Neo4j入门实战

1.介绍

2.实战

Neo4j的sql语句

1.创建多个节点

CREATE (:student {name:'小张',age:20}),(:student {name:'彭莎丽',age:18})
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2.匹配节点将节点删除

这样删除是将student中的条件节点删除——>会变成空白节点

match (m:student {name:"Fairy同学"}) remove m:student
MATCH (student) where id(student)=60 delete student
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要彻底删除，不指定特定的图即可 delete

MATCH (n {name:"Fairy同学"}) delete n
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2.复合删除

MATCH (n) WHERE id(n) = 2066 DETACH DELETE n
RETURN n
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3.给指定的节点添加属性

MATCH (n:student {name:"邬雨航"}) set n.address='长沙' return n
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4.给指定节点创建关系

match (n:student {name:'邬雨航'}),(m:student{name:'Fairy同学'})
create (n)-[r:`别名`{relation:'别名'}]->(m) return r
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MATCH (n:student {name:'邬雨航'}),(m:student {name:'彭莎丽'})
create (n)-[r:`密友`{relation:'密友'}]->(m) return r
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学校和学生之间的关系：

match (n:student {name:'邬雨航'}),(m:school{name:'长沙理工大学城南学院'})
create (n)-[r:`所在学校`{relation:'学校'}]->(m) return r
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1.指定路径

Match (p:student) -[*]->(s:student) where id(p)=64 return s
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2.给节点创建全路径

create p=(:student{name:'邬雨航'})-[:职业]->(:offer{name:'开发工程师'})<-[:职业]-
(:student {name:'小张'}) return p
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3.删除指定关系

MATCH (p1:student {name:'邬雨航'})-[r:`所在学校`]-(p2:student {name:'彭莎丽'}) 
DELETE r
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4.查询某个节点的所有关系

1.第一种，单向:

MATCH (n:student {name:'邬雨航'})-->(b) return n,b
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2.第二种，双向:

MATCH (n:student {name:'校长'})<-->(b) return n,b
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5.级联删除节点的关系

//1.指定条件
MATCH (r) WHERE id(r) = 60 DETACH DELETE r
//2.全删除
MATCH (r) DETACH DELETE r
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5.添加唯一约束

添加name的唯一约束

CREATE CONSTRAINT ON (cc:student)
ASSERT cc.name IS UNIQUE
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6.常见函数

1.统计节点数count

match (n:student) return count(n)
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2.MAX()和SUM()函数的使用

MATCH (s:student) RETURN MAX(s.age),SUM(s.age)
```![在这里插入图片描述](https://img-blog.csdnimg.cn/6c4e0d75fb5e44dba274f2231c6b5659.png)



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