如何使用Neo4j获取节点间的所有关系与路径？

Hey there! Let's tackle your two Neo4j tasks step by step—super straightforward once you know the right Cypher queries.

First off, if you're looking to pull all relationships between a specific set of nodes, start by targeting those nodes first, then match any relationships that connect them. Let's say your nodes have a label YourNodeLabel (swap this for your actual label) and you're targeting nodes with specific identifiers (like id values). Here's a sample query:

// Match all nodes in your target set
MATCH (n:YourNodeLabel)
WHERE n.id IN [1, 2, 3, 4] // Replace with your node identifiers
// Match any relationships between these nodes
MATCH (n)-[r]-(m:YourNodeLabel)
WHERE m.id IN [1, 2, 3, 4]
// Return nodes and their relationships (adjust what to return as needed)
RETURN n, r, m

Quick tips:

• If you need directed relationships (one-way connections), swap the undirected -[]- for -> or <-.
• To filter for specific relationship types, add the type inside the brackets, e.g., r:CONNECTED_TO.

For finding every path between node A and node B, Cypher's path-matching pattern is your go-to. Let's make this concrete—assuming node A has a unique property like name: 'NodeA' and node B has name: 'NodeB':

// Match all paths between A and B (no limit on path length)
MATCH p=(a:YourNodeLabel {name: 'NodeA'})-[*]-(b:YourNodeLabel {name: 'NodeB'})
// Return full paths (each path includes all nodes and relationships along the way)
RETURN p

If you want to avoid overly long paths (which can slow down queries), add a length range in the brackets—like [1..5] for paths with 1 to 5 relationships:

MATCH p=(a:YourNodeLabel {name: 'NodeA'})-[*1..5]-(b:YourNodeLabel {name: 'NodeB'})
RETURN p

For directed paths (only connections going from A to B), use -> instead of the undirected syntax:

MATCH p=(a:YourNodeLabel {name: 'NodeA'})-[*]->(b:YourNodeLabel {name: 'NodeB'})
RETURN p

No worries about the schematic—these queries work regardless of your graph's structure, just adjust labels and properties to match your actual data.

内容的提问来源于stack exchange，提问作者GT.