Neo4j : Passing Relationship as a query parameter

Question

I have created the following query which works fine when i am passing all the relationship.

@Query(value="START profile=node(*) "
                + "MATCH profile - [rel:create | stream | like | follow] - feeds "
                + "WHERE profile.id ={profileId} "
                + "WITH distinct feeds as feed, rel.date as date "
                + "ORDER BY date DESC "
                + "RETURN DISTINCT feed;")
    public List<Feed> findByProfileId(@Param("profileId") String profileId);

but i want to fetch data for specific action like the query below

@Query(value="START profile=node(*) "
                + "MATCH profile - [rel:{action}] - feeds "
                + "WHERE profile.id ={profileId} "
                + "WITH distinct feeds as feed, rel.date as date "
                + "ORDER BY date DESC "
                + "RETURN DISTINCT feed;")
public List<Feed> findByProfileId(@Param("action") String action,@Param("profileId") String profileId);

But this does not work and i get the following error.

org.neo4j.rest.graphdb.RestResult Exception: Invalid input '{': expected whitespace or an identifier

I think this is not a correct way to pass param in relationship. Is there a way how i can achieve this.

Answer 1

1. you should not use start n=node(*) in your query use a label like :Profile and an index/unique constraint on :Profile(id)

   MATCH (profile:Profile) WHERE profile.id = {profileId}

2. you can't use rel-types as parameters directly but you can check the type of your relationship, eg against a set of names that is passed in

either

WHERE type(rel) = {action}

or

WHERE type(rel) IN {actions}

Answer 2

There is no way currently to pass relationship types nor labels as query parameters.

You will need to handle it in your application, when building the query string.

Here is a simple example in PHP :

$relTypes = array(':FACEBOOK_PROFILE',':TWITTER_PROFILE');
$relString = implode('|', $relTypes);
$q = 'MATCH (n:User)-['.$relString.']->(profile)';