Dgraph: How to find two entities that are not related

Created on 23 Apr 2018 · 6Comments · Source: dgraph-io/dgraph

example：
There are 5 entities:a,b,c,d,e.
a like b
c like b
c like e
How to find the entities that not like b?

kinquestion

Source

tangzhenquan

Most helpful comment

I am assuming all entities have a name, if not you could use some other predicate for has.

{
  allEntities as var(func: has(name)) @filter(NOT eq(name, "b"))

  likeB as var(func: uid(allEntities)) @cascade {
    name
    like @filter(eq(name, "b"))
  }

  # Subtract those who like B from all entities.
  me(func: uid(allEntities)) @filter(NOT uid(likeB)) {
    name
  }
}

pawanrawal on 24 Apr 2018

👍2

All 6 comments

have you tried using @cascade ?

rebootcode on 23 Apr 2018

I am assuming all entities have a name, if not you could use some other predicate for has.

{
  allEntities as var(func: has(name)) @filter(NOT eq(name, "b"))

  likeB as var(func: uid(allEntities)) @cascade {
    name
    like @filter(eq(name, "b"))
  }

  # Subtract those who like B from all entities.
  me(func: uid(allEntities)) @filter(NOT uid(likeB)) {
    name
  }
}

pawanrawal on 24 Apr 2018

👍2

index consume so many time while putting too many data into dgraph, but function should be used in some predicates which have been indexed, i am in trouble now.