Neo4j Cypher版本1.8:带有关系标识符的可能的错误

本文介绍了Neo4j Cypher版本1.8:带有关系标识符的可能的错误的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

http://console.neo4j.org/r/yx62bk

在上图中，查询

start n=node(7,8,9) 
match n-[objectScore:score]->o-[:object_of_destination]->d<-[:destination_score]-n, 
o-[:instance_of]->ot, o-[:date]->oDate, d-[:date]->dDate where ot.name='HOTEL'  
return n, o, objectScore,  d;

将o返回为空.

更改查询以删除关系标识符-objectScore

Change the query to remove relationship identifier - objectScore

start n=node(7,8,9) 
match n-[:score]->o-[:object_of_destination]->d<-[:destination_score]-n,
o-[:instance_of]->ot, o-[:date]->oDate, d-[:date]->dDate where ot.name='HOTEL'  
return n, o, objectScore,  d;

并且输出正确返回o节点.

and the output returns o node correctly.

对于我的情况，我需要两个.不知道该怎么做?对此有任何建议.

For my scenario I need both of them. Not sure How to do that? Any suggestions on this.

推荐答案

很好的发现.我们在github上跟踪Cypher的问题，所以我在那打开了一个问题: https://github .com/neo4j/community/issues/837

Nice find. We track Cypher issues on github, so I've opened an issue about it there: https://github.com/neo4j/community/issues/837

非常感谢您举报！

我发现了问题.具有讽刺意味的是，一种简单的解决方法是引入可选关系.问题出在Cypher可以使用的匹配器之一中，并且通过将一部分图案标记为可选图案，您可以强制Cypher使用其他匹配器.如果您想

I've found the problem. A simple workaround is to, ironically, introduce an optional relationship. The problem is located in one of the matchers Cypher can use, and by marking a piece of your pattern as optional, you force Cypher to use a different matcher. If you want to

因此，将您的MATCH更改为此:

So, change your MATCH to this:

match n-[objectScore:score]->o-[:object_of_destination]->d<-[:destination_score]-n, 
      o-[:instance_of]->ot, 
      o-[:date]->oDate, 
      d-[?:date]->dDate

一个真正的解决方案正在研究之中.

A real fix is in the works.

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