Cypher for Gremlin

Cypher for Gremlin is a toolkit for users of Apache TinkerPop™ that allows querying Gremlin databases with Cypher, the industry's most widely used property graph query language defined and maintained by the openCypher project.

The toolkit is composed of:

• translation: Cypher to Gremlin translation library for Java
• tinkerpop/cypher-gremlin-extensions: Cypher-specific custom functions and predicates for Gremlin
• tinkerpop/cypher-gremlin-server-plugin: Gremlin Server plugin that enables Cypher query processing (also includes Cypher extensions above)
• tinkerpop/cypher-gremlin-console-plugin: Gremlin Console plugin that enables client-side translation of Cypher queries or communication with a Cypher-enabled Gremlin Server
• tinkerpop/cypher-gremlin-server-client: Gremlin Server client wrapper that can send Cypher queries to a Cypher-enabled Gremlin Server
• tinkerpop/cypher-gremlin-neo4j-driver: Neo4j Java API wrapper for users familiar with Neo4j

Quick Start

The fastest way to start experimenting with Cypher for Gremlin is with the Gremlin Console Cypher plugin. Follow the link for installation and usage instructions.

You can also take a look at the Cypher for Gremlin Demo project.

Language Support

With Cypher for Gremlin you can use the following Cypher language features:

• MATCH and OPTIONAL MATCH with most of the pattern-matching syntax, except for variable-length patterns
• WHERE, ORDER BY, SKIP, and LIMIT sub-clauses
• RETURN, WITH, and UNWIND projections, including basic support for list and path comprehensions
• CREATE, MERGE, SET, REMOVE, and DETACH DELETE
• UNION operations

It is not guaranteed that all instances and combinations of the listed features will work. However, the produced translation covers around 70% of the Cypher Technology Compatibility Kit and an additional 15% on Gremlin Servers with Cypher extensions.

You are very welcome to report any issues with the translation that you encounter.

Major Limitations

• Some functionality is exclusive to Gremlin Servers with Cypher extensions, commonly provided by the Cypher Gremlin Server plugin.
• Modification of labels is not supported, because labels are immutable in Gremlin.

See the current TCK report for a detailed overview of language coverage.

Development

To build and run Cypher for Gremlin you need Java 8. The project is built using Gradle or the provided wrapper.

To build and run unit and integration tests:

./gradlew build

To automatically fix formatting errors in your changes:

./gradlew spotlessApply

How to contribute

We would love to find out about any issues you encounter and are happy to accept contributions following a Contributors License Agreement (CLA) signature as per the process outlined in our contribution guidelines.

License

The project is licensed under the Apache Software License, Version 2.0

Copyright

© Copyright 2018 Neo4j, Inc.

Apache TinkerPop™, TinkerPop, and Apache are registered trademarks of the Apache Software Foundation.