Question

在我的Neo4j / SDN4项目中，我有一个以下节点实体：

@NodeEntity
public class Nomination extends Commentable {

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

    private String name;

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

...

}

我需要实现一个Cypher查询，该查询将尝试通过精确的相关标准集合（按标准ID）查找Nomination。

现在我有以下查询：

MATCH (n:Nomination)-[:CONTAINS]->(c:Criterion) WHERE id(n) = {nominationId} AND id(c) IN {criterionIds} RETURN n

但这还不够，因为Nomination可以包含{criterionIds}中提供的较少条件，但我需要检查完全匹配（条件顺序无关紧要）

如何重新实现此查询才能执行此操作？

Answer 1

使用COLLECT然后使用ALL功能。

https://neo4j.com/docs/developer-manual/current/cypher/functions/predicates/#functions-all

MATCH (n:Nomination)-[:CONTAINS]->(c:Criterion) 
WHERE id(n) = {nominationId}
WITH n,COLLECT(id(c)) AS foundCritIds
WHERE ALL (id IN {criterionIds} WHERE id in foundCritIds) 
RETURN n

Answer 2

这是另一种方法，您可能希望每个人都能查看最适合您的方法：

MATCH (c:Criterion)
WHERE id(c) in {criterionIds}
WITH COLLECT(c) as criterion
WITH criterion, head(criterion) as firstC
MATCH (firstC)<-[:CONTAINS]-(n:Nomination)
WHERE SIZE((n)-[:CONTAINS]->(:Criterion)) = SIZE(criterion)
 AND ALL(crit in criterion[1..] WHERE (n)-[:CONTAINS]->(crit))    
RETURN n

Neo4j Cypher通过关联节点（ID）的精确集合查找实体

2 个答案: