java - 如何避免重复节点？

Question

我正在编写一个java项目，使用密码查询在neo4j中插入数据。我想阻止 neo4j 创建重复节点，而不是将另一个节点与现有节点链接。

CREATE (n1:node {name:'Adam'})-[:born_in]->(n2:node {name:'USA'})
//and again 
CREATE (n1:node {name:'Adam'})-[:worked_at]->(n2:node {name:'Apple'})

我想创建一个 Adam 节点和另外两个节点，即 USA 和 Apple。 java中是否有任何检查来避免重复？

Answer 1

best way to create relationship between two nodes is

first get the two nodes.if they doesn't exists then create. Once the nodes are loaded, then simply create a relationship between them

根据您的情况，先使用MERGE 创建节点，然后使用关系

MERGE (n1:node {name:'Adam'})
MERGE (n2:node {name:'USA'})
MERGE (n1)-[r:born_in]->(n2)

此链接将帮助您理解MERGE

https://neo4j.com/docs/cypher-manual/current/clauses/merge/