索引neo4j中的现有关系

Question

Is it possible to add index on existing relationships. More specifically I have a relationship called Relatadness with one property called score(score is double) and I want to index it (with java or through the web client). How can do that? thanks in advance

Answer 1

Since you already have the relationships, you'll have to iterate through all of them. This code example will create an index called RelatadnessIndex , and store the relationship in the index under a key of score :

    GlobalGraphOperations ggo = GlobalGraphOperations.at(db);
    Index<Relationship> relatadnessIndex = db.index().forRelationships("RelatadnessIndex");
    for (Relationship r : ggo.getAllRelationships()) {
        if (r.getType().name().equals("Relatadness")) {
            double score = (double) r.getProperty("score");
            relatadnessIndex.add(r, "score", score);
        }
    }

Note that by default Neo4j/Lucene will index the value as a String, so doing numeric range searches won't work. If you want to have it stored as a Numeric, you'll need to change to add to be this:

relatadnessIndex.add(r, "score", new ValueContext( score ).indexNumeric() );