How does the WHERE clause work in the apache AGE extension inside a cypher query?

Question

This is the data setup:

select * from cypher('test', $$ CREATE (david:Person {name: 'David'})
CREATE (alice:Person {name: 'Alice'})
CREATE (bob:Person {name: 'Bob'})
CREATE (charlie:Person {name: 'Charlie'})
CREATE (eve:Person {name: 'Eve'})

CREATE (david)-[:FRIEND]->(alice)
CREATE (david)-[:FRIEND]->(bob)
CREATE (david)-[:FRIEND]->(charlie)
CREATE (david)-[:FRIEND]->(eve)
CREATE (alice)-[:FRIEND]->(bob)                                    
CREATE (charlie)-[:FRIEND]->(bob)
CREATE (eve)-[:FRIEND]->(frank:Person {name: 'Frank'})
CREATE (frank)-[:FRIEND]->(eve) 
CREATE (alice)-[:FRIEND]->(charlie) $$ ) as (a agtype);

Im searching for the query that returns the person that is a friend of David and has 2 or more outgoing relationships. According to the documantation this query should do it:

SELECT *
FROM cypher('graph_name', $$
    MATCH (david {name: 'David'})-[]-(otherPerson)-[]->()
    WITH otherPerson, count(*) AS foaf
    WHERE foaf > 1
    RETURN otherPerson.name
$$) as (name agtype);

However this returns Alice, Eve, and Charlie. It is like the WHERE clause is completely ignored. What is the correct query?

Your DB may have had existing nodes/relationships before you created the new data. Try deleting and recreating. Or, perhaps you need to use `(david:Person ...)` to be specific about the label. — cybersam, Mar 20 '23 at 18:59
there is no existing data and adding the label didnt change anything — Panagiotis Foliadis, Mar 20 '23 at 19:11
Your sample Cypher code returns only `Alice` on neo4j 4.4.9. So this might be a bug in `apache-age`. — cybersam, Mar 20 '23 at 19:15

score 2 · Accepted Answer · answered Mar 21 '23 at 04:20

This was a bug that is fixed recently (i.e WITH ignoring WHERE clause). So until now, the newest release that is v1.2.0 doesn't incorporate this fix.

If you want to make it work, pull the recent changes from github repo https://github.com/apache/age and rebuild age.

Here is what I get as output on my machine

score 0 · Answer 2 · answered Mar 20 '23 at 22:06

0

It does appear that Apache AGE is ignoring the WHERE clause inside the cypher function. One way you could do it is by using the WHERE clause outside the cypher function and adding foaf at the RETURN clause, just like this:

SELECT * FROM cypher('test', $$
    MATCH (david {name: 'David'})-[]-(otherPerson)-[]->() 
    WITH otherPerson, count(*) AS foaf 
    RETURN otherPerson.name, foaf 
    $$) as (name agtype, foaf agtype)
    WHERE foaf > 1;

This query returns every person's name that is a friend of David and has 2 or more outgoing relationships. According to the data provided it would be Alice.

answered Mar 20 '23 at 22:06

Wendel

763
1
12

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The WHERE clause is **not** being ignored, – Mohayu Din Mar 20 '23 at 23:26
how does it work then? Because everything i tested make it seem like it is being ignored – Panagiotis Foliadis Mar 20 '23 at 23:48

How does the WHERE clause work in the apache AGE extension inside a cypher query?

2 Answers2