Spring Data Neo4j中的DynamicRelationshipType或在运行时定义关系类型 [英] DynamicRelationshipType in Spring Data Neo4j or defining relationship types at runtime

问题描述

我可以在运行时指定关系类型吗?

Can I specify relationship type at runtime??

我正在使用

@Fetch
@RelatedToVia(type="RELATED_IN_SOME_WAY", direction = Direction.BOTH)
Set<ThingRelationship> relationships = new HashSet<ThingRelationship>();

ThingRelationship是

where ThingRelationship is

@RelationshipEntity
public class ThingRelationship {

public ThingRelationship() {
    super();
}

//incremental neo4j set ID
@GraphId Long nodeId;

//Start and end nodes
@StartNode Thing startThing;
@EndNode Thing endThing;

//Relationship Type
@org.springframework.data.neo4j.annotation.RelationshipType
String relationship;

但是我不想在编译时而是在运行时指定关系类型( type ="RELATED_IN_SOME_WAY" ).当我删除type ="RELATED_IN_SOME_WAY时，出现错误，必须定义默认类型

However I DONT want to specify the relationship type (type="RELATED_IN_SOME_WAY") at compile time but rather at runtime. When I remove type="RELATED_IN_SOME_WAY I get an error that a default type must be defined

在Neo4j中，我认为这样的运行时关系类型需要使用 DynamicRelationshipType ，但是我不认为Spring Data Neo4j支持此概念.

In Neo4j such a runtime relationship type I think requires the use of DynamicRelationshipType however I dont think the Spring Data Neo4j supports this concept.

我可以纠正吗，如果可以，这个问题有解决办法吗?我是否需要转储Spring Data Neo4j并转而使用Core API?

Am I correct and if so is there anyway around this problem? Do I need to dump Spring Data Neo4j and go to use the Core API instead?

推荐答案

• 在Neo4j中，我认为这样的运行时关系类型需要使用DynamicRelationshipType，但是我不认为Spring Data Neo4j支持此概念.

来自

注意

因为动态类型信息是动态的，所以它通常是动态的 无法使用SDN向后读取映射.关系 仍然存在，但SDN无法帮助您访问它，因为它不存在 知道你给它什么类型的.另外，由于这个原因，我们要求您 指定默认的关系类型，以便我们至少可以尝试 反向映射.

Because dynamic type information is, well, dynamic, it is generally not possible to read the mapping backwards using SDN. The relationship still exists, but SDN cannot help you access it because it does not know what type you gave it. Also, for this reason, we require you to specify a default relationship type, so that we can at least attempt the reverse mapping.

因此，即使仍然创建动态关系，它也不能使用该信息从Neo4j db中检索回节点/关系.默认关系是必需的，以便SDN至少可以返回已知关系.

So while the dynamic relationship is still created, it can't use that information to retrieve the nodes/relationships back from the Neo4j db. The default relationship is required so that SDN can at least return the known relationship.

• 我可以纠正吗，如果可以，这个问题有解决办法吗?我是否需要转储Spring Data Neo4j并转而使用Core API?

您可以使用SDN使用@RelationshipType创建所需的所有动态关系，但无法使用默认API找回它.您可以使用@Query编写自己的Cypher或编写遍历代码，并将其附加到存储库或节点属性.

You can use the SDN to create all dynamic relationships you want using the @RelationshipType but you can't retrieve it back using the default API. You can use write your own Cypher or write traversal code and attach it to your repository or a node property using @Query.

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