我在SDN / RX 1.1的问题上绊脚石
<dependency>
<groupId>org.neo4j.springframework.data</groupId>
<artifactId>spring-data-neo4j-rx-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
在存储库类上使用自定义查询并尝试查询具有属性的多个关系时。
我有两个关系属性:
@RelationshipProperties
public class InRegionProperties {
@Id
@GeneratedValue
private Long id;
private String location;
private int distance;
public InRegionProperties (String location, int distance) {
this.id=null;
this.location = location;
this.distance = distance;
}
public Long getId () {
return id;
}
public String getLocation () {
return location;
}
public int getDistance () {
return distance;
}
public void setLocation (String location) {
this.location = location;
}
public void setDistance (int distance) {
this.distance = distance;
}
public void setId (Long id) {
this.id = id;
}
}
和
@RelationshipProperties
public class InWorldProperties {
@Id
@GeneratedValue
private Long id;
private String location;
public InWorldProperties (String location) {
this.id=null;
this.location = location;
}
public Long getId () {
return id;
}
public String getLocationInWorld () {
return location;
}
public void setLocationInWorld (String location) {
this.location = location;
}
public void setId (Long id) {
this.id = id;
}
}
对于两个节点,一个Region节点和一个World节点。我有一个最后一个节点,一个Lieu节点,所有这些都以这种方式关联:
(l:Lieu)-[:IN_REGION {location,distance}]->(r:Region)-[:IN_WORLD {location}]->(w:World)
然后,我在WorldRepository上使用自定义查询以获取世界中的区域,然后在Region中获取lieux。
@Query("MATCH (r:`Region`)-[:IN_WORLD]->(n:`World`) WHERE id(r)=$regionId WITH n, id(n) AS __internalNeo4jId__ "
+ "RETURN n{.description, __internalNeo4jId__: id(n), .name, __nodeLabels__: labels(n), "
+ "World_IN_WORLD_Region:[(n)<-[__relationship__:IN_WORLD]-(n_regions:Region) | n_regions{.description, __internalNeo4jId__: id(n_regions), .name, __nodeLabels__: labels(n_regions), "
+ "Region_IN_REGION_Lieu: [(n_regions)<-[__relationship__:`IN_REGION`]-(n_regions_lieux:Lieu) | n_regions_lieux{.description, __internalNeo4jId__: id(n_regions_lieux), .name, __nodeLabels__: labels(n_regions_lieux), __relationship__}], __relationship__}]"
+ "}")
Mono<World> getByRegion(Long regionId);
这是发生问题的地方:
为了获取所有的关系ipProperties,似乎SDN / RX映射引擎仅接受关系作为关系的别名。在Cypher(Neo4j浏览器)中此查询的结果是:
{
"name": "New Finn City",
"description": "Ville Monde, terre de la Ligue Des Héros.",
"__internalNeo4jId__": 61,
"World_IN_WORLD_Region": [
{
"__internalNeo4jId__": 14,
"__relationship__": {
"identity": 4,
"start": 14,
"end": 61,
"type": "IN_WORLD",
"properties": {
"location": "Sud Est"
}
},
"name": "Bio Town",
"description": "Le quartier réserve naturelle. La biosphère, en constante évolution grâce au Weillenium, y est préservée et vit en liberté protégée et surveillée.",
"Region_IN_REGION_Lieu": [],
"__nodeLabels__": [
"Region"
]
},
{
"__internalNeo4jId__": 15,
"__relationship__": {
"identity": 3,
"start": 15,
"end": 61,
"type": "IN_WORLD",
"properties": {
"location": "Nord"
}
},
"name": "Astro Town",
"description": null,
"Region_IN_REGION_Lieu": [],
"__nodeLabels__": [
"Region"
]
},
{
"__internalNeo4jId__": 13,
"__relationship__": {
"identity": 2,
"start": 13,
"end": 61,
"type": "IN_WORLD",
"properties": {
"location": "Est"
}
},
"name": "Electro Town",
"description": "Le quartier des savants et inventeurs, où les robots et machines alimentées en Weillenium sont omniprésentes.",
"Region_IN_REGION_Lieu": [],
"__nodeLabels__": [
"Region"
]
},
{
"__internalNeo4jId__": 12,
"__relationship__": {
"identity": 1,
"start": 12,
"end": 61,
"type": "IN_WORLD",
"properties": {
"location": "Nord Ouest"
}
},
"name": "Dark Town",
"description": "Le quartier pauvre, rongé par la criminalité, et le traffic de Weillenium. C'est le territoire de la Ligue des Villains.",
"Region_IN_REGION_Lieu": [],
"__nodeLabels__": [
"Region"
]
},
{
"__internalNeo4jId__": 11,
"__relationship__": {
"identity": 0,
"start": 11,
"end": 61,
"type": "IN_WORLD",
"properties": {
"location": "Sud Ouest"
}
},
"name": "Atom Town",
"description": "Le quartier central de New Finn City, où siège la Ligue des Héros. C'est le centre administratif du monde.",
"Region_IN_REGION_Lieu": [],
"__nodeLabels__": [
"Region"
]
}
],
"__nodeLabels__": [
"World"
]
}
的Lieux节点不是取出由于redondant使用的关系作为别名。当在cypher上为:IN_REGION关系使用另一个别名时,我得到了获取的Lieux,但是在SDN / RX中,我得到了以下错误:
Caused by: org.neo4j.driver.exceptions.value.Uncoercible: Cannot coerce NULL to Relationship
at org.neo4j.driver.internal.value.ValueAdapter.asRelationship(ValueAdapter.java:311)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.createInstanceOfRelationships(DefaultNeo4jConverter.java:499)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.lambda$populateFrom$6(DefaultNeo4jConverter.java:375)
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithAssociations(BasicPersistentEntity.java:380)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.map(DefaultNeo4jConverter.java:288)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.lambda$createInstanceOfRelationships$22(DefaultNeo4jConverter.java:496)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter$KnownObjects.computeIfAbsent(DefaultNeo4jConverter.java:566)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.createInstanceOfRelationships(DefaultNeo4jConverter.java:495)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.lambda$populateFrom$6(DefaultNeo4jConverter.java:375)
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithAssociations(BasicPersistentEntity.java:380)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.map(DefaultNeo4jConverter.java:288)
at org.neo4j.springframework.data.core.mapping.DefaultNeo4jConverter.read(DefaultNeo4jConverter.java:138)
... 48 more
映射过程似乎只接受关系作为具有要在@RelationshipProperties类中映射的属性的关系的别名。
有没有办法绕过这个问题?
谢谢大家的帮助。
首先,第一件事:现在有正式的SDN 6,它是SDN / RX的后继产品。半年前,我们停止了SDN / RX上的开发,而专注于新的SDN。从版本2.4开始,SDN 6可以与Spring Boot一起使用。
例如,在过去的几个月中,我们已经解决了命名大关系的问题。
如果你真的没有更新的机会,我可以看一下。如果需要,请添加评论。
您好,非常感谢,对于您的回复太晚表示抱歉。我设法绕过了这个问题,我可能会尽快迁移到SDN6。谢谢您的回答!