Question

使用Cypher，通过以逗号分隔它们来选择多个节点：

START n=node(1, 2, 3) RETURN n

http://docs.neo4j.org/chunked/milestone/query-start.html#start-multiple-nodes-by-id

我想在Spring Data @Query中使用它，但它不起作用：

@Query("start person=node({0}) match (person)-[:has_friends]->(friend) return friend")
private Iterable<Person> friends(Iterable<Person> persons);

修改这是堆栈跟踪：

java.lang.ClassCastException: Person cannot be cast to org.neo4j.graphdb.Node
  at org.neo4j.kernel.impl.traversal.AsOneStartBranch.toBranches(AsOneStartBranch.java:65)
  at org.neo4j.kernel.impl.traversal.AsOneStartBranch.<init>(AsOneStartBranch.java:59)
  at org.neo4j.kernel.impl.traversal.BidirectionalTraverserIterator.<init>(BidirectionalTraverserIterator.java:81)
  at org.neo4j.kernel.impl.traversal.BidirectionalTraverserImpl.instantiateIterator(BidirectionalTraverserImpl.java:44)
  at org.neo4j.kernel.impl.traversal.AbstractTraverser.iterator(AbstractTraverser.java:83)
  at org.neo4j.cypher.internal.pipes.matching.BidirectionalTraversalMatcher.findMatchingPaths(BidirectionalTraversalMatcher.scala:73)
  at org.neo4j.cypher.internal.pipes.TraversalMatchPipe$$anonfun$createResults$1.apply(TraversalMatchPipe.scala:32)
  at org.neo4j.cypher.internal.pipes.TraversalMatchPipe$$anonfun$createResults$1.apply(TraversalMatchPipe.scala:29)
  at scala.collection.Iterator$$anon$21.hasNext(Iterator.scala:371)
  at scala.collection.Iterator$$anon$21.hasNext(Iterator.scala:371)
  at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
  at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
  at org.neo4j.cypher.PipeExecutionResult.hasNext(PipeExecutionResult.scala:138)
  at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
  at scala.collection.JavaConversions$IteratorWrapper.hasNext(JavaConversions.scala:562)
  at org.neo4j.helpers.collection.IteratorWrapper.hasNext(IteratorWrapper.java:42)

有什么想法吗？

Answer 1

您应该从node(*)而不是node(0)开始。

Answer 2

我认为Person注明了@NodeEntitiy。正如堆栈跟踪所述，Node（s）（ NodeId（s）（Long），也可以工作，如果你想用它代替{{ 1}}在{0}

中

Answer 3

在当前版本的SDN中，此查询应该有效：

@Query("(person)-[:has_friends]->(friend) where id(person) IN {0} return friend")
private Iterable<Person> friends(Iterable<Person> persons);

使用Spring Data Neo4j @Query选择多个节点

3 个答案: