Spring Data Neo4j - @RelationshipType 问题 [英] Spring Data Neo4j - @RelationshipType issues

问题描述

当关系类型用 @RelationshipType 字段注释时，我很难检索关系.

I'm having difficulties retrieving relationships when the relationship type is annotated with a @RelationshipType field.

关系在 Neoclipse 中看起来是正确的，但我在我的应用程序中没有检索到任何结果.

The relationships look correct in Neoclipse, but I'm retrieving no results in my application.

不起作用的代码是(简化):

The code that doesn't work is (simplified):

@NodeEntity
public abstract class Entity {

    @RelatedToVia
    private Collection<Relationship> relationships;

    public Relationship relatedTo(Entity entity, String type) {
        Relationship relationship = new Relationship(type, this, entity);
        relationships.add(relationship);

        return relationship;
    }

    ...
}

和:

@RelationshipEntity
public class Relationship {

    @RelationshipType
    private String type;

    ...
 }

有效的代码是:

@RelationshipEntity(type = "something")
public class Relationship {

   ...
}

但是，这不适合我的用例(我在 Entity 实例的任意组合之间有一堆不同的 Relationship 类型.

However, this doesn't suit my use case (I have a bunch of different Relationship types between arbitrary combinations of Entity instances.

完整的测试代码如下.Agency 和 Item 都是 Entity 的子类.

The full test code is below. Agency and Item are both subclasses of Entity.

// Create first entity
Agency arnz = agencyRepository.save(new Agency());
arnz.setCode("ARNZ");
agencyRepository.save(arnz);

// Create second entity
Item r123 = itemRepository.save(new Item());
r123.setCode("R123");

// Create parent/child relationship between entities
r123.relatedTo(arnz, EntityRelationshipType.PARENT);
itemRepository.save(r123);

// Retrieve entity from database
Entity entity = itemRepository.findByCode("R123");

// Verify that relationship is present
assertThat(entity.getRelationships().iterator().hasNext(), is(true));

最后一行是测试失败的地方.有什么线索吗?

The final line is where the test is failing. Any clues?

M

附注.我是 Neo4j 的业余爱好者，碰巧找到了 @RelationshipType，所以我很可能在做一些可笑的错误.希望如此！

PS. I'm a rank amateur with Neo4j and just happened to find @RelationshipType, so I may well be doing something laughably wrong. I hope so!

推荐答案

很抱歉让您失望了，但是在检索过程中，现在的代码不会查找类型类，而是查找来自 @RelatedToVia<的类型/code> 或 @RelationshipEntity 或字段名称 relationships 作为关系类型.但是你提出了一个有效的观点，你能在 JIRA 中提出问题吗?

Sorry to disappoint you, but during the retrieval the code right now doesn't look for the type class but rather for the type from @RelatedToVia or @RelationshipEntity or the field name relationships as relationship-type. But you're making a valid point, can you please raise in issue in JIRA?

您是否查看了 template.getRelationshipsBetween ?

你为什么不为你的关系创建单独的类?这种方法的用例是什么?

Why don't you create individual classes for your relationships? What is the use-case for this approach?

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