Cypher - Limit Number of Nodes created by a Single Author

Neo4j Graph Platform Cypher
1

I have a database of multiple pieces of content all of which have an author relationship.

I want to be able to write a query that returns "recent" content (say 20 posts) but I don't want posts by the same author to appear more than 3 times in the results.

Is there a way to do this in Cypher?

2

Hello and Welcome to the Neo4j Community!

Not sure how you define recent, but to return at most 3 posts per author:

MATCH (p:Person)-[:POSTED]->(c:Content
WITH p, collect(c.subject) as theContent
WHERE size(theContent) <= 3
RETURN p.name, theContent

To get the most recent content, you would place an ORDER BY clause in the WITH clause to order them.

Elaine

3

Thank you very much.

In my case it will be in descending order of creation date (the nodes will have a creation date property). But only a max of 3 posts created by the same author appearing in the results. For a max of 20 (or whatever limit we set)

4

Try this:

MATCH (p:Person)-[:POSTED]->(c:Content)
WITH p, c ORDER by c.datePosted DESC
WITH p, collect(c.subject) as theContent
WHERE size(theContent) <= 3
RETURN p.name, theContent

5

Note that the suggested query is a filtering query, so it will only find authors that created 3 posts or less.

If you want to include those authors but limit the content, you need a way to limit results per row.

We have a knowledge base article with a few different ways to perform this:

So for example you can take the relevant slice of each collection:

MATCH (p:Person)-[:POSTED]->(c:Content)
WITH p, c ORDER by c.datePosted DESC
WITH p, collect(c.subject)[..3] as theContent
RETURN p.name, theContent