如何检查neo4j中节点属性的模式索引是否已存在? [英] How to check if a schema index already exists for a node's property in neo4j?

问题描述

我正在使用 IndexDefinition 用于在neo4j中填充给定属性上的索引.

I am using IndexDefinition for populating index over a given property in neo4j.

IndexDefinition indexDefinition = schema.indexFor(DynamicLabel.label("Person")).on("NodeType").create();

问题是当我再次使用索引填充的类似代码执行程序时，出现以下异常.

Problem is when I execute the program again with similar code for Index population, I get following exception.

 org.neo4j.kernel.api.exceptions.schema.AlreadyIndexedException: Already indexed :label[0](property[0]).
    at org.neo4j.kernel.impl.api.DataIntegrityValidatingStatementContext.checkIndexExistence(DataIntegrityValidatingStatementContext.java:107)
    at org.neo4j.kernel.impl.api.DataIntegrityValidatingStatementContext.indexCreate(DataIntegrityValidatingStatementContext.java:78)

我只想检查某个属性的索引是否已经存在，那么以后就不应该进行索引填充了.

I just want to check if an Index for a property is already there, then no subsequent Index population should take place.

推荐答案

为什么在尝试创建标签并获取(正确的)异常之前不检查标签的索引?

why don't you check the Indexes for a Label before trying to create it and getting a (correct) exception?

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