Cypher中路径的零个或多个

Question

For example I have a path:

1-[:A]->2-[:B]->3

And we can use the * operator to define if a particular edge can be repeated. I would like to use the * operator on the entire path, or both edges combined. I would like to follow: (A AND B) zero or more times.

Example:

1-[:A]->2-[:B]->3-[:A]->4-[:B]->5...

I am not sure how to apply the * operator for the entire path in Cypher. My intent is to express a pattern that allows a specific path to be repeated 0 or more times.

Answer 1

This is something variable-length patterns cannot do in Cypher. However, because of this, we added repeating sequences functionality to path expander procs in APOC Procedures .

As an example:

MATCH (n)
WHERE id(n) = 123
CALL apoc.path.expandConfig(n, {relationshipFilter:'A>, B>'}) YIELD path
RETURN path

This expands from a start node ( n ) expanding out only a repeating sequence of outgoing :A and :B relationships. No minLevel or maxLevel properties were provided, so this has a minimum of 0 length and no bounds on max length.