查询具有多个相同类型关系的节点

Question

I'm just starting to learn about Neo4J and I thought up a question I haven't seen an answer to in the reading I've been doing so far.

I believe it's possible for a Node to be connected to another Node with the same relationship multiple times.

Is it possible to return only the nodes where the number of Relationship edges meets some criteria?

Example:

Friend is a node. Poked is a relationship.

• Friend A has poked Friend B
• Friend A has poked Friend B
• Friend B has poked Friend C

How would I query this so only Friend A is selected because it has poked the same friend more than once?

If it matters; I'll be using Java and Spring's Data Graph module.

Answer 1

I'm assuming you want to use Cypher. Who wouldn't, right?

Cypher doesn't have the SQL equivalent of HAVING, so you will have to do a little bit in your host language. The query would look something like this:

START friendA=node:person(name="Michael") 
MATCH friendA-[:POKED]->friendB 
RETURN friendB, count(*)

Now, with the resulting iterable of maps, exclude from the final result all maps where count(*) is different from what you want it to be.

Does this make sense?