Neo4J：好友推荐简单示例

雨点打透心脏的1/2处 2023-06-09 12:22 89阅读 0赞

说明：该例子来源于《Neo4j 3.x 入门经典》

### 1、初始化数据 ###

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"})

![在这里插入图片描述][20191021102803863.png]

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)

![在这里插入图片描述][20191021102907907.png]

MATCH (d:Dude) RETURN d

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70]

### 2、好友推荐 ###

(1) Lebowski的朋友

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

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70 1]  
(2) Lebowski的朋友的朋友

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

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70 2]  
(3) Lebowski的朋友的朋友的朋友

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

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70 3]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70 4]

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

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5neXVxaWFuZw_size_16_color_FFFFFF_t_70 5]

[20191021102803863.png]: /images/20230531/08c8cf4a18ab4c459509ce37ef3d9a47.png
[20191021102907907.png]: /images/20230531/73121fe69664448f80ef685ea2311da2.png
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