Search code examples
neo4jcypher

Create relationship with wildcard but only within same node type

Lets say I have 2 node types: Node1 and Node2. They both have the same property {order:Integer}

Now I want to create the relationship that nodes with order:2 have an "AFTER" relationship with nodes with order:1 BUT, I only want to create the relationships within the same node type. That is, Node1{order:2} should have an AFTER relationship to Node1{order:1} but no relationship to Node2{order:1}

When I use a wildcard, it matches and creates relationships across node types which I do not want.

MATCH (s:%{order:2}), (f:%{order:1})
CREATE (s)-[o:AFTER]->(f)

How can I achieve what I want without hard-coding each edge creation explicitly? This is what I want to avoid:

MATCH (s1:Node1{order:2}), (f1:Node1{order:1}), (s2:Node2{order:2}), (f2:Node2{order:1})
CREATE (s1)-[o:AFTER]->(f1), (s2)-[o:AFTER]->(f2)

Basically I'm trying to figure out if there's a way to have smart wildcard (I'm using SAMETYPE as a placeholder), that matches same to same. Like so:

MATCH (s:%SAMETYPE{order:2}), (f:%SAMETYPE{order:1})
CREATE (s)-[o:AFTER]->(f)
Solution

  • If each node in your database, has only one label, then this will work for you:

    MATCH (s{order:2}), (f{order:1})
WHERE labels(s)[0] = labels(f)[0]
CREATE (s)-[o:AFTER]->(f)

    In this query, we fetch all the nodes and check whether their label is same or not, and create the relationship accordingly.