cypher subquery: get node with max/min value and process it

Question

I struggle to return the node with the largest value, and process that node further.

Here's how I would return a node with the largest value:

START n=node(startnode)
MATCH n-[:TYPE]-m
RETURN m
ORDER BY m.value DESC LIMIT 1

but now I am in a subquery

START n=node(somenode)
MATCH n-[:TYPE1]-q
WITH DISTINCT q
MATCH q-[:TYPE2]-m

and then the ORDER BY .. LIMIT 1 obviously doesn't work anymore because I want one result for each q. How is this done?

Also, once I have the m with largest value for each q I'll also need to process it:

RETURN q, m.maxvalue, x.anothervalue

from

MATCH m-[:HAS_ONE_LINK_TO]->x

So while I've been playing with collections (collect(m) ), I haven't figured a way to expand them back to "result rows" for applying that MATCH.

Answer 1

Untested... let me know if it works for you:

START n=node(somenode)
MATCH n-[:TYPE1]-q                // initial query
WITH DISTINCT q
MATCH q-[:TYPE2]-m
WITH q, max(m.value) as max       // get max for q
MATCH q-[:TYPE2]-m                
WHERE m.value = max               // find the max m for each q
WITH q, m
MATCH m-[:HAS_ONE_LINK_TO]->x     // find x from m
RETURN q, m, x

Edit: because of recent upvotes on this old answer... please consider a fresher query written in 3.x era using collect/unwind -- also untested (take care to not do this if the number of ms will be quite large, as they may be stored in the partial result of the query instead of being able to stream them):

MATCH (n:Label)-[:TYPE1]-(q)                  // initial query
WITH DISTINCT q
MATCH (q)-[:TYPE2]-(m)
WITH q, max(m.value) as max, collect(m) as ms // get max for q, collect ms
UNWIND ms as m
WHERE m.value = max
MATCH (m)-[:HAS_ONE_LINK_TO]->(x)             // find x from m
RETURN q, m, x