Relationship created earlier in the same query is not matched after `WITH` and `UNWIND`

[zihaozeng0021]

Describe the bug

A relationship created earlier in the same Cypher query is not matched as expected after a WITH and UNWIND pipeline.

The query creates one relationship, expands two identical lookup items with UNWIND, and attempts to match that relationship once for each input row. The resulting relationship count should be 2, but the query evaluates the condition as false and returns "FAIL".

How are you accessing AGE (Command line, driver, etc.)?

• Command line using interactive psql
• Executed through docker exec

docker exec -it test psql -U postgres -d postgres

What data setup do we need to do?

Start Apache AGE:

docker run --rm --name test -e POSTGRES_PASSWORD=agepass -p 5432:5432 apache/age:latest

Connect using interactive psql:

docker exec -it test psql -U postgres -d postgres

Load AGE, configure the search path, and create the graph:

LOAD 'age';
SET search_path = ag_catalog, public;
SELECT create_graph('test');

No separate graph data setup is required because the affected query creates the nodes and relationship itself.

What is the necessary configuration info needed?

• Docker image: apache/age:latest
• PostgreSQL: 18.1
• Apache AGE: 1.7.0
• AGE extension installed by the Docker image
• search_path set to ag_catalog, public
• Operating system: WSL2, Ubuntu 24.04.1 LTS
• Installation method: Docker

What is the command that caused the error?

SELECT *
FROM cypher('test', $cypher$
  CREATE (a:N)-[:R {id:1}]->(b:N)
  WITH [{type:'R', id:1}, {type:'R', id:1}] AS items
  UNWIND items AS item
  MATCH ()-[r:R]->()
  WHERE r.id = item.id
  RETURN CASE
    WHEN count(r) = 2 THEN 'PASS'
    ELSE 'FAIL'
  END AS value
$cypher$) AS (value agtype);

Actual result:

 value
--------
 "FAIL"
(1 row)

Expected behavior

UNWIND should produce two input rows.

For each input row, the relationship created earlier in the same query should match r.id = item.id. The resulting count(r) should therefore be 2, and the query should return:

 value
--------
 "PASS"
(1 row)

Environment (please complete the following information):

• Apache AGE version: 1.7.0
• PostgreSQL version: 18.1
• Docker image: apache/age:latest
• Operating system: WSL2, Ubuntu 24.04.1 LTS
• Access method: interactive psql through docker exec

Additional context

The behavior was reproduced twice in clean Docker containers.

[gregfelice]

The query as filed passes on current master — but it is masked rather than fixed, so I would not close this without linking it to the underlying defect.

Environment: master @ 8014174 (1.8.0), PostgreSQL 18.4, built from source. You filed against 1.7.0.

 value
--------
 "PASS"
(1 row)

Why it passes

The rule that governs this class of bug is that a reading clause sees only the rows written by the first input row of a preceding writing clause. Your CREATE (a:N)-[:R {id:1}]->(b:N) runs from a single input row, so its one edge falls inside the visible window and the later MATCH finds it.

Drive the same shape from two input rows and it still returns the wrong answer:

SELECT * FROM cypher('g', $cypher$
  UNWIND [1,2] AS i
  CREATE (a:N)-[:R {id:i}]->(b:N)
  WITH [{id:1},{id:2}] AS items
  UNWIND items AS item
  MATCH ()-[r:R]->()
  WHERE r.id = item.id
  RETURN count(r) AS matched
$cypher$) AS (matched agtype);

Correct answer is 4 — four input rows reach the MATCH, each matching exactly one edge. Actual is 2: only the edge created by the first input row (id: 1) is visible, so the two rows carrying item.id = 2 match nothing. Both edges do persist.

Underlying defect

Same root cause as #2493, where I have written it up in full along with the code references: the snapshot's curcid advances once per clause while CREATE consumes one command id per input row, so everything written by input rows 2..n stays invisible for the remainder of the statement.

Suggest tracking the fix under #2493 and keeping this issue open as the 1.7.0 report until that lands, or closing it with a pointer — whichever the maintainers prefer.