neo4j cypher-remove

二、remove 移除

示例的数据结构：

<img src="https://i.loli.net/2020/10/28/6RS7gJjxpmhLyFn.png" alt="image-20201028222814040" style="zoom:80%;" />

创建的语句：

create p=(peter:Swedish:German {name:'Peter', age:34})<-[:KNOWS]-(andy:Swedish {name:'Andy', age:36})-[:KNOWS]->(timothy:Swedish {name:'Timothy', age:25}) 
return p

<img src="https://i.loli.net/2020/10/28/IeDmr1ZEhVxSOcp.png" alt="image-20201028222401520" style="zoom:80%;" />

1. 移除单个属性

match (a {name:'Andy'}) remove a.age 
return a.name, a.age

删除之前：

<img src="https://i.loli.net/2020/10/28/DWY2EHxcR8kN9IJ.png" alt="image-20201028225605822" style="zoom:80%;" />

删除之后：

<img src="https://i.loli.net/2020/10/28/VSXlQbgE7W6rTGN.png" alt="image-20201028225816898" style="zoom:80%;" />

2. 移除所有属性

remove 不能用来从节点和关系中移除现有的节点和关系

使用 set 来移除所有属性：

match (p {name:'Peter'}) set p = {} 
return p.name, p.age

3. 从一个节点中移除一个标签

match (n {name:'Peter'}) remove n:German 
return n.name, labels(n)

未移除之前：

<img src="https://i.loli.net/2020/10/28/Bz6EdOVPqhoySu1.png" alt="image-20201028231152729" style="zoom:80%;" />

移除之后：

<img src="https://i.loli.net/2020/10/28/S2X7YnBvQUMVq8r.png" alt="image-20201028231254707" style="zoom:80%;" />

<img src="https://i.loli.net/2020/10/28/LdeEODHM5Ni7vFr.png" alt="image-20201028230949892" style="zoom: 67%;" />

4. 从一个节点移除多个标签

match (n {name:'Peter'}) remove n:German:Swedish 
return n.name , labels(n)

移除之前：

<img src="https://i.loli.net/2020/10/28/Bz6EdOVPqhoySu1.png" alt="image-20201028231152729" style="zoom:80%;" />

移除之后：

<img src="https://i.loli.net/2020/10/28/jGXhlC7i3HfbvmP.png" alt="image-20201028233318933" style="zoom:80%;" />

<img src="https://i.loli.net/2020/10/28/VNkIbxhiWyAnaT4.png" alt="image-20201028232750139" style="zoom:80%;" />