等同于SDN4中的template.createRelationBetween [英] equivalent of template.createRelationBetween in SDN4

问题描述

我的项目当前使用的是Spring-Data-Neo4J 3.3.0，我正在尝试使用新的4.0.0.Release版本. 在我的代码中，我有以下代码:

My project is currently use Spring-Data-Neo4J 3.3.0 and I'm trying to use the new 4.0.0.Release version. In my code I have the following code :

neo4jTemplate.createRelationshipBetween(eltOrRel, attribute, valueClass, GraphRelationType.HAS_ATT_VALUE, true)

此代码等效(使用请在新版本的SDK中使用api 中的此方法?

What is the equivalent of this code (which is use this method in api in the new version of SDK please ?

更特别的是，我不知道如何创建给定类型的关系，而是为特定类创建关系.请问如何在密码中写出这样的作品?

More especially I don't know how to create a relation of a given type but for a specific class. How can I write such a creation in cypher please ?

@Luanne这是我的问题的一个小例子.

@Luanne Here is a little example of my problem.

类元素:

@NodeEntity
public class Element {

@GraphId
private Long id;

private int age;

private String  uuid;

@Relationship(type = "HAS_ATT_VALUE")
private Set<HasAttValue> values = new HashSet<HasAttValue>();
...

Class Attribute:

Class Attribute :

@NodeEntity
public class Attribute {
@GraphId
private Long id;

private String attName;

和类HasAttValue:

And class HasAttValue :

@RelationshipEntity(type = "HAS_ATT_VALUE")
public class HasAttValue {

@GraphId
private Long id;

@StartNode
Element element;

@EndNode
Attribute attribute;

private String value;

public HasAttValue() {
}

public HasAttValue(Element element, Attribute attribute, String value) {
    this.element = element;
    this.attribute = attribute;
    this.value = value;
    this.element.getValues().add(this);
}

在第一种情况下，所有内容都像一个超级按钮，就像您在示例中一样，我具有下图(在服务器浏览器中查看)，其值位于HAS_ATT_VALUE RelationshipEntity上:

In this first case, everything works like a charm, and, as in your example I have the following graph (seeing in the server browser) with my value on the HAS_ATT_VALUE relationshipEntity:

(Element)->[HAS_ATT_VALUE]->(attribute)

但是我的问题是在以下情况下(在以前的SDN上运行良好).而不是HasAttValue上一课，我有:

But my problem is in the following case (which was working well with previous SDN). Instead of the HasAttValue previous class, I have :

@RelationshipEntity(type = "HAS_ATT_VALUE")
public abstract class HasAttValue<T> {

@GraphId
private Long id;

@StartNode
Element element;

@EndNode
Attribute attribute;

private T value;

public HasAttValue() {
}

public HasAttValue(Element element, Attribute attribute, T value) {
    this.element = element;
    this.attribute = attribute;
    this.value = value;
    this.element.getValues().add(this);
}

具有两个子类. 第一个:

with for example two subclasses. First one :

public class HasBooleanValue extends HasAttValue<Boolean> {

public HasBooleanValue() {
}

public HasBooleanValue(Element elt, Attribute attribut, Boolean value) {
    super(elt, attribut, value);
}
}

第二个:

public class HasStringValue extends HasAttValue<String> {

private String locale;

public HasStringValue() {
}

public HasStringValue(Element element, Attribute attribut, String value)   {
    super(element, attribut, value);
}

在这种情况下，图形如下所示:

In this case the graph is like the following :

(element)->[HAS_ATT_VALUE]->(HasBooleanValue|HasStringValue)->[ATTRIBUTE]->(Attribute)

和图形中的另一个弧 (element)<-[ELEMENT]-(HasBooleanValue | HasStringValue)

and another arc in the graphe (element)<-[ELEMENT]-(HasBooleanValue|HasStringValue)

那么我该怎么做才能始终具有(element)-> [HAS_ATT_VALUE]->(attribute)，其中"has_att_value"是一个包含数据但在我的Java代码中具有不同实现的关系性?再次，当我使用neo4jTemplate.createRelationshipBetween(eltOrRel，attribute，valueClass，GraphRelationType.HAS_ATT_VALUE，true)创建我的"hasAttValue" RelationshipEntity时，这在SDN3中运行良好.

So how can I do to always have (element)->[HAS_ATT_VALUE]->(attribute) where "has_att_value" is a relationshipentity containing datas but having diffent impletations in my java code ? Again, this was working well in SDN3 when I used the neo4jTemplate.createRelationshipBetween(eltOrRel, attribute, valueClass, GraphRelationType.HAS_ATT_VALUE, true) to create my "hasAttValue" relationshipEntity.

非常感谢您

推荐答案

在SDN 4.0中，不需要使用Neo4jTemplate方法显式创建关系.保留定义了@Relationships的实体就足以 @ RelationshipEntity .

In SDN 4.0, relationships do not need to be created explicitly using Neo4jTemplate methods. Persisting the entity on which @Relationships are defined is enough to create relationships. If you have properties on the relationship, then you'd need a @RelationshipEntity.

可以在此处找到SDN 4.0中的对象模型的说明

An explanation of object models in SDN 4.0 can be found here http://graphaware.com/neo4j/2015/09/03/sdn-4-object-model.html

根据来自@clement的其他信息进行更新:

只需将注释从HasAttValue类移动到每个子类，例如

Just move the @RelationshipEntity annotation from the HasAttValue class to each subclass, for example

@RelationshipEntity(type = "HAS_ATT_VALUE")
public class HasBooleanValue extends HasAttValue<Boolean> {

请注意，由于有关抽象关系实体的问题已得到解决，因此您将需要最新的OGM快照.请使用

Note that you will need the latest OGM snapshot since an issue around abstract relationship entities was just fixed. Please use

  <dependency>
       <groupId>org.neo4j</groupId>
       <artifactId>neo4j-ogm</artifactId>
       <version>1.1.3-SNAPSHOT</version>
  </dependency>
 <repository>
       <id>neo4j-snapshots</id>
       <url>http://m2.neo4j.org/content/repositories/snapshots</url>
       <snapshots>
           <enabled>true</enabled>
       </snapshots>
  </repository> 

或使用SDN 4.1快照

Or use the SDN 4.1 snapshot

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-neo4j</artifactId>
    <version>4.1.0.BUILD-SNAPSHOT</version>
</dependency>

然后您的图形应该看起来像

Then your graph should look like

直接使用Cypher并不是一个好主意，因为您必须能够查找节点(可能是通过ID)，这意味着必须首先保存它们.

Using Cypher directly is not a good idea as you'd have to be able to look up the nodes (maybe by ID), which would mean they have to be saved first.

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