neo4j 约束(CONSTRAINT)

1.创建约束

CREATE (n:test{name:'wang'})
CREATE CONSTRAINT ON (n:test) ASSERT n.name IS UNIQUE

2.重复添加元素

CREATE (n:test{name:'wang'})

报错

Neo.ClientError.Schema.ConstraintValidationFailed
Node(0) already exists with label `test` and property `name` = 'wang'

注意:
1)约束只对指定的lable下面的字段有效,其他label不受影响
2)一次只能给一个lable添加约束

参考:
https://blog.youkuaiyun.com/qq_38737992/article/details/89219537