Cypher query with literal map syntax & dynamic keys

Question

I'd like to make a cypher query that generates a specific json output. Part of this output includes an object with a dynamic amount of keys relative to the children of a parent node:

{
   ...

   "parent_keystring"                 : {
           child_node_one.name        : child_node_one.foo
           child_node_two.name        : child_node_two.foo       
           child_node_three.name      : child_node_three.foo
           child_node_four.name       : child_node_four.foo
           child_node_five.name       : child_node_five.foo
   }
}

I've tried to create a cypher query but I do not believe I am close to achieving the desired output mentioned above:

MATCH (n)-[relone:SPECIFIC_RELATIONSHIP]->(child_node)
WHERE n.id='839930493049039430'
RETURN n.id          AS id,
       n.name        AS name,
       labels(n)[0]  AS type,
       {
           COLLECT({ 
              child.name : children.foo
           }) AS rel_two_representation
       } AS parent_keystring

I had planned for children.foo to be a count of how many occurrences of each particular relationship/child of the parent. Is there a way to make use of the reduce function? Where a report would generate based on analyzing the array proposed below? ie report would be a json object where each key is a distinct RELATIONSHIP and the property value would be the amount of times that relationship stems from the parent node?

Thank you greatly in advance for guidance you can offer.

dynamic keys don't work yet, I think there might be some plans to add them in the future — Michael Hunger
Since then, user-defined procedures (APOC) support this, see this answer: stackoverflow.com/a/41907779/3580502 — Gabor Szarnyas

Brian Underwood Brian Underwood · Accepted Answer · 2015-09-17T05:03:23

I'm not sure that Cypher will let you use a variable to determine an object's key. Would using an Array work for you?

COLLECT([child.name, children.foo]) AS rel_two_representation

Cypher query with literal map syntax & dynamic keys

2 Answers