目前由于Neo4j OGM中的GitHub问题https://github.com/neo4j/neo4j-ogm/issues/215，我必须使用以下解决方法将org.neo4j.ogm.session.Session.query结果返回@QueryResult转换为此{{1}的列表}}：
Cypher查询示例：
@QueryResult解决方法：
MATCH (parentD)-[:CONTAINS]->(childD:Decision)-[ru:CREATED_BY]->(u:User) WHERE id(parentD) = {decisionId} OPTIONAL MATCH (childD)<-[:VOTED_FOR]-(vg:VoteGroup)-[:VOTED_ON]->(c:Criterion) WHERE id(c) IN {criteriaIds} WITH childD, ru, u, vg.avgVotesWeight as weight OPTIONAL MATCH (childD)<-[:SET_FOR]->(sortValue375:Value)-[:SET_ON]->(sortCharacteristic375:Characteristic) WHERE id(sortCharacteristic375) = 375 RETURN childD AS decision, ru, u, toFloat(sum(weight)) as weight, sortValue375 ORDER BY weight DESC, sortValue375.value DESC, childD.createDate DESC SKIP 0 LIMIT 1000
现在而不是@QueryResult
public class WeightedDecision {
private Decision decision;
private Double weight;
...
}
Result queryResult = session.query(characteristicCypher, parameters);
List<WeightedDecision> weightedDecisions = new ArrayList<>();
for (Map<String, Object> result : queryResult) {
WeightedDecision weightedDecision = new WeightedDecision();
weightedDecision.setDecision((Decision) result.get("decision"));
weightedDecision.setWeight((double) result.get("weight"));
weightedDecisions.add(weightedDecision);
}
我必须返回List<WeightedDecision>
怎么做？请帮我更改代码，以便将queryResult转换为Page<WeightedDecision>
另外，如何在此逻辑中提供Page<WeightedDecision>？
答案 0 :(得分：1)
参考这篇文章Conversion of List to Page in Spring，您可以使用Page实现从结果列表到org.springframework.data.domain.PageImpl实例的映射。在您的情况下，将结果映射到List后，您可以执行以下操作：
PageRequest pageable = new PageRequest(0, 2);
Page<WeightedDecision> page = new PageImpl<>(weightedDecisions, pageable, weightedDecisions.size());
背景：据我所知，目前无法在SDN（Paging and sorting in Spring Data Neo4j 4）中对自定义查询使用Pageable。因此，您必须自己进行映射。
你的第二个问题是计数逻辑。在我看来，您必须再次调用您的查询，具体取决于您想要计算的内容。例如，计算childD个节点：
MATCH (parentD)-[:CONTAINS]->(childD:Decision)-[ru:CREATED_BY]->(u:User) WHERE id(parentD) = {decisionId}
OPTIONAL MATCH (childD)<-[:VOTED_FOR]-(vg:VoteGroup)-[:VOTED_ON]->(c:Criterion) WHERE id(c) IN {criteriaIds} WITH childD, ru, u, vg.avgVotesWeight as weight
OPTIONAL MATCH (childD)<-[:SET_FOR]->(sortValue375:Value)-[:SET_ON]->(sortCharacteristic375:Characteristic) WHERE id(sortCharacteristic375) = 375 RETURN count(childD) AS result;