Express abscence of edges in OpenCypher

Question

This question has an answer for how to find nodes which don't have outgoing edges on neo4j and cypher:

MATCH ()-[:A]->(n) WHERE NOT (n)-->() RETURN n

However, this does not work on Apache AGE:

select *
from cypher('graph_name', $$
    MATCH ()-[:A]->(n) WHERE NOT (n)-->() RETURN n
$$) as (n agtype)

which gives:

ERROR:  syntax error at or near ">"
LINE 3:  MATCH ()-[:A]->(n) WHERE NOT (n)-->() RETURN n
                                           ^ 

SQL state: 42601
Character: 69

How can I accomplish the same query in Apache AGE?

I'm using the latest version of Apache AGE (1.5.0) at time of posting.

I've tried variations for the NOT clause such as

• (n)-[]->()
• (n)-[r]->()
• (n)-[*]->()

but none have worked.

Answer 1

The equivalent query is:

select *
from cypher('graph_name', $$
    match ()-[:A]->(n)
    where not exists((n)-[]->())
    return distinct n
$$) as (n agtype)

The difference is that this part of the query:

WHERE NOT (n)-->()
RETURN n

is replaced with:

WHERE NOT EXISTS((n)-[]->())
RETURN DISTINCT n