neo4j find all nodes with matching properties

Question

I have a relatively large set of nodes, and I want to find all pairs of nodes that have matching property values, but I don\'t know or care in advance what the property valu

Answer 1

Cypher to count values on a property, returning a collection of nodes as well:

start n=node(*)
where has(n.prop)
with n.prop as prop, collect(n) as nodelist, count(*) as count
where count > 1
return prop, nodelist, count;

Example on console: http://console.neo4j.org/r/k2s7aa

You can also do an index scan with the property like so (to avoid looking at nodes that don't have this property):
start n=node:node_auto_index('prop:*') ...

2.0 Cypher with a label Label:

match (n:Label)
with n.prop as prop, collect(n) as nodelist, count(*) as count
where count > 1
return prop, nodelist, count;

Update for 3.x: has was replaced by exists.