[Neo4J] Simple cypher question

[markuse1501]

Hey everyone!

Assume there are two node entities:

public class Account extends BaseEntity
{
    ...
    @Fetch
    @RelatedTo(type = "HAS_ROLE")
    private Set<Role> roles = Sets.newHashSet();
    ...
}

public class Role extends BaseEntity
{
    ...
}

In my repository, I have a Query that gets all Accounts by a given Role:

public interface AccountRepository extends GraphRepository<Account>
{
    @Query("START account=node:Account(0) MATCH account-[:HAS_ROLE]->({0}) return account")
    Iterable<Account> findByRole(Role role);

But this query doesn't work, when I use this method in my test case I get the following error:

org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement START account=node:Account(0) MATCH account-[:HAS_ROLE]->({0}) return account; nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement START account=node:Account(0) MATCH account-[:HAS_ROLE]->({0}) return account; nested exception is expected string

As it seems, there is something wrong with my query, but I don't know what, and could't figure it out yet...
Could anyone provide some help??
THANKS!

[MichaelHunger]

this is no valid index query: node:Account(0)
if you want to find all accounts use: node:Account("key:*") where key has to be an valid, indexed key of account, or
node:`__types__`(classname="com.example.Account")

Usually what you would rather do is to lookup the role from an index (or pass it in as you already did) and just navigate from there.

i.e.

public interface AccountRepository extends GraphRepository<Account>
{
    @Query("START role=node({0}) MATCH account-[:HAS_ROLE]->role return account")
    Iterable<Account> findByRole(Role role);
}

Usually SDN can figure that out on its own (by just using a derived finder):

public interface AccountRepository extends GraphRepository<Account>
{
    Iterable<Account> findByRoles(Role role);
}

[markuse1501]

Hey Michael!
Many thanks, the lookup from the role index works perfect.
Using a derived query didn't work, it always ended in:

java.lang.IllegalStateException: Error roles SIMPLE_PROPERTY points neither to a primitive nor a entity property of class de.bht.streetartatlas.domain.auth.Account unmanaged @NodeEntity Annotations: [interface org.springframework.data.neo4j.annotation.NodeEntity]

A lot of new things to learn...

[MichaelHunger]

Thanks Markus,

Could you perhaps create a small test/sample project that exhibits the problem in a test?

That would help me to easily pinpoint and fix it.

Thanks

Michael

[markuse1501]

Hey Michael,

here's my project...
It's simple, so far...

The problem:
This works fine, thanks to you:

@Query("START role=node({0}) MATCH account-[:HAS_ROLE]->role return account")
Iterable<Account> findByRoles(Role role);

Without the query string, the error occurs:

Error roles SIMPLE_PROPERTY points neither to a primitive nor a entity property of class de.bht.streetartatlas.domain.auth.Account unmanaged @NodeEntity Annotations: [interface org.springframework.data.neo4j.annotation.NodeEntity]

P.S.: The relevant one is AccountServiceTest...

[MichaelHunger]

Thanks for pointing it out, will fix it, see

https://jira.springsource.org/browse/DATAGRAPH-308