@Entity
public class DocumentConsolidated {
@Id private UUID id;
@OneToOne(fetch = FetchType.EAGER, optional = false, cascade = CascadeType.ALL)
@JoinColumn(name = "metadata_id")
private DocumentMetadata documentMetadata;
@OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true, mappedBy = "documentConsolidated")
private DocumentConfiguration documentConfiguration;
}
@Entity
public class DocumentConfiguration {
@Id private UUID id;
@OneToOne(fetch = FetchType.LAZY)
@MapsId
private DocumentConsolidated documentConsolidated;
}
// Service code:
QDocumentConsolidated qDoc = QDocumentConsolidated.documentConsolidated;
(JPQLQueryFactory) queryFactory
.select(Projections.fields(qDoc, /*qDoc.id, */qDoc.documentConfiguration, qDoc.documentMetadata))
.from(qDoc)
.innerJoin(qDoc.documentConfiguration)
.fetch();
这只有两种方式：
id存在，documentconfiguration为空ID为空，DocumentConfiguration存在我已经检查过的内容：当我在Postgres客户机中运行Hibernate查询时，它总是带来documentconfiguration字段。Botdocumentmetadata在这两种情况下都存在。
问题没有得到解决，但我通过从混合中删除投影来解决它：
// Service code:
QDocumentConsolidated qDoc = QDocumentConsolidated.documentConsolidated;
QDocumentConfiguration qCfg = qDoc.documentConfiguration;
QDocumentMetadata qMeta = qDoc.documentMetadata;
return queryFactory
.select(qDoc, qCfg, qMeta) // <-- get rid of Projections
.from(qDoc)
.innerJoin(qCfg) // <-- manual join on Lazy entity (qMeta is auto-joined)
.fetch().stream()
.map(tuple -> { // <-- entity creation, similar with Projections.bean()
DocumentConsolidated documentConsolidated = Objects.requireNonNull(tuple.get(qDoc));
documentConsolidated.setDocumentMetadata(tuple.get(qMeta));
documentConsolidated.setDocumentConfiguration(tuple.get(qCfg));
return documentConsolidated;
})
.collect(Collectors.toList());
