ORDER BY the result of UNION of subqueries

Question

I would like to compute the UNION of multiple subqueries and sort the result using ORDER BY.

So I\'d like to run this query (written in pseudo-Cypher):

Answer 1

The Cypher language does not yet support Post-Union processing.

However, as a workaround, you should be able to use the APOC procedure apoc.cypher.run to perform the UNION operation in a "subroutine", and then perform the post-UNION processing in the main Cypher query. For example:

CALL apoc.cypher.run("RETURN 2 AS x UNION RETURN 1 AS x", NULL) YIELD value
RETURN value.x AS x
ORDER BY x;

Update: this is now possible in Neo4j 4.0 using the CALL {subquery} construct.