Neo4J在Cypher中创建临时变量 [英] Neo4J create temp variable within Cypher
问题描述
所以我的首要问题是我试图返回MERGE
是否导致创建新节点.
So my Top-Level problem is I am trying to return whether a MERGE
resulted in the creation of a new Node or not.
为了做到这一点,我想我可以创建一个简单的临时布尔值,使用ON CREATE
In order to do this I was thinking I could just create a simple temp boolean setting it to TRUE using ON CREATE
我如何想象它的工作原理:
How I imagine it working:
MERGE(: Person {id:'Tom Jones'})
WITH false as temp_bool
ON CREATE set temp_bool = true
RETURN temp_bool
显然这是行不通的.
我正在寻找一种在Cypher查询中创建任意临时值的方法,并能够最终返回这些变量.
I am looking for a way to create arbitrary temp values within a Cypher query, and have the ability to return those variables in the end.
谢谢
推荐答案
您可以按照自己的方式做(我的第一个答案加上@cybersam的结合).只需使用您创建并删除的节点属性来完成它,而不是像您一直尝试的那样使用未绑定的变量.
You can do what you want, here's how (combination of my first answer, with @cybersam's addition). You just do it with a node property you create and then remove, instead of an unbound variable as you've been trying.
MERGE(tom:Person {id:'Tom Jones'})
ON CREATE set tom.temp_bool = true
ON MATCH set tom.temp_bool = false
WITH tom, tom.temp_bool AS result
REMOVE tom.temp_bool
RETURN result;
这篇关于Neo4J在Cypher中创建临时变量的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!