Question

在我的Neo4j 3.0.1和SDN 4.1.1.RELEASE项目中，我有以下实体：

@NodeEntity
public class CriterionGroup extends Authorable {

    private final static String DEFINED_BY = "DEFINED_BY";
    private final static String CONTAINS = "CONTAINS";

    private String name;

    private String description;

    @Relationship(type = DEFINED_BY, direction = Relationship.OUTGOING)
    private Decision owner;

    @Relationship(type = CONTAINS, direction = Relationship.OUTGOING)
    private Set<Criterion> criteria = new HashSet<>();
....

@NodeEntity
public class Criterion extends Authorable {

    private final static String CONTAINS = "CONTAINS";
    private final static String DEFINED_BY = "DEFINED_BY";

    private String name;

    private String description;

    @Relationship(type = CONTAINS, direction = Relationship.INCOMING)
    private CriterionGroup group;

    @Relationship(type = DEFINED_BY, direction = Relationship.OUTGOING)
    private Decision owner;
....


@NodeEntity
public class Decision extends Commentable {

    private final static String CONTAINS = "CONTAINS";
    private final static String DEFINED_BY = "DEFINED_BY";
    private final static String VOTED_FOR = "VOTED_FOR";

    private String name;

    @Relationship(type = CONTAINS, direction = Relationship.INCOMING)
    private Set<Decision> parentDecisions = new HashSet<>();

    @Relationship(type = CONTAINS, direction = Relationship.OUTGOING)
    private Set<Decision> childDecisions = new HashSet<>();

    @Relationship(type = DEFINED_BY, direction = Relationship.INCOMING)
    private Set<CriterionGroup> criterionGroups = new HashSet<>();

    @Relationship(type = DEFINED_BY, direction = Relationship.INCOMING)
    private Set<Criterion> criteria = new HashSet<>();
....

在我的测试中，我尝试使用以下存储库方法删除CriterionGroup：

@Query("MATCH ()-[r]-(cg:CriterionGroup) WHERE id(cg) = {criterionGroupId} DELETE cg, r")
void deleteCriterionGroup(@Param("criterionGroupId") Long criterionGroupId);

然后我试图通过id

获取此CriterionGroup

criterionGroupRepository.findOne(id);

并返回NULL。到目前为止一切都很好。

之后，我正在尝试从已删除的Criterion中的CriterionGroup获取组对象，并返回..已删除CriterionGroup

criterionRepository.findOne(criterion.getId()).getGroup()

我做错了什么？一切都在SDN 3.4.4.RELEASE和Neo4j 2.3.3上工作正常，但Neo4j 3.0.1 SDN 4.1.1.RELEASE由于我的知识有限，我有很多意想不到的情况。

此外，在一个实体中有以下关系定义是否可以（我已删除enforceTargetType）

@Relationship(type = CONTAINS, direction = Relationship.INCOMING)
private Set<Decision> parentDecisions = new HashSet<>();

@Relationship(type = CONTAINS, direction = Relationship.OUTGOING)
private Set<Decision> childDecisions = new HashSet<>();

他们有不同的指示。

Answer 1

据我所知，您重新出现此CriterionGroup是因为您通过自定义查询删除了它，从而绕过了OGM。图表知道您的更改，但OGM的映射上下文不知道。解决方案是在使用Session.detachEntity(id)通过自定义查询删除此实体后，从会话中注销该实体，或者使用session.clear()刷新整个会话。

是的，可以使用CONTAINS关系定义，请记住，对于标记为INCOMING的任何关系，如果parentDecisions存在，则必须为@Relationship(type = CONTAINS, direction = Relationship.INCOMING)注释访问者，变更器和属性}

更新：还要确保您的对象模型与您通过自定义查询删除的内容保持同步。即如果您通过自定义查询删除CriterionGroup，您还应该更新对象模型以反映这一点criterion.group=null。或者，使用session.clear()完全清除会话并重新加载所有相关实体。

Neo4j 3.0.1 SDN 4.1.1.RELEASE幻像节点

1 个答案: