[TOC] > [參考](https://zhuanlan.zhihu.com/p/88745411) ## 語法 ## 刪除數據庫 ``` MATCH (n) DETACH DELETE n ``` MATCH是匹配操作，而小括號()代表一個節點node（可理解為括號類似一個圓形），括號里面的n為標識符 ## 創建節點 **創建多人物個節點** ``` CREATE (n:Person {name:'John'}) RETURN n CREATE (n:Person {name:'Sally'}) RETURN n CREATE (n:Person {name:'Steve'}) RETURN n CREATE (n:Person {name:'Mike'}) RETURN n CREATE (n:Person {name:'Liz'}) RETURN n CREATE (n:Person {name:'Shawn'}) RETURN n ``` `CREATE`是**創建**操作，`Person`是**標簽**，代表節點的類型。花括號{}代表節點的**屬性**，屬性類似Python的字典 **創建地區節點** ``` CREATE (n:Person {name:'Sally'}) RETURN n CREATE (n:Person {name:'Steve'}) RETURN n CREATE (n:Person {name:'Mike'}) RETURN n CREATE (n:Person {name:'Liz'}) RETURN n CREATE (n:Person {name:'Shawn'}) RETURN n ``` ## 創建關系 ``` MATCH (a:Person {name:'Shawn'}), (b:Person {name:'Sally'}) MERGE (a)-[:FRIENDS {since:2001}]->(b) // 創建更多 MATCH (a:Person {name:'Shawn'}), (b:Person {name:'John'}) MERGE (a)-[:FRIENDS {since:2012}]->(b) MATCH (a:Person {name:'Mike'}), (b:Person {name:'Shawn'}) MERGE (a)-[:FRIENDS {since:2006}]->(b) MATCH (a:Person {name:'Sally'}), (b:Person {name:'Steve'}) MERGE (a)-[:FRIENDS {since:2006}]->(b) MATCH (a:Person {name:'Liz'}), (b:Person {name:'John'}) MERGE (a)-[:MARRIED {since:1998}]->(b) ``` 創建 a->b 兩個人的邊,原因為 FRIENDS 創建人與地區的邊 ``` MATCH (a:Person {name:'John'}), (b:Location {city:'Boston'}) MERGE (a)-[:BORN_IN {year:1978}]->(b) // 創建更多 MATCH (a:Person {name:'Liz'}), (b:Location {city:'Boston'}) MERGE (a)-[:BORN_IN {year:1981}]->(b) MATCH (a:Person {name:'Mike'}), (b:Location {city:'San Francisco'}) MERGE (a)-[:BORN_IN {year:1960}]->(b) MATCH (a:Person {name:'Shawn'}), (b:Location {city:'Miami'}) MERGE (a)-[:BORN_IN {year:1960}]->(b) MATCH (a:Person {name:'Steve'}), (b:Location {city:'Lynn'}) MERGE (a)-[:BORN_IN {year:1970}]->(b) ``` 創建后效果  ## 查詢 查詢下所有在Boston出生的人物 ``` MATCH (a:Person)-[:BORN_IN]->(b:Location {city:'Boston'}) RETURN a,b ```  查詢所有對外有關系的節點 ``` MATCH (a)-->() RETURN a ```  查詢所有有關系的節點 ``` MATCH (a)--() RETURN a ```  查詢所有對外有關系的節點，以及關系類型 ``` MATCH (a)-[r]->() RETURN a.name, type(r) ```  查詢所有有結婚關系的節點 ``` MATCH (n)-[:MARRIED]-() RETURN n ```  查找某人的朋友的朋友 ``` MATCH (a:Person {name:'Mike'})-[r1:FRIENDS]-()-[r2:FRIENDS]-(friend_of_a_friend) RETURN friend_of_a_friend.name AS fofName ```  ## 創建節點并建好關系 ``` CREATE (a:Person {name:'Todd'})-[r:FRIENDS]->(b:Person {name:'Carlos'}) ```  ## 增加/修改節點的屬性 ``` MATCH (a:Person {name:'Liz'}) SET a.age=34 MATCH (a:Person {name:'Shawn'}) SET a.age=32 MATCH (a:Person {name:'John'}) SET a.age=44 MATCH (a:Person {name:'Mike'}) SET a.age=25 ``` ## 刪除節點的屬性 ``` MATCH (a:Person {name:'Mike'}) SET a.test='test' MATCH (a:Person {name:'Mike'}) REMOVE a.test ``` ## 刪除節點 ``` MATCH (a:Location {city:'Portland'}) DELETE a ``` ## 刪除有關系的節點 ``` MATCH (a:Person {name:'Todd'})-[rel]-(b:Person) DELETE a,b,rel ```