JPA 2.1谓词，子实体的标准

Question

我使用JPA2.1、Spring数据和CriteriaBuilder、谓词对我的JPA实体进行查询。我有一个父实体InvoiceSummary，它与名为ShipmentStop的子实体有@OneToMany关系。我想在子实体ShipmentStop上设置条件，但不确定如何进行。我还希望能够同时在父表和子表上设置条件。有没有一种方法可以使用谓词来实现这一点？例如，我想按子实体的departureDate、isFirstPick和isLastDrop字段进行搜索。除了子实体搜索条件外，我还可能希望搜索父实体dueDate。下面是我的实体代码和我如何生成查询的代码。

这是我的标准生成器

    public Specification<T> isBetween(List<RangeFilter> filters) {
    return new Specification<T>() {
        @Override
        public Predicate toPredicate(Root<T> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
            List<Predicate> predicates = new ArrayList<>();
            for (RangeFilter filter: filters) {
                if (!filter.getStartValue().isEmpty()) {
                    mapFilterCriteria(root, criteriaBuilder, predicates, filter);
                }
            }
            return criteriaBuilder.and(predicates.toArray(new Predicate[]{}));
        }
    };
}

private void mapFilterCriteria(Root<T> root, CriteriaBuilder criteriaBuilder, List<Predicate> predicates, RangeFilter filter) {
    if(root.get(filter.getName()).getJavaType().getName().equals("java.time.LocalDateTime")) {
        predicates.add(criteriaBuilder.greaterThanOrEqualTo(root.get(filter.getName()), convertStringToLocalDate(filter.getStartValue())));
        predicates.add(criteriaBuilder.lessThanOrEqualTo(root.get(filter.getName()), convertStringToLocalDate(filter.getEndValue())));
    }
    else {
        predicates.add(criteriaBuilder.greaterThanOrEqualTo(root.get(filter.getName()), filter.getStartValue()));
        predicates.add(criteriaBuilder.lessThanOrEqualTo(root.get(filter.getName()), filter.getEndValue()));
    }
}

这是我的父实体公共类发票{

@Id
@Column(name = "shipment_id")
private int shipmentId;

@Column(name = "customer_id")
private int customerId;

@Column(name = "invoice_date")
@JsonFormat(pattern = "MM/dd/yyyy HH:mm")
private LocalDateTime invoiceDate;

@Column(name = "due_date")
private String dueDate;

@OneToMany(mappedBy = "invoice",
        cascade = CascadeType.ALL,
        orphanRemoval = true)
private List<ShipmentStop> shipmentStops;

这是我的子实体

@Entity
@Table(name = "shipment_stops")
public class ShipmentStop {

@Id
@Column(name = "shipment_stop_id")
private int shipmentStopId;

@Column(name = "shipment_id")
private int shipmentId;

@ManyToOne
@JoinColumn(name = "stop_type_id", referencedColumnName = "stop_type_id")
private ShipmentStopType shipmentStopType;

@Column(name = "is_firstpick")
private boolean isFirstPick;

@Column(name = "is_lastdrop")
private boolean isLastDrop;

@Column(name = "depart_date")
@JsonFormat(pattern = "MM/dd/yyyy HH:mm:ss")
private LocalDateTime departDate;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "shipment_id", insertable = false, updatable = false)
private Invoice invoice;

Answer 1

您可以尝试子查询，例如：

Subquery<?> subQuery = query.subquery(ShipmentStop.class);
Root<?> rootChild = subQuery.from(ShipmentStop.class);
subQuery
       .select(rootChild.join("shipmentId"))
                .where(criteriaBuilder.and(predicate1, predicate2)); // your predicates on children

root.get("shipmentId").in(subQuery);