Neo4j Cypher Query Builder

Question

I have been trying to come across a query builder for Neo4j's query language Cypher, ideally using a fluent API. I did not find much, and decided to invest some time on building one myself.

The result so far is a fluent API query builder for the Cypher 1.9 spec.

I wanted to use StackOverflow to kick off a discussion and see what the thoughts are, before I release the code.

Here is a demo query that you would want to send off to Neo4j using Cypher.

Show me all people who John knows who know software engineers at Google (Google company code assumed to be 12345). The relationship strength between John and the people who connect him to Google employees should be at least 3 (assuming a range from 1-5). Return all of John's connections and the people they know at Google, including the relationships between those people. Sort the results by name of John's connections in ascending order and then by relationship strength in descending order.

Using Fluent-Cypher:

Cypher
    .on(Node.named("john").with(Index.named("PERSON_NAMES").match(Key.named("name").is("John"))))
    .on(Node.named("google").with(Id.is(12345)))

    .match(Connection.named("rel1").andType("KNOWS").between("john").and("middle"))
    .match(Connection.named("rel2").andType("KNOWS").between("middle").and("googleEmployee"))
    .match(Connection.withType("WORKS_AT").from("googleEmployee").to("google"))

    .where(Are.allOfTheseTrue(Column.named("rel1.STRENGTH").isGreaterThanOrEqualTo(3)
            .and(Column.named("googleEmployee.TITLE").isEqualTo("Software Engineer"))))

    .returns(Columns.named("rel1", "middle", "rel2", "googleEmployee"))
    .orderBy(Asc.column("middle.NAME"), Desc.column("rel1.STRENGTH"))

which yields the following query:

START john=node:PERSON_NAMES(name='John'),google=node(12345) MATCH john-[rel1:KNOWS]-middle,middle-[rel2:KNOWS]-googleEmployee,googleEmployee-[:WORKS_AT]->google WHERE ((rel1.STRENGTH >= '3' AND googleEmployee.TITLE = 'Software Engineer')) RETURN rel1,middle,rel2,googleEmployee ORDER BY middle.NAME ASC,rel1.STRENGTH DESC

Answer 1

I agree that you should build this with an eye towards Cypher 2.0. As of 2.0, it's very important that WHERE clauses are matched up with the correct START, (OPTIONAL) MATCH, and WITH clauses making the design of a fluent API a bit more challenging.