Don't resolve circular possible circular relationships for queries returning count or exists projections.

[martin-salinger]

Hi,

with version 6.0.4 and 6.0.5 a derived count query like
long countByLastname(String lastname);
throws an AopInvocationException:
org.springframework.aop.AopInvocationException: Null return value from advice does not match primitive return type

The reason is an incorrectly generated cypher query:
MATCH ... WITH collect(id(n)) AS __sn__ RETURN __sn__

With version 6.0.3 (and before) the cypher query is generated correctly:
MATCH ... RETURN count(*)

BTW: Thanks a lot for the great work!

[michael-simons]

I can confirm this bug.

[michael-simons]

This will be fixed in the next patch.

We are sorry for causing you issues. The root cause is to be related in the much improved querying of cycling mapping, which get's triggered by your mapping.

To mitigate the issue, you can use

@Query(value = "MATCH (n:Label {lastname: $lastname}) RETURN count(n)", count = true)
long countByLastname(String lastname);

or

@Query(value = "MATCH (n:Label {lastname: $lastname}) RETURN count(n) > 0", exists = true)
long existByLastname(String lastname);

(exists being affected as well).

[martin-salinger]

Thank you for the custom query to mitigate the issue!

It´s good to hear that the querying of cycling mapping has been much improved 👍