Neo4j 基本语法

一、基本语法

1、新建节点

（1）基本语法：

() 代表节点

示例：

CREATE (u:User {uid:970939424 })       // 节点类型为User，属性值为uid=970939424CREATE (u:Round {rid:7194842697444819113 })   // 节点类型为Round对局，属性值为rid:7194842697444819113

2、新建关联边

基本语法：

()-[]->() 代表关联边【需先建立节点，再建立关联边】

示例：

match (n:User {uid:970939424 }),(m:User{uid:658505284}),(r:RoundId {rid:7194842697444819113 })

CREATE (n)-[user_game1:user_game_roundid]-> (r)<-[user_game:user_game_roundid]-(m)

CREATE (u)-[user_game:user_game_roundid}]->(r)

sed -i 's/"//g' 000000_0

删除边：

MATCH (u:User {uid: 1042526861} )-[r : user_game_mpuid ]->(i:Mpuid {mp_uid: "501045_936304347_1042526861" } ) delete r

边更新：

MATCH (u:User {uid: 1042526861} )-[r : user_game_mpuid ]->(i:Mpuid {mp_uid: "501045_342594656_1042526861" } ) SET r={ same_round_cnt: 3 ,win_round_cnt: 3 ,lost_round_cnt: 0 ,coin_change_amt: 403 ,feed_cnt: 0 }

3、创建唯一约束：

基于语法：

()-[]->() 代表关联边【需先建约束，再导入节点数据】

示例：

CREATE CONSTRAINT ON (c:User) ASSERT c.uid IS UNIQUE

CREATE CONSTRAINT ON (r:Round) ASSERT r.rid IS UNIQUE

CREATE CONSTRAINT ON (m:Mac) ASSERT m.mac IS UNIQUE

CREATE CONSTRAINT ON (m:IP) ASSERT m.ip IS UNIQUE

CREATE CONSTRAINT ON (c:IDCard) ASSERT c.idcard IS UNIQUE

CREATE CONSTRAINT ON (m:Mpuid) ASSERT m.mp_uid IS UNIQUE

4、创建索引：

基于语法：

CREATE INDEX FOR (m:Movie) ON (m.released)

示例：CREATE INDEX ON :User(uid)

CREATE INDEX ON :Round(rid)

5、查询：

（1）

MATCH (nineties:Movie) WHERE nineties.released >= 1990 AND nineties.released < 2000 RETURN nineties.title

（2）

用户两度关联用户查询，如果节点多不加limit 不会展示关联

MATCH p = (u:User)-[*2]-(u2:User) WHERE u.uid=171751482 RETURN p limit 10

6、使用可变长度模式找到电影和演员最多4“跳”远离凯文培根

MATCH (bacon:Person {name:"Kevin Bacon"})-[*1..4]-(hollywood)

RETURN DISTINCT hollywood

7、最短路径查询：

Use the built-in shortestPath() algorithm to find the "Bacon Path" to Meg Ryan.

MATCH p=shortestPath(

(bacon:Person {name:"Kevin Bacon"})-[*]-(meg:Person {name:"Meg Ryan"})

)

RETURN p

8、删除点边

MATCH (n) DETACH DELETE n

MATCH (u:User {uid:toInt(line[0]) } )-[r:user_game_mpuid]-(i:Mpuid {mp_uid: line[1]} )
DELETE r

9、查看历史命令：

:history

10、先导入点，再导入边；

11、节点属性更新

:auto USING periodic commit 3000
LOAD CSV FROM "file:///risk_export_20230613/node/attr_usr.csv" AS line fieldterminator ","
MERGE (u:User {uid:toInt(line[0])})
ON MATCH  SET u={uid:toInt(line[0]),recharge_amt_td:toInt(line[1]),is_login_mps_anjian_15d:toInt(line[2]),is_login_mps_emulator1_30d:toInt(line[3])}