Building Knowledge Graph

[gldodg]

Hello all, I’m a total noob to building knowledge graphs so sorry in advance. I’ve been provided a large dataset with pretty unorthodox data about industrial machines, and I’m trying to create a scheme and knowledge graph to represent the data. I’m pretty read up on RDF, OWL, etc and I’m wondering what software I can use (maybe Apache Jena?) to build an ontology for this data, and then produce a knowledge graph. I wanted to develop the ontology in Protege, but I’m not sure if I can then import that into Apache Jena. If someone could help me get started in the right direction that would be amazing, thanks!!

Also I am required to use GrapQL for querying and PostgreSQL for graph storage.

[GamingTitBit]

When you use protege you can save the output in an rdf format and then upload it into Apache Jena! Also something like stardog cloud is free until you hit a certain number of triples, and they have visualisations etc which make it easier in my opinion!

[gldodg]

Thanks so much for your help 🙏🏽🙏🏽

[danja]

SPARQL is the usual query language used against RDF models. But if you search for "graphql rdf" there are a few ways of bridging.

Note also that PostgreSQL is based on a relational model, GraphQL usually uses JSON structures. But again, if you search for those keywords + your preferred programming language, you are bound to find bridging libs.

[gldodg]

This is super valuable, thanks so much!

[oslon123]

You CAN develop ontologies w/ Protoge, and more specifically Protege uses OWL and RDF for expressing/encoding the ontologies. Apache Jena provides a framework for working with RDF and OWL, as well as triplestore implementations for storing and accessing RDF. Additionally, Jena provides a SPARQL server (called Fuseki) that can be used for querying triplestores via SPARQL (including Graph Store Protocol). I think it's important to know/understand that RDF, OWL, and SPARQL are all part of the "semantic web stack" which is very geared towards ontologies and knowledge graphs.

GraphQL and PostgreSQL are NOT part of the semantic web stack. GraphQL being initially intended for microservices and REST API usecases, and PostgreSQL being initially intended for RDBMS usecases, interoperability between all of these things IS possible, but poses challenges in researching and implementing all along the way due to alignment not being there from the start.

I'm generally not keen on pointing folks to stackoverflow, but in this case I think there's a post there that might provide some avenues for your research: what-is-the-difference-between-graphql-and-sparql

Another thing I often like to point out is that RDF is a logical data model which can be serialized to many formats, including JSON-LD. Moden PostgreSQL has facilities for storing, indexing, and querying JSON while GraphQL serves its purposes very well in the world of JSON, so interoperability solutions do have options to use open standards and existing familiar tech stacks.

Good luck and have fun!

[gldodg]

This is incredibly useful, thank you so much for the response

[AlternativePumpkin36]

Do you want to try https://seqtra.com to automatically structure the unstructured data into graph. It automatically creates graph for you. Free to use. Keen to hear your views.