Hi Richard, choosing between GraphQL or DQL is basically driven by your main use case.
Dgraph can be used by application developers leveraging the flexibility of GraphQL. Dgraph will speed up the dev process and offer very good performance and scalability for the app as it automatically generates both the API and the graph backend from a GraphQL schema. If you know GraphQL, your learning curve is very short.
Dgraph can also be used by data engineers doing more sophisticated graph manipulations (pattern matching, threat detection, recommendation engine, etc …) where they need to be able to navigate a knowledge graph. DQL is the query language that will expose all the graph details. The learning curve is steeper.
If you are an app developer starts with GraphQL.
You can always use DQL even if you started with GraphQL. DQL can access all the nodes and relationships created by GraphQL approach !
We are working at making GraphQL and DQL interoperability simpler to serve the use cases where you want both a rapid app and some complex logic involving graph algorithms.
Feel free to share your use cases and what you want to achieve to have better advice from the community.