使用Tinkerpop时如何处理Neo4j ReferenceNode

Question

...在顶点和Neo4j - ReferenceNode之间创建边/关系时总是会遇到异常。

如何处理这样的事情？

GraphDatabaseService neoGraphDbService = new EmbeddedGraphDatabase( "d:/testDb" );
System.out.println(neoGraphDbService.getReferenceNode()); // Node[0]

Graph tiGraphDb = new Neo4jGraph(neoGraphDbService);

Vertex referenceNode = tiGraphDb.getVertex(0);

//throws Exception:
//org.neo4j.graphdb.NotFoundException: Node[0]
System.out.println(neoGraphDbService.getReferenceNode());

//referenceNode is null
System.out.println(referenceNode);

Vertex a = tiGraphDb.addVertex(null);
Vertex b = tiGraphDb.addVertex(null);

a.setProperty("name","marko");
b.setProperty("name","peter");

Edge referenceNode_knows_a = tiGraphDb.addEdge(null, referenceNode, a, "knows");
Edge a_knows_b = tiGraphDb.addEdge(null, a, b, "knows");

tiGraphDb.shutdown();

这是我对tinkerpop的第一次体验，我不明白referenceNode究竟发生了什么，一旦我做了tinkerpop连接，它似乎就迷失了......

顺便说一句。还没有用于tinkerpop，蓝图等的标签......

Answer 1

如果您未指定图表不是新鲜的，蓝图将删除参考节点。尝试

Graph tiGraphDb = new Neo4jGraph(neoGraphDbService, false);

防止蓝图插入图表。

/ peter