Is there anything like a "do while" match pattern that satisfy an aggregated value ? (propeties etc)

Question

I dont know if this make sense using Cypher or graph traversal, but i was trying to do sort of a "shortest path" query but not based on weighted relationship but rather aggregated properties.

Assume i have nodes labeled People and they all vists different homepages with a VISIT relationship to the homepage node. Each homepage node has hits stats depending on its popularity. Now i would like to match people that has a visit relationship to a homepage until i reach max X number of exposure (hits).

Why ? Becuase then i know a "expected" exposure strategy for a certain group of people.

Something like

Do 
MATCH (n:People)-[:VISITS]-(sites)
while (reduce (x)<100000)

Of course this "Do while" is nothing i have seen in the Cypher syntax but wouldn't it be useful? or should this be on app level by just returning a DESC list and do the math on in the applicaton. Mabey it should also be matched with some case if the loop cant be satisfied.

MATCH (n:People)-[:VISITS]-sites
WITH reduce(hits=0, x IN collect(sites.dailyhits)| hits + x) AS totalhits
RETURN totalhits;

Can return the correct aggregated hits value (all), but i would like this function to run each matched pattern until it satisfy a value and the return the match (of course i miss other possible and mixes between pages becuase the match never traversal the entire graph..but at least i have got an answer of pages in a list that match the requirement if it makes sense) ?

Thanks!

David Makogon David Makogon · Accepted Answer · 2014-03-25T22:53:45

Not sure how you'd aggregate, but there are several aggregation functions (avg, sum, etc). And... you can pass these to a 2nd part of the cypher query, with a WITH clause.

That said: Cypher also supports the ability to sort a result (ORDER BY), and the ability to limit the number of results given (LIMIT). I don't know what you'd sort by, but... just for fun, let's sort it arbitrarily on something:

MATCH (n:People)-[v:VISITS]->(site:Site)
WHERE site.url= "http://somename.com"
RETURN n
ORDER BY v.VisitCount DESC
LIMIT 1000

This would cap your return set at 1,000 people, for people who visit a given site.

Is there anything like a "do while" match pattern that satisfy an aggregated value ? (propeties etc)

1 Answers