Graph DB: Sort product based on likes

问题

I have a product vertex which has incomming like edge.

    User ------- likes ----------->products

In my search result I want to sort the products based on likes. How this can be done ?

回答1:

Just use groupCount:

gremlin> g = new TinkerGraph()
==>tinkergraph[vertices:0 edges:0]
gremlin> user1 = g.addVertex('u1')
==>v[u1]
gremlin> user2 = g.addVertex('u2')
==>v[u2]
gremlin> product1 = g.addVertex('p1')
==>v[p1]
gremlin> product2 = g.addVertex('p2')
==>v[p2]
gremlin> product3 = g.addVertex('p3')
==>v[p3]
gremlin> user1.addEdge('like',product1)  
==>e[0][u1-like->p1]
gremlin> user1.addEdge('like',product2)
==>e[1][u1-like->p2]
gremlin> user2.addEdge('like',product2)
==>e[2][u2-like->p2]
gremlin> user2.addEdge('like',product3)
==>e[3][u2-like->p3]
gremlin> g.v('u1','u2').out('like').groupCount().sort{-it.value}
Cannot invoke method negative() on null object
Display stack trace? [yN] n
gremlin> g.v('u1','u2').out('like').groupCount().cap.next().sort{-it.value}
==>v[p2]=2
==>v[p1]=1
==>v[p3]=1

来源：https://stackoverflow.com/questions/24583548/graph-db-sort-product-based-on-likes