CODEWITHSUNDEEP
gremlinamazon-neptune
Aditya
Aditya

Reputation: 25

Find common recommendations in neptune db using gremlin queries

I have to find only common friends for two or more users in a way that both of them have same friend. g.V().has('users','id', within('A', 'B')).out('friend_with').values() This query will give back all friends that are associated with A or B. However, how can I get friends that are associated with A & B.

g.V().has('users','id', within('A', 'B')).out('friend_with').values()

Upvotes: 1

Views: 63

Answers (1)

Kelvin Lawrence
Kelvin Lawrence

Reputation: 14371

One way to do this is to groupCount the results and only keep the ones where the count is 2. That means you will have got there from both A and B (assuming there are no duplicate edges between friends). This will look something like:

g.V().has('users','id', within('A', 'B')).
  out('friend_with').
  groupCount()

To then filter out anything that does not have a value of 2

g.V().has('users','id', within('A', 'B')).
  out('friend_with').
  groupCount().
  unfold().
  where(select(values).is(2))

and to get the values from the ones left

g.V().has('users','id', within('A', 'B')).
  out('friend_with').
  groupCount().
  unfold().
  where(select(values).is(2)).
  select(keys).
  values()

Upvotes: 0

Related Questions