I get an error from live loader when trying to load a file and schema:
Error while processing schema file “ontology.rdf”: rpc error: code = Unknown desc = while lexing <?xml version="1.0" encoding="UTF-8"?> …
at line 1 column 5: Invalid schema: Unexpected character ’ ’ while parsing IRI
I’ve been trying to figure out how to best load Geonames.org. I’ve tried converting the Ontology to rdf http://www.geonames.org/ontology/ontology_v3.2.rdf and different kinds of json, and using as the schema for dgraph live loader. No luck so far. Just dies at things it doesn’t like, like quotes, numbers, backslashes…
Yes, but I’m not sure if this tool would convert it well. Try the Prótégé.
PS. I’ve tested with this one http://rdf-translator.appspot.com/ and it works. But you need to sanitize the data. My tip is, try to live load it and learn from the error logs output.
Thanks for the tip. I’ll try it out.
I tried just importing their data without a schema, but too many errors.
Questions:
From the docs and tutorials the schemas look pretty basic. You’re just basically saying this object gets this data type. Correct? But there’s a hierarchy to data types, eg. continent>country>state>region>city …
Is that in the schema? Or is that in the data itself?
The schema also decides what gets indexed and what doesn’t, right?
I guess what I’m trying to get at is, what parts do I cut and what parts do I keep from their rdf files?
Is the schema also in triples? Are you basically taking the objects in the schema and attaching the objects in the data?
That Prótégé app looks good. Looking forward to trying it out. Also that translator. But what output do you suggest? RDFa or N-triples?
One thing you have to pay attention to is that Dgraph does not support ontology. That is, you need to treat/sanitize this dataset before inserting it into Dgraph - and you can “simulate” ontology if you are a advanced user of GraphQL+-. There are several approaches you can take. Always remembering that Dgraph is an N-triple DB, but it is not really a triple store (as is the case with DBs that support ontology).
BTW, there is other cool tool called “OpenRefine” former “Google Refine”. You can import several formats and “refine/sanitize” it. And you can export it to JSON. In “Export => Templating”.
This tool is good to create JSON from CSV or spreadsheets too.
But you need to lear how to use the Refine queries to treat/refine/sanitize the data.
PS. You can use JSON-LD Playground to transform JSON-LD into triples. Paste the JSON-LD in the input box, and go to N-Quads tab.
Do you mean the relation? it is in the data. The edges are recorded in KV. You don’t need to define the hierarchy. It is “abstract”.
Yes, by the keyword @index(some).
Yes, that’s what I mean whit “sanitize”. As Dgraph doesn’t supports those RDFs, you should “convert” it to a supported format and remove the unnecessary parts.
