使用可变长度路径时Neo4J Cypher抓取关系的类型

Question

query:

Match (d:User {name:"User"}) -[r:IS_MEMBER_OF]->(g:Group:Local) - [r1:IS_SUBGROUP_OF*0..]->(g1:Group) Return type(r), type(r1)

the cypher command type is valid for the relation without variable length paths but not valid for the variable ones even when they have the same name. How would I grab the name (type) of r1 as return from the query?

Thanks, B

Answer 1

Unfortunately, there seems to be a bug in version 2.2.1 (and maybe some earlier versions) that prevents this from working:

MATCH (:User { name:"User" })-[r:IS_MEMBER_OF]->(:Group:Local)-[r1:IS_SUBGROUP_OF*0..]->(:Group)
RETURN type(r), EXTRACT(rel IN r1 | type(rel)) AS ancestorGroupTypes;

So, this is a workaround until the above simpler query works again:

MATCH p=(:User {name:"User"})-[r:IS_MEMBER_OF]->(:Group:Local)-[r1:IS_SUBGROUP_OF*0..]->(:Group)
Return type(r), EXTRACT (rel IN TAIL(RELATIONSHIPS(p)) | type(rel)) AS ancestorGroupTypes;