Inserting raw Python strings into named-graph

Support Bug
#1

For some reason, I cannot insert triples into a named graph that are formatted as Python strings... if the named graph contains more than 1 triple. I can insert triples into a named graph via Python strings, however, if the named graph is empty to begin with.

Not sure if I'm doing some sort of Python related thing wrong or if it's a Pystardog thing.

#2

I have not been able to reproduce this issue. Would you please provide a minimal sample of your code that can demonstrate it?

#3

Will do, let me collect something for you and share after the weekend.

#4

I can insert triples using this method if I'm creating a new named graph... if the named graph already exists, though, it will not insert any additional triples. At the moment, I can insert triples into a named graph only if I create insert a TTL file directly.

LAST_UPDATED_TRIPLE = '<{iri}> <urn:ontology:lastUpdated> "{last_updated}"^^xsd:dateTime'

def insert_stardog(triple: str, graph_iri: str):
    conn = stardog.Connection(DB_NAME, **SD_CONN_DETAILS)
    conn.begin()
    conn.add(stardog.content.Raw(triples_detail, "text/turtle"), graph_uri=graph_iri)
    conn.commit()

last_updated = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%S"))
iri = "urn:named_graph_1234"
triple = LAST_UPDATED_TRIPLE.format(iri=iri, last_updated=last_updated)
insert_stardog(triple, iri)
#5

After trying to debug this more... I have some corrections.
(1) For some reason now, inserting a single triple as a Python string works through Pystardog.
(2) Furthermore, inserting a single triple a raw file now does not work (the code above) through Pystardog.

This is how our code works currently:

def insert_stardog(triple: str, graph_iri: str):
    with stardog.Connection(DB_NAME, **SD_CONN_DETAILS) as conn:
        conn.begin()
        if file_raw == 'file':
            conn.add(stardog.content.File(triple), graph_uri=graph_iri)
        else:
            conn.add(stardog.content.Raw(triple, "text/turtle"), graph_uri=graph_iri)
        conn.commit()

I've tried creating the sample triple ('<{iri}> <urn:ontology:lastUpdated> "{last_updated}"^^xsd:dateTime') and inserting it into Stardog via Pystardog. The conn.add with the Python string now works fine... but the file will not add to the named graph no matter what I do. If I try to add it through Studio to the named graph, it works.

I'm really not sure if this a Pystardog thing or if I need to blow away my Stardog DB and build it again from scratch.

#6

What error message do you get?

I am surprised that the triple will insert without a period at the end. ie:

LAST_UPDATED_TRIPLE = '<{iri}> <urn:ontology:lastUpdated> "{last_updated}"^^xsd:dateTime .'

content.File is for inserting a file using the file name. If you try to load a file it should look something like this: conn.add(stardog.content.File('filename.ttl', 'text/turtle'). The content-type is optional. It will use 'text/turtle' if the file extension is ttl. Is it possible that you have passed a string with the file contents instead? If you do that, content.Raw should be used instead of content.File.
Link to documentation for File and Raw

#7

What error message do you get?

That's the thing... I don't get any error message back nor cause a StardogException.

I am surprised that the triple will insert without a period at the end.

Sorry, that's a copy/paste error on my part -- I did try to insert this with a period at the end.

content.File is for inserting a file using the file name. If you try to load a file it should look something like this: conn.add(stardog.content.File('filename.ttl', 'text/turtle') . The content-type is optional. It will use 'text/turtle' if the file extension is ttl . Is it possible that you have passed a string with the file contents instead? If you do that, content.Raw should be used instead of content.File .

Right, that's exactly I tried -- in the case that I was trying to add a Turtle file, my "triple" parameter would be a filename.

#8

I tried to reproduce the problem. Here is what I did.

  1. Created an empty database called test.
  2. Made a test.ttl file with this as the contents: <http://foo/abc> :testprop "xyz" .
  3. Ran this script:
import stardog

conn_details = {
  'endpoint': 'http://localhost:5820',
  'username': '...',
  'password': '...'
}

conn = stardog.Connection('test', **conn_details)

graph_uri = 'http://foo'
triple = '<http://foo/bar> :testprop "testobject" .'

conn.begin()

conn.add(
    stardog.content.Raw(triple, stardog.content_types.TURTLE),
    graph_uri=graph_uri
)

conn.add(
    stardog.content.File('test.ttl', stardog.content_types.TURTLE),
    graph_uri=graph_uri
)

conn.commit()
  1. Ran this query and my two triples are there in the named graph:
select * {
    graph <http://foo> {
        ?s ?p ?o .
    }
}

Does this simple test case work on your system? I hope this will help debug the problem.