请求编写Neo4j Cypher查询：查找无Execution关联的首个Param节点

Got it, let's break down how to get the exact nodes you're looking for. Your goal is to find all Param nodes that are the start of a chain (so no other Param points to them via :with) and have no associated Execution node linking to them.

Here's the Cypher query that does exactly this:

MATCH (p:Param)
WHERE NOT EXISTS {
    // Check no Execution node points to this Param
    MATCH (p)<-[:with]-(:Execution)
} AND NOT EXISTS {
    // Check this Param isn't linked from another Param (so it's the first in the chain)
    MATCH (p)<-[:with]-(:Param)
}
RETURN p

Let's break down each part: #

• MATCH (p:Param): Starts by targeting all Param nodes in your graph.
• First NOT EXISTS clause: Ensures there are no Execution nodes that have a :with relationship pointing to the current Param—this filters out any Param that's connected to an Execution.
• Second NOT EXISTS clause: Makes sure the Param isn't receiving a :with relationship from another Param—this confirms it's the first node in its chain of Params.

This query will return every Param that fits both criteria: it's the start of a chain, and has no associated Execution node.

内容的提问来源于stack exchange，提问作者Fayaz