SPARQL Subqueries and DELETE - sparql

Question

I'm trying to delete a specific triple related to a series of similar things. So, where we have...
someURI a our:thing;
our:name "literal".
someOtherURI a our:thing;
our:name "literal".
...n
I want to specifically remove all someURI our:name "literal" triples and leave the things defined.
I know I can do this via DELETE DATA, but that requires I know all URIs first, which is too many steps in itself.
I'm struggling a bit with DELETE WHERE, but I assume the answer is something like...
DELETE{ ?uri our:name ?literal }
WHERE{ ?uri a our:thing. }
Firstly, is my DELETE WHERE sound?
Secondly, I'm wondering if it's possible to nest a SELECT query within a DELETE DATA? So...
DELETE DATA{
?uri our:name ?literal
{
SELECT ?uri
WHERE {?uri a our:thing.}
}
}
Specifically, would the subquery provide the ground triple (the URI to replace the ?uri variable, or would the no variable rule for DELETE DATA throw the error first? It seems obvious, but I've been wondering and can't test it out on my triplestore. I'm using OWLIM-SE.

Answer 1

Firstly, is my DELETE WHERE sound?
Almost, but not quite. A DELETE clause can not contain any variables that are not bound in the WHERE clause (the variable ?literal, in your case). So you need to modify it slightly, like so:
DELETE {
?uri our:name ?literal .
}
WHERE {
?uri a our:thing;
our:name ?literal .
}
Secondly, I'm wondering if it's possible to nest a SELECT query within
a DELETE DATA?
That is not possible. A DELETE DATA operation can only contain fixed RDF triples - no variables and certainly no subqueries.
However, you can use a nested SELECT in a DELETE WHERE operation if you want. So the following is legal:
DELETE {
?uri our:name ?literal .
}
WHERE {
{ SELECT ?uri ?literal
WHERE { ?uri a our:thing;
our:name ?literal .
}
}
}
It doesn't really give you any advantage to do this though, in your particular case: this update expresses exactly the same thing as the first one, just in a more roundabout way.