Dilemma for transitioning to Dgraph

Users Dgraph
1

Basically I have 2 hour experience with Dgraph and I am doing research if Dgraph supports a few basic use-case. Upon some research I have come to an understand that since Dgraph is distributed some operations like select * are not performance friendly.

I will be doing research and updating my post with my understanding, and here are my use cases:

Sample Graph: http://tinkerpop.apache.org/docs/3.2.9/images/tinkerpop-modern.png
Sample Graph Description:
4 people nodes and 3 software nodes with a bunch of inter-connections.

  1. Find all types of nodes/vertices in the database.
    Gremlin: g.V().label().dedup()
    NEO4J: MATCH n RETURN DISTINCT label(n)

  2. Find all nodes/vertices that belong to type “people”
    Gremlin: g.V().hasLabel(“people”)
    NEO4J: MATCH (p:people) RETURN p

  3. All the people who created a software
    Gremlin: g.V().hasLabel(“people”).out(“edge-name”)
    NEO4J: MATCH (p:people)–>(s:software) RETURN p, s

disclaimer: sample queries are for understanding purposes and might not be 100% accurate.

1 Like
2

Data Loaded:

{
  set {
    _:michael <name> "Michael" .
    _:michael <age> "39" .
    _:michael <friend> _:amit .
    _:michael <friend> _:sarah .
    _:michael <friend> _:sang .
    _:michael <friend> _:catalina .
    _:michael <friend> _:artyom .
    _:michael <owns_pet> _:rammy .

    _:amit <name> "अमित"@hi .
    _:amit <name> "অমিত"@bn .
    _:amit <name> "Amit"@en .
    _:amit <age> "35" .
    _:amit <friend> _:michael .
    _:amit <friend> _:sang .
    _:amit <friend> _:artyom .

    _:luke <name> "Luke"@en .
    _:luke <name> "Łukasz"@pl .
    _:luke <age> "77" .

    _:artyom <name> "Артём"@ru .
    _:artyom <name> "Artyom"@en .
    _:artyom <age> "35" .

    _:sarah <name> "Sarah" .
    _:sarah <age> "55" .

    _:sang <name> "상현"@ko .
    _:sang <name> "Sang Hyun"@en .
    _:sang <age> "24" .
    _:sang <friend> _:amit .
    _:sang <friend> _:catalina .
    _:sang <friend> _:hyung .
    _:sang <owns_pet> _:goldie .

    _:hyung <name> "형신"@ko .
    _:hyung <name> "Hyung Sin"@en .
    _:hyung <friend> _:sang .

    _:catalina <name> "Catalina" .
    _:catalina <age> "19" .
    _:catalina <friend> _:sang .
    _:catalina <owns_pet> _:perro .

    _:rammy <name> "Rammy the sheep" .

    _:goldie <name> "Goldie" .

    _:perro <name> "Perro" .
  }
}

Find all types of nodes:

{
  all_nodes(func: has(_predicate_)) {
    expand(_all_) {
      expand(_all_) 
    }
  }
}

This will return all the data loaded.

Find all the data that is related to particular person(Michael):

{
  expand(func: allofterms(name, "Michael")) {
    expand(_all_) {
      expand(_all_) {
        expand(_all_)
      }
    }
  }
}

I hope it is helpful for you. :slight_smile:

3

thanks I’ll take a look.

1 Like
4

if there are two type of node “Teacher” and “Student” and both have same property and value ie “name”: “Amit”, then which data will return

5

You can use @filter accordingly.

https://docs.dgraph.io/query-language/#connecting-filters
6

ok thanks will try it out