Cypher Queries

cypher-neo4j.rb

# neo4j.rb

q = Neo4j._query("START n=node(42) RETURN n")
q.first(:n) #=> the @node
q.columns.first => :n


# neo4j.rb Cypher DSL

Neo4j.query do
 start(n=node(3,4,5))
 where(n[:name] == 'kalle')
 ret n 
end

cypher-neography.rb

# neography

@neo.execute_query("start n=node(id) return n", {:id => 3})

# batching

def batch(prepared)
  params = prepared.map { |p| [:execute_query, p[:query], p[:params]]  }
  @neo.batch(*params)
end

batch([{:query => "create n={name : {name}} return n", :params => {:name => "Foo"}},
{:query => "create n={name : {name}} return n", :params => {:name => "Bar"}},
{:query => "create n={name : {name}} return n", :params => {:name => "Foobar"}}
])

cypher.clj

; neocons
(ns neocons.docs.examples
  (:require [clojurewerkz.neocons.rest :as nr]
            [clojurewerkz.neocons.rest.nodes :as nn]
            [clojurewerkz.neocons.rest.relationships :as nrl]
            [clojurewerkz.neocons.rest.cypher :as cy]))

(defn -main
  [& args]
  (nr/connect! "http://localhost:7474/db/data/")
  (let [amy (nn/create {:username "amy" :age 27})
        bob (nn/create {:username "bob" :age 28})
        _   (nrl/create amy bob :friend {:source "college"})
        res (cy/tquery "START x = node({ids}) RETURN x.username, x.age" {:ids (map :id [amy bob])})]
    (println res)))

cypher.cs

// readify neo4jclient

return graphClient.RootNode
    .StartCypher("root")
    .Match("root-[:BELONGS]->(user)")
    .Return<SimpleResultDto>("user")
    .Results
    .OrderBy(u => u.Username);


[Test]
public void WhereBooleanOperations()
{
    // http://docs.neo4j.org/chunked/1.6/query-where.html#where-boolean-operations
    // START n=node(3, 1)
    // WHERE (n.age < 30 and n.name = "Tobias") or not(n.name = "Tobias")
    // RETURN n

    var client = Substitute.For<IGraphClient>();
    var query = new CypherFluentQuery(client)
        .Start("n", (NodeReference)3, (NodeReference)1)
        .Where<FooNode>(n => (n.Age < 30 && n.Name == "Tobias") || n.Name != "Tobias")
        .Return<object>("n")
        .Query;

    Assert.AreEqual("START n=node({p0}, {p1})\r\nWHERE (((n.Age < {p2}) AND (n.Name = {p3})) OR (n.Name != {p4}))\r\nRETURN n".Replace("'","\""), query.QueryText);
    Assert.AreEqual(3, query.QueryParameters["p0"]);
    Assert.AreEqual(1, query.QueryParameters["p1"]);
    Assert.AreEqual(30, query.QueryParameters["p2"]);
    Assert.AreEqual("Tobias", query.QueryParameters["p3"]);
    Assert.AreEqual("Tobias", query.QueryParameters["p4"]);
}

Cypher.java

ExecutionEngine engine = new ExecutionEngine(graphDB);

String query = "start n=node:Person(name={name})
 match n-[:ACTS_IN]->movie<-[:ACTS_IN]-friend
 return friend";
ExecutionResult result = engine.query(query, map("name", "Keanu");

for (Map<String,Object> row : result) {
    Node friend = row.get("friend");
}

Iterator<Node> friends = result.columnAs("friend");

for (Node friend : friends) {
    friend.getProperty("name");
}

cypher.php

// Neo4jPHP

$queryString = "START n=node({start}) ".
    "MATCH (n)<-[:KNOWS]-(x)".
    "WHERE x.name = {name}".
    "RETURN x";
$query = new Everyman\Neo4j\Cypher\Query($client, $queryString, array('start' => 1, 'name' => 'Bob'));
$result = $query->getResultSet();

CypherDSL.java

Execute q = start(node("john", john)).
            match(path().from("john").out("friend").link().out("friend").to("fof")).
            returns(properties("john.name", "fof.name"));
ExecutionResult result = engine.execute( q.toString() ).toString();


// With QueryDSL integration

class Person {
   String firstName;
   int age;
}

// QPerson generated by QueryDSL build step

QPerson person = QPerson.person;
Assert.assertEquals( "START person=node(1,2,3) WHERE person.firstName=\"P\" and person.age>25 RETURN person",
                     CypherQueryDSL.start( node( "person", 1, 2, 3 ) )
                         .where( person.firstName.eq( "P" ).and( person.age.gt( 25 ) ) )
                         .returns( nodes( "person" ) )
                         .toString() );

CypherSpringDataNeo4j.java

public interface MovieRepository extends GraphRepository<Movie> {
 @Query("start user=node:User({0}) match user-[r:RATED]->movie return movie order by r.stars desc limit 10")
 Iterable<Movie> getTopRatedMovies(User uer);
}


interface MovieRepository extends GraphRepository<Movie> {
	@Query("
	start user=node({0}) 
	match user-[:FRIEND]-friend-[r:RATED]->movie
	return movie
	order by avg(r.stars) desc, count(*) desc
	limit 10
	")
    Iterable<Movie> recommendMovies(User me);
}

@NodeEntity
public class Group {
    @Query(value = "start n=node({self}) match (n)-[r]->(friend) where r.type = {relType} return friend",
                params = {"relType", "FRIEND"})
    private Iterable<Person> friends;
}