I just started programming in R, neo4j and R-neo4j so please be indulgent if my question is trivial.
I have created the following R Project code [2].
The database contains the outcome of computer game matches between four players. The dataset consists of four nodes, player 1 to player 4. The nodes are connected via the relationship "defeats", which indicates the outcome of the matches. There are two label entries attached to each relationship containing the following data: judge, game.
From the graph database using Cypher queries, I want to extract data in the following form (please confer the picture in [1]):
Winning player Loosing player Game Judge
player 1 player 4 Starcraft player 2
player 1 player 4 LOL player 3
player 4 player 1 LOL player 2
player 1 player 4 Starcraft player 3
player 1 player 2 LOL player 3
player 2 player 1 LOL player 4
player 4 player 1 Starcraft player 4
I want to make a query (preferred in the R-neo4j environment) to the graph database, where the input is "player 1" and the table above is returned.
I hope that my question is clear and someone can help me with this.
[2] The R (Rneo4j) code:
clear(graph)
Y
player1 = createNode(graph,"user",ID="Player 1",male=T)
player2 = createNode(graph,"user",ID="Player 2",male=T)
player3 = createNode(graph,"user",ID="Player 3",male=F)
player4 = createNode(graph,"user",ID="Player 4",male=F)
addConstraint(graph,"user","ID")
rel1 = createRel(player1,"defeats",player4)
rel2 = createRel(player1,"defeats",player4)
rel3 = createRel(player4,"defeats",player1)
rel4 = createRel(player1,"defeats",player4)
rel5 = createRel(player1,"defeats",player2)
rel6 = createRel(player2,"defeats",player1)
rel7 = createRel(player3,"defeats",player1)
rel1 = updateProp(rel1, game = "Starcraft", judge = "Player 2")
rel2 = updateProp(rel2, game = "League of Legends", judge = "Player 3")
rel3 = updateProp(rel3, game = "League of Legends", judge = "Player 2")
rel4 = updateProp(rel4, game = "Starcraft", judge = "Player 3")
rel5 = updateProp(rel5, game = "League of Legends", judge = "Player 3")
rel6 = updateProp(rel6, game = "League of Legends", judge = "Player 4")
rel7 = updateProp(rel7, game = "Starcraft", judge = "Player 4")
A couple things. If you want to use clear(graph) without having to type "Y", you can use clear(graph, input=F). Also, if you weren't aware, you can set properties on relationships when you create them:
rel1 = createRel(player1, "defeats", player4, game="Starcraft", judge="Player 2")
To answer the question, I'd do this:
getDataForPlayer = function(name) {
query = "
MATCH (winner:user)-[game:defeats]->(loser:user)
WHERE winner.ID = {name} OR loser.ID = {name}
RETURN winner.ID AS `Winning Player`,
loser.ID AS `Losing Player`,
game.game AS Game,
game.judge AS Judge
"
return(cypher(graph, query, name=name))
}
getDataForPlayer("Player 1")
Output:
Winning Player Losing Player Game Judge
1 Player 4 Player 1 League of Legends Player 2
2 Player 2 Player 1 League of Legends Player 4
3 Player 3 Player 1 Starcraft Player 4
4 Player 1 Player 2 League of Legends Player 3
5 Player 1 Player 4 Starcraft Player 2
6 Player 1 Player 4 League of Legends Player 3
7 Player 1 Player 4 Starcraft Player 3