问题描述
这类似于合并neo4j中的现有记录，删除重复项，保留关系，除了我要合并的节点具有我要保留的0-2关系.
This is similar to Merge existing records in neo4j, remove duplicates, keep relationships, except that the nodes I want to merge have 0-2 relationships I want to keep.
获取由以下人员生成的图形:
Take the graph generated by:
create (:Person {name:"Bob"})-[:RELATED_TO]->(:Person {name:"Jane"})-[:FRIENDS_WITH]->(:Person {name:"Tim"})<-[:FRIENDS_WITH]-(:Person {name:"Jane"}),
(:Person {name:"Sally"})-[:RELATED_TO]->(:Person {name:"Jane"})
我想合并重复的Jane节点，保留RELATED_TO和FRIENDS_WITH关系，删除重复项.
I want to merge the duplicate Jane nodes, preserving the RELATED_TO and FRIENDS_WITH relationships, removing the duplicates.
从另一个问题我可以得出以下结论:
From the other question I can get as far as:
match (p:Person {name:"Jane"})
with p.name as name, collect(p) as ps, count(*) as pcount
where pcount > 1
with head(ps) as first, tail(ps) as rest
unwind rest as to_delete
return to_delete
但是我似乎无法正确获得匹配项和/或可选匹配项.我尝试链接可选的匹配项并在一个语句中进行合并，而neo4j给我一个Statement.ExecutionFailure而没有其他消息.我尝试将合并合并到每个匹配项中，并以其他节点为空"结束.有想法吗?
But I can't seem to get the matches and/or optional matches correct for merging. I tried chaining optional matches and doing the merge in one statement and neo4j gives me a Statement.ExecutionFailure with no additional message. I tried breaking out the merges into each match and ended up with "other node is null". Thoughts?
推荐答案
以下查询正在运行.附带一提，对于这种重构，我很希望有一天可以设置带有动态变量的关系类型:
The following query is working. On a side note, for this kind of refactoring I would love the day when it would be possible to set a relationship type with a dynamic variable :
MATCH (n:Person { name:"Jane" })
WITH collect(n) AS janes
WITH head(janes) AS superJane, tail(janes) AS badJanes
UNWIND badJanes AS badGirl
OPTIONAL MATCH (badGirl)-[r:FRIENDS_WITH]->(other)
OPTIONAL MATCH (badGirl)<-[r2:RELATED_TO]-(other2)
DELETE r, r2, badGirl
WITH superJane, collect(other) AS friends, collect(other2) AS related
FOREACH (x IN friends | MERGE (superJane)-[:FRIENDS_WITH]->(x))
FOREACH (x IN related | MERGE (x)-[:RELATED_TO]->(superJane))
结果:
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