Welcome to MapleDSL Documentation

Purpose

Note

It inspired by cypher-dsl, But the difference is that maple-dsl focuses more on traversal-style and lambda-style on development.

The Maple-DSL has been developed with the needs of most graph database client(e.g. neo4j, nebula-graph-java, redisgraph, etc). We wanted to avoid string concatenations in our query generation and decided do go with a builder approach, much like we find with jOOQ or in the relational module of Spring Data JDBC.

Getting Started

Prepare dependencies

CypherNebulaGraph

Inclusion of the Cypher-DSL in a Maven project

<dependency>
    <groupId>io.github.maple-dsl</groupId>
    <artifactId>maple-dsl-cypher</artifactId>
    <version>1.0.3</version>
</dependency>

Inclusion of the Nebula-DSL in a Maven project

<dependency>
    <groupId>io.github.maple-dsl</groupId>
    <artifactId>maple-dsl-nebula</artifactId>
    <version>1.0.3</version>
</dependency>

Examples

List all Tom Hanks movies released in the 1990s

constant

G.traverse(G.vertex("Person").eq("name", "Tom Hanks"))
    .outE("ACTED_IN")
    .outV("tomHanksMovies", "Movie", it -> it
        .gte("released", 1990)
        .lt("released", 2000)
        .selectAs("released", "movie_released")
        .selectAs("name", "movie_name"))
    .render()   

lambda function

@Label("Person")    Person(String name) extends Model.V
@Label("Movie")     Movie(String name, int released)  extends Model.V
@Label("ACTED_IN")  ActedIn(int type)   extends Model.E

G.traverse(G.vertex(Person.class)
    .eq(Person::getName, "Tom Hanks"))
    .outE(ActedIn.class)
    .outV("tomHanksMovies", Movie.class, it ->it
        .gte(Movie::getReleased, 1990)
        .lt(Movie::getReleased, 2000)
        .selectAs(Movie::getName, "movie_name")
        .selectAs(Movie::getReleased, "movie_released"))
    .render()

CypherNebulaGraph

MATCH (tom:`Person` {name: 'Tom Hanks'})-[:`ACTED_IN`]->(tomHanksMovies)
WHERE tomHanksMovies.released >= 1990 AND tomHanksMovies.released < 2000
RETURN tomHanksMovies.name as movie_name, tomHanksMovies.released as movie_released

LOOKUP ON `Person` WHERE Person.name == 'Tom Hanks' YIELD id(vertex) as _dst
| GO FROM $-._dst OVER ACTED_IN WHERE $$.Movie.released >= 1990 AND $$.Movie.released < 2000
YIELD $$.Movie.name as movie_name, $$.Movie.released as movie_released

via vertex ID

G.traverse("person_001")
    .outE(ActedIn.class)
    .outV("tomHanksMovies", Movie.class, it -> it
        .gte(Movie::getReleased, 1990)
        .lt(Movie::getReleased, 2000)
        .selectAs(Movie::getName, "movie_name")
        .selectAs(Movie::getReleased, "movie_released"))
    .render()

CypherNebulaGraph

MATCH (tom:`Person`)-[:`ACTED_IN`]->(tomHanksMovies)
WHERE id(tom) == 'person_001' AND tomHanksMovies.released >= 1990 AND tomHanksMovies.released < 2000
RETURN tomHanksMovies.name as movie_name, tomHanksMovies.released as movie_released

GO FROM "person_001" OVER ACTED_IN WHERE $$.Movie.released >= 1990 AND $$.Movie.released < 2000
YIELD $$.Movie.name as movie_name, $$.Movie.released as movie_released

List all Tom Hanks movies released in the 1990s, then find out the other person which acted together

G.traverse("person_001")
    .outE(ActedIn.class)
    .outV("tomHanksMovies", Movie.class, it ->it
        .gte(Movie::getReleased, 1990)
        .lt(Movie::getReleased, 2000)
        .selectAs(Movie::getName, "movie_name")
        .selectAs(Movie::getReleased, "movie_released"))
    .inE(ActedIn.class)    
    .outV("other", Person.class, it -> it
        .ne(Person::id, "person_001")
        .selectAs(Person::getName, "actor_name"))
    .render()

CypherNebulaGraph

MATCH (tom:`Person`-[:`ACTED_IN`]->(tomHanksMovies)<-[:`ACTED_IN`]-(other:`Person`)
WHERE id(tom) == 'person_001' AND tomHanksMovies.released >= 1990 AND tomHanksMovies.released < 2000 AND id(other) != 'person_001'
RETURN tomHanksMovies.name as movie_name, tomHanksMovies.released as movie_released, others.name as actor_name

GO FROM "person_001" OVER ACTED_IN WHERE $$.Movie.released >= 1990 AND $$.Movie.released < 2000
YIELD id($$) AS _dst, $$.Movie.name AS movie_name, $$.Movie.released AS movie_released
| GO FROM $-._dst OVER ACTED_IN REVERSELY WHERE id($$) != 'person_001' 
YIELD $$.Person.name AS actor_name, $-.movie_name AS movie_name, $-.movie_release AS movie_release