如何在neo4j中获得2种不同关系的输出

时间:2015-01-27 23:28:43

标签: neo4j cypher spring-data-neo4j

我的模型是transoport系统:

节点:BusStop,Bus,TransportOperator

关系:BusStop - [:Stops_At] - >总线

关系:Bus- [Operated_By] - > TransportOperator

如果我使用以下查询,我会得到一个输出:

QUERY:

MATCH (a:BusStop{name:'Bonhoefferstrasse'}),(d:BusStop {name:'HeidelBerg Hauptbanhof'})
MATCH p = allShortestPaths((a)-[:STOPS_AT*]-(d))

RETURN EXTRACT(x IN NODES(p) | CASE WHEN x:Bus THEN 'Bus' + x.id   WHEN x:BusStop THEN 'BusStop'+ x.name
ELSE '' END) AS RouteDetails

输出:

BusStopBonhoefferstrasse, Bus34, BusStopHeidelBerg Hauptbanhof

但是从上面的关系中我是否希望运算符显示在输出中如何查询...? neo4j提供了这样做的功能吗?

例如:(这个查询错误只是为了给出并想出我想要得到的输出)

MATCH (a:BusStop{name:'Bonhoefferstrasse'}),(d:BusStop {name:'HeidelBerg Hauptbanhof'}),(e:Bus{id:''}),(f:TransportOperator{name:'Rhein-Neckar-Verkehr'})
MATCH p = allShortestPaths((a)-[:STOPS_AT*]-(d)),((e)-[:OPERATED_BY]->(f))**

RETURN EXTRACT(x IN NODES(p) | CASE WHEN x:Bus THEN 'Bus' + x.id   WHEN x:BusStop THEN 'BusStop'+ x.name WHEN x:TransportOperator THEN 'TransportOperator' ELSE '' END) AS RouteDetails

我可以加入2关系(用于上面的匹配查询)吗?

预期产出:BusStopBonhoefferstrasse,Bus34, RNV ,BusStopHeidelBerg Hauptbanhof

1 个答案:

答案 0 :(得分:2)

this answer上的扩展:

示例数据:

CREATE (a:Stop {name:'A'}),
       (b:Stop {name:'B'}),
       (c:Stop {name:'C'}),
       (d:Stop {name:'D'}),

       (a)-[:NEXT {distance:1}]->(b),
       (b)-[:NEXT {distance:2}]->(c),
       (c)-[:NEXT {distance:3}]->(d),

       (b1:Bus {id:1}),
       (b2:Bus {id:2}),
       (b3:Bus {id:3}),

       (o1:Operator {id:1}),
       (o2:Operator {id:2}),

       (b1)-[:OPERATED_BY]->(o1),
       (b2)-[:OPERATED_BY]->(o1),
       (b3)-[:OPERATED_BY]->(o2),

       (b1)-[:STOPS_AT]->(a),
       (b1)-[:STOPS_AT]->(b),
       (b2)-[:STOPS_AT]->(a),
       (b2)-[:STOPS_AT]->(b),
       (b2)-[:STOPS_AT]->(c),
       (b3)-[:STOPS_AT]->(b),
       (b3)-[:STOPS_AT]->(c),
       (b3)-[:STOPS_AT]->(d);

解决方案:

MATCH (a:Stop {name:'A'}), (d:Stop {name:'D'})
MATCH p = allShortestPaths((a)-[:STOPS_AT*]-(d))
WITH p, FILTER(x IN NODES(p) WHERE x:Bus) AS buses
UNWIND buses AS bus
MATCH (bus)-[:OPERATED_BY]->(o:Operator)
RETURN EXTRACT(x IN NODES(p) | CASE WHEN x:Stop THEN 'Stop ' + x.name
                                    WHEN x:Bus THEN 'Bus ' + x.id
                               ELSE '' END) AS itinerary,
       COLLECT('Bus ' + bus.id + ':' + 'Operator ' + o.id) AS operators

结果:

itinerary                               operators
[Stop A, Bus 2, Stop B, Bus 3, Stop D]  [Bus 2:Operator 1, Bus 3:Operator 2]
[Stop A, Bus 1, Stop B, Bus 3, Stop D]  [Bus 1:Operator 1, Bus 3:Operator 2]
[Stop A, Bus 2, Stop C, Bus 3, Stop D]  [Bus 2:Operator 1, Bus 3:Operator 2]

控制台:http://console.neo4j.org/r/p2xgiy