Does Dgraph provide any means to ensure data integrity like the way we do with RDBMS - unique constraints, mandatory predicate for certain type of node, etc?
Something similar to Neo4j constraints - https://neo4j.com/docs/cypher-manual/current/schema/constraints/
In Dgraph (DQL), no. There are not any unique constrains or mandated fields. However in the GraphQL schema and API endpoint there are mechanisms for this. I’ll check out the comparison to neo4j link when I have a bit more time.
To note though, even if you setup the constraints in the GraphQL schema, you can break these constraints in DQL if you do not manually account for them using things like upserts or checking that properties exist in inputs.