1问题摘要
RelationshipEntity
似乎
就像事务被回滚一样。我的期望是只有
关系实体
检查中的关系被更新,所有其他关系未被触及。
2初始情况
-
运行Neo4j 3.4.7、Spring Boot v2.0.5.RELEASE、Spring v5.0.9.RELEASE
-
没有显式使用事务
-
简化图架构:
三。目标实际比较
3.1. 时间顺序
根据图表模式的简化用例可以总结如下:
-
ClassC
节点
-
为他们找到各种相关的
ClassB
ClassA
)
-
对于每个已识别的
创建
ClassD
B类
和丰富的关系
CDMapping
C类
所描述的完整块在第一次运行时运行良好。各种各样的
RelationshipEntitys
之间
C类
D类
设置了“Default Value”属性后,最后一个rich关系将接收预期的值“Special Value”。
3.3详细问题
关系实体
C类
和
D类
-上一次运行的属性被意外地设置回“Default Value”,替换原来的“Special Value”。
3.4 Neo4j生成的查询
cdMappingDAO.save(cdMapping);
:
UNWIND {rows} as row MATCH (startNode) WHERE ID(startNode) = row.startNodeId WITH row,startNode MATCH (endNode) WHERE ID(endNode) = row.endNodeId CREATE (startNode)-[rel:`MAPS_TO`]->(endNode) SET rel += row.props RETURN row.relRef as ref, ID(rel) as id, {type} as type with params {type=rel, rows=[{startNodeId=91, relRef=-45, endNodeId=115, props={attribute=Default Value}}]}
UNWIND {rows} as row MATCH (startNode) WHERE ID(startNode) = row.startNodeId WITH row,startNode MATCH (endNode) WHERE ID(endNode) = row.endNodeId MERGE (startNode)-[rel:`CONTAINS`]->(endNode) RETURN row.relRef as ref, ID(rel) as id, {type} as type with params {type=rel, rows=[{startNodeId=88, relRef=-49, endNodeId=115, props={}}, {startNodeId=92, relRef=-51, endNodeId=91, props={}}, {startNodeId=88, relRef=-54, endNodeId=93, props={}}, {startNodeId=89, relRef=-56, endNodeId=94, props={}}, {startNodeId=92, relRef=-57, endNodeId=90, props={}}]}
UNWIND {rows} as row MATCH (n) WHERE ID(n)=row.nodeId SET n:`ClassA`:`Entity` SET n += row.props RETURN row.nodeId as ref, ID(n) as id, {type} as type with params {type=node, rows=[{nodeId=92, props={name=Class A}}]}
UNWIND {rows} as row MATCH (n) WHERE ID(n)=row.nodeId SET n:`ClassB`:`Entity` SET n += row.props RETURN row.nodeId as ref, ID(n) as id, {type} as type with params {type=node, rows=[{nodeId=88, props={name=Class B1}}, {nodeId=89, props={name=Class B2}}]}
UNWIND {rows} as row MATCH (n) WHERE ID(n)=row.nodeId SET n:`ClassD`:`Entity` SET n += row.props RETURN row.nodeId as ref, ID(n) as id, {type} as type with params {type=node, rows=[{nodeId=115, props={}}, {nodeId=93, props={}}, {nodeId=94, props={}}]}
UNWIND {rows} as row MATCH (n) WHERE ID(n)=row.nodeId SET n:`ClassC`:`Entity` SET n += row.props RETURN row.nodeId as ref, ID(n) as id, {type} as type with params {type=node, rows=[{nodeId=90, props={name=Class C1}}, {nodeId=91, props={name=Class C2}}]}
UNWIND {rows} AS row MATCH ()-[r]-() WHERE ID(r) = row.relId SET r += row.props RETURN ID(r) as ref, ID(r) as id, {type} as type with params {rows=[{relId=104, props={attribute=Default Value}}, {relId=106, props={attribute=Default Value}}], type=rel}
4有待解决的挑战
你能给我一个建议,为什么属性值会被重置,由什么组件重置?我怎样才能保证
关系实体
5代码段
@Component
public class GraphHandler implements CommandLineRunner {
private ClassADAO classADAO;
private ClassBDAO classBDAO;
private ClassCDAO classCDAO;
private ClassDDAO classDDAO;
private CDMappingDAO cdMappingDAO;
private SessionFactory sessionFactory;
@Autowired
public GraphHandler(ClassADAO classADAO, ClassBDAO classBDAO, ClassCDAO classCDAO, ClassDDAO classDDAO, CDMappingDAO cdMappingDAO, SessionFactory sessionFactory) {
this.classADAO = classADAO;
this.classBDAO = classBDAO;
this.classCDAO = classCDAO;
this.classDDAO = classDDAO;
this.cdMappingDAO = cdMappingDAO;
this.sessionFactory = sessionFactory;
}
public void run(String... args) {
createInitialModel();
runUseCase();
}
private void createInitialModel() {
ClassA classA = new ClassA("Class A");
ClassB classB1 = new ClassB("Class B1");
ClassB classB2 = new ClassB("Class B2");
ClassC classC1 = new ClassC("Class C1");
ClassC classC2 = new ClassC("Class C2");
classA.getClassBs().addAll(Arrays.asList(classB1, classB2));
classA.getClassCs().addAll(Arrays.asList(classC1, classC2));
classADAO.save(classA);
classBDAO.save(classB1);
classBDAO.save(classB2);
classCDAO.save(classC1);
classCDAO.save(classC2);
}
private void runUseCase() {
Iterable<ClassC> classCs = classCDAO.findAll();
for (ClassC classC : classCs) {
ClassD rememberedClassD = null;
List<ClassB> classBs = classBDAO.findClassBSelection(classC.getId());
for (ClassB classB : classBs) {
ClassD classD = new ClassD();
classD.setClassB(classB);
classB.getClassDs().add(classD);
classDDAO.save(classD);
rememberedClassD = classD;
CDMapping cdMapping = new CDMapping(classC, classD, "Default Value");
cdMappingDAO.save(cdMapping); // <-- here the problem occurs
}
// choosing the last created relationship (ClassC-ClassD) and mark it
CDMapping relationship = cdMappingDAO.getRelationshipByClassCAndClassD(classC.getId(), rememberedClassD.getId());
relationship.setAttribute("Special Value");
cdMappingDAO.save(relationship);
}
}
}
5.2 CDM映射
@RelationshipEntity(type = "MAPS_TO")
public class CDMapping {
@Id
@GeneratedValue
private Long id;
@StartNode
private ClassC classC;
@EndNode
private ClassD classD;
private String attribute;
public CDMapping(ClassC classC, ClassD classD, String attribute) {
this.classC = classC;
this.classD = classD;
this.attribute = attribute;
classC.getCdMappings().add(this);
classD.getCdMappings().add(this);
}
// default constructor, getter and setter here
}
5.3 A类
@NodeEntity
public class ClassA extends Entity {
private String name;
@Relationship(type = "CONTAINS")
private List<ClassC> classCs = new ArrayList<>();
@Relationship(type = "MAPS_TO")
private List<ClassB> classBs = new ArrayList<>();
// default constructor, getter and setter here
}
@NodeEntity
public class ClassB extends Entity {
private String name;
@Relationship(type = "MAPS_TO", direction = Relationship.INCOMING)
private List<ClassA> classAs = new ArrayList<>();
@Relationship(type = "CONTAINS")
private List<ClassD> classDs = new ArrayList<>();
// default constructor, getter and setter here
}
5.5 C类
@NodeEntity
public class ClassC extends Entity {
private String name;
@Relationship(type = "CONTAINS", direction = Relationship.INCOMING)
private ClassA classA;
@Relationship(type = "MAPS_TO")
private List<CDMapping> cdMappings = new ArrayList<>();
// default constructor, getter and setter here
}
5.6 D类
@NodeEntity
public class ClassD extends Entity {
@Relationship(type = "CONTAINS", direction = Relationship.INCOMING)
private ClassB classB;
@Relationship(type = "MAPS_TO", direction = Relationship.INCOMING)
private List<CDMapping> cdMappings = new ArrayList<>();
// default constructor, getter and setter here
}
更新
@Repository
public interface CDMappingDAO extends Neo4jRepository<CDMapping, Long> {
@Query("MATCH (classC:ClassC)-[relationship:MAPS_TO]-(classD:ClassD) WHERE id(classC)={classCId} AND id(classD)={classDId} RETURN classC, relationship, classD;")
CDMapping getRelationshipByClassCAndClassD(@Param("classCId") Long classCId, @Param("classDId") Long classDId);
}
5.8等级ADAO/ClassCDAO/ClassDDAO
@Repository
public interface ClassADAO extends Neo4jRepository<ClassA, Long> {
}
除了第一个
Neo4jRepository
键入
ClassCDAO
ClassDDAO
@Repository
public interface ClassBDAO extends Neo4jRepository<ClassB, Long> {
@Query("MATCH (classC:ClassC)<-[:CONTAINS]-(:ClassA)-[:MAPS_TO]->(classB:ClassB) WHERE id(classC)={classCId} RETURN classB;")
List<ClassB> findClassBSelection(@Param("classCId") Long classCId);
}