Re: Conditional INSERT statements

[Andy Seaborne]

PREFIX  dri:  <http://nationalarchives.gov.uk/terms/dri#>
PREFIX  rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX  status: 
<http://nationalarchives.gov.uk/dri/catalogue/transferAssetStatus#>
PREFIX  dct:  <http://purl.org/dc/terms/>
PREFIX  xsd:  <http://www.w3.org/2001/XMLSchema#>
PREFIX  rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
DELETE {
  ?transfer dri:transferAsset ?transferAsset .
}
INSERT {
  ?transfer dri:transferAsset _:b0 .
  _:b0 dct:subject ?subject .
  _:b0 dri:transferAssetStatus status:SENT .
  _:b0 dct:modified "2013-06-13T11:58:23.468Z"^^xsd:dateTime .
}
WHERE
  { ?transfer dct:identifier "201305241200"^^xsd:string .
    ?subject dct:identifier 
"dff82497-f161-4afd-8e38-f31a8b475b43"^^xsd:string
    OPTIONAL
      { ?transfer dri:transferAsset ?transferAsset .
        ?transferAsset dct:subject ?subject .
        ?transferAsset dct:modified ?transferAssetModified
        FILTER ( ?transferAssetModified < 
"2013-06-13T11:58:23.468Z"^^xsd:dateTime )
      }
  }



Rob,

(which version of the software?)

The example data does not look like the DELETE was applied - there is 
still a dri:transferAsset link to the old state.  I would have expected 
the bnode still to be there but the triple connecting it should have gone.

If so, then the OPTIONAL is not matching -- it sets ?transferAsset.

In your example, the

    ?subject dct:identifier ...

does not match either but an INSERT does seem to have happened.

Could you delete all ?transferAsset completely?  The new state only 
depends on the new status if it's a legal state transition for the status.

To cope with the fact that COMPLETED can come before SENDING, test the 
status.


DELETE {
  ?transfer dri:transferAsset ?transferAsset .
  ?transferAsset ?p ?o .
}
INSERT {
  ?transfer dri:transferAsset _:b0 .
  _:b0 dct:subject ?subject .
  _:b0 dri:transferAssetStatus status:SENT .
  _:b0 dct:modified "2013-06-13T11:58:23.468Z"^^xsd:dateTime .
}
WHERE {
  ?transfer dct:identifier "201305241200"^^xsd:string ;
            dri:transferAssetStatus ?status ;
            dri:transferAsset ?transferAsset .
  FILTER (?status != status:COMPLETED)
  ?transferAsset ?p ?o .
} ;


SPARQL Updates can be several operations in one request.  It may be 
easier to have two operations

DELETE { ... } WHERE { ... } ;
INSERT { ... } WHERE { ... }

        Andy