Neo4J：好友推荐简单示例

CREATE (leBig:Dude {name: "Lebowski"})
CREATE (dudeA1:Dude {name: "A1"})
CREATE (dudeA2:Dude {name: "A2"})

CREATE (leBig)<-[:FRIEND_OF]-(dudeA1)
CREATE (leBig)<-[:FRIEND_OF]-(dudeA2)

CREATE (dudeB1:Dude {name: "B1"})
CREATE (dudeB2:Dude {name: "B2"})
CREATE (dudeB3:Dude {name: "B3"})

MATCH (dudeA1:Dude {name: "A1"})
MATCH (dudeA2:Dude {name: "A2"})
MATCH (dudeB1:Dude {name: "B1"})
MATCH (dudeB2:Dude {name: "B2"})
MATCH (dudeB3:Dude {name: "B3"})
CREATE (dudeA1)<-[:FRIEND_OF]-(dudeB1)
CREATE (dudeA1)<-[:FRIEND_OF]-(dudeB2)
CREATE (dudeA1)<-[:FRIEND_OF]-(dudeB3)
CREATE (dudeA2)<-[:FRIEND_OF]-(dudeB1)
CREATE (dudeA2)<-[:FRIEND_OF]-(dudeB2)
CREATE (dudeA2)<-[:FRIEND_OF]-(dudeB3)

CREATE (dudeC1:Dude {name: "C1"})
CREATE (dudeC2:Dude {name: "C2"})
CREATE (dudeC3:Dude {name: "C3"})
CREATE (dudeC4:Dude {name: "C4"})

CREATE (dudeB1)<-[:FRIEND_OF]-(dudeC1)
CREATE (dudeB1)<-[:FRIEND_OF]-(dudeC2)
CREATE (dudeB1)<-[:FRIEND_OF]-(dudeC3)
CREATE (dudeB1)<-[:FRIEND_OF]-(dudeC4)

CREATE (dudeB2)<-[:FRIEND_OF]-(dudeC1)
CREATE (dudeB2)<-[:FRIEND_OF]-(dudeC2)
CREATE (dudeB2)<-[:FRIEND_OF]-(dudeC3)
CREATE (dudeB2)<-[:FRIEND_OF]-(dudeC4)

CREATE (dudeB3)<-[:FRIEND_OF]-(dudeC1)
CREATE (dudeB3)<-[:FRIEND_OF]-(dudeC2)
CREATE (dudeB3)<-[:FRIEND_OF]-(dudeC3)
CREATE (dudeB3)<-[:FRIEND_OF]-(dudeC4)

MATCH (d:Dude) RETURN d

MATCH (le:Dude {name:"Lebowski"})<-[:FRIEND_OF]-(some:Dude)
RETURN some

MATCH (le:Dude {name:"Lebowski"})<-[:FRIEND_OF]-(someA:Dude)<-[:FRIEND_OF]-(someB:Dude)
RETURN someB

MATCH (le:Dude {name:"Lebowski"})<-[:FRIEND_OF*3]-(some:Dude)
RETURN DISTINCT some

MATCH (le:Dude {name:"Lebowski"})<-[:FRIEND_OF*3]-(some:Dude) RETURN some