如何在 Neo4J 中创建涉及多个属性的唯一约束 [英] How to create unique constraint involving multiple properties in Neo4J

问题描述

我知道我可以使用 Cypher 在单个属性上创建唯一约束，例如 CREATE CONSTRAINT ON (p:Person) ASSERT p.name IS UNIQUE.但我想知道是否可以创建一个涉及多个属性的唯一约束.如果是，怎么办?

I know I can create a unique constraint on a single property with Cypher like CREATE CONSTRAINT ON (p:Person) ASSERT p.name IS UNIQUE. But I was wondering whether it is possible to create a unique constraint which involves multiple properties. If so, how?

推荐答案

neo4j (2.0.1) 目前不支持同时覆盖多个属性的唯一性约束.

neo4j (2.0.1) does not currently support a uniqueness constraint that covers multiple properties simultaneously.

但是，根据您的用例，我可以想到一种可能可以接受的解决方法.假设您希望属性 a、b 和 c 作为一个组是唯一的.您可以添加一个额外的属性 d，它连接 a、b 和 c 的字符串化值，使用适当的分隔符分隔子字符串(例如，a/b 分隔符是一个永远不会出现的字符)在 a 或 b).然后，您可以在 d 上创建唯一性约束.

However, I can think of a workaround that might be acceptable, depending on your use cases. Let's say you want properties a, b, and c to be unique as a group. You can add an extra property, d, that concatenates the stringified values of a, b, and c, using appropriate delimiter(s) to separate the substrings (such that, for example, the a/b delimiter is a character that never appears in a or b). You can then create a uniqueness constraint on d.

[更新]

Neo4j 3.3 添加了对涵盖多个属性的唯一性约束的支持，通过 节点键约束.但是，此功能仅在企业版中可用.

Neo4j 3.3 added support for uniqueness constraints that cover multiple properties, via node key constraints. However, this feature is only available in the Enterprise Edition.

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