我有一个密码查询，我正在尝试编写等效的遍历描述，但我被顺序困住了。
start n=node:EduNodes(title='bachelor of science')
match p=n-[:JOB_CHANGE|EDUCATION|CAREER_ENTRY|EDUCATION_CONTINUED*1..4]->m
with p, relationships(p) as rels, n, m
return p,n,m,
reduce(weight=0, x in rels: weight + x.weight) as totalWeight
order by totalWeight asc
这个查询非常耗内存而且慢，遍历说明很快:
TraversalDescription td = Traversal.traversal().evaluator(Evaluators.excludeStartPosition())
.uniqueness(Uniqueness.NONE).depthFirst()
.evaluator(Evaluators.includingDepths(1, 4))
.relationships(RelationshipTypes.JOB_CHANGE, Direction.OUTGOING)
.relationships(RelationshipTypes.EDUCATION, Direction.OUTGOING)
.relationships(RelationshipTypes.CAREER_ENTRY, Direction.OUTGOING)
.relationships(RelationshipTypes.EDUCATION_CONTINUED, Direction.OUTGOING);
我可以在遍历描述中添加密码查询的最后两行(降序)吗？之后我可以自己循环完成它..
Traverser traverser = td.traverse(start);
List<PathWrapper> orderedTraversalResult = new ArrayList<>();
for (Path path : traverser) {
orderedTraversalResult.add(new PathWrapper(path));
}
Collections.sort(orderedTraversalResult);
最佳答案
您可以提供自己的能够处理分支状态的PathEvaluator。这方面最好的资源是 Neo4j 本身的单元测试，请查看 https://github.com/neo4j/neo4j/blob/master/community/kernel/src/test/java/org/neo4j/kernel/impl/traversal/TestBranchState.java .
关于java - 相当于cypher查询的遍历描述，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25761574/