://example.com/ngB>
WHERE
  {  ?s  <http://example.com/name>  ?o }

Also note that, according to the SPARQL query grammar , a subquery does not admit a dataset clause. This is why the SPARQL parsers are rejecting your query.