子类外键在数据库表中为空

Question

我试图将作为主键的父类ID保存为子类中的外键，但它始终为null。 如果外键与父表中的现有记录不匹配，则DB Schema正确创建了我尝试手动添加的外键约束，这会导致约束错误。

父类：

package com.canaldigital.tsi.order.domain;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Optional;

import javax.persistence.CascadeType;
import javax.persistence.CollectionTable;
import javax.persistence.Column;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.SequenceGenerator;

@Entity(name = "Order_Product")
public class NewCustomerProduct extends TrackedSubEntity.Many<Order> {

    @Id
    @SequenceGenerator(name = "ProductId_SEQ", sequenceName = "ProductId_SEQ", allocationSize = 1)
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "ProductId_SEQ")
    private Long id;

    @ElementCollection(fetch = FetchType.LAZY)
    @CollectionTable(name = "Product_Offer", joinColumns = @JoinColumn(name = "OrderProduct_Id") )
    @Column(name = "Offer")
    private List<String> offerIds;

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "prefDef")
    private UpgradeDowngrade upgradeDowngrade;

    protected NewCustomerProduct() {
    }

    public NewCustomerProduct(List<String> offerIds, List<String> serialNumbers, UpgradeDowngrade upgradeDowngrade) {

        this.offerIds = offerIds;
        this.upgradeDowngrade = upgradeDowngrade;
    }

    private NewCustomerProduct(Builder builder) {

        offerIds = builder.offerIds;
        upgradeDowngrade = builder.upgradeDowngrade;
    }

    public static Builder create() {
        return new Builder();
    }

    public Builder copy() {
        return new Builder(this);
    }

    public List<String> getOfferIds() {
        return Collections.unmodifiableList(offerIds);
    }

    public Optional<UpgradeDowngrade> getUpgradeDowngrade() {
        return Optional.ofNullable(upgradeDowngrade);
    }

    public void setUpgradeDowngrade(UpgradeDowngrade upgradeDowngrade) {
        this.upgradeDowngrade = upgradeDowngrade;
    }

    public static final class Builder {
        private List<String> serialNumbers = new ArrayList<>();
        private List<String> offerIds = new ArrayList<>();
        private UpgradeDowngrade upgradeDowngrade;

        private Builder() {
        }

        private Builder(NewCustomerProduct newCustomerProduct) {
            offerIds = new ArrayList<>(newCustomerProduct.offerIds);
            upgradeDowngrade = newCustomerProduct.upgradeDowngrade;
        }

        public Builder withOfferId(String offerId) {
            this.offerIds.add(offerId);
            return this;
        }

        public Builder withSerialNumbers(String serialNumbers) {
            this.serialNumbers.add(serialNumbers);
            return this;
        }

        public NewCustomerProduct build() {
            return new NewCustomerProduct(this);
        }

        public Builder withUpgradeDowngrade(UpgradeDowngrade upgradeDowngrade) {
            this.upgradeDowngrade = upgradeDowngrade;
            return this;
        }
    }
}

儿童班：

package com.canaldigital.tsi.order.domain;

import java.time.LocalDate;
import java.util.Optional;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;

@Entity
@Table(name = "Upgrade_Downgrade_Customer_Product")
public class UpgradeDowngrade {

    @Id
    @SequenceGenerator(name = "UpgradeDowngradeId_SEQ", sequenceName = "UpgradeDowngradeId_SEQ", allocationSize = 1)
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "UpgradeDowngradeId_SEQ")
    private Long id;

    @Column(name = "Old_Commercial_Product_Id")
    private Integer oldCommercialProductId;

    @Column(name = "Upgrade")
    private Boolean upgrade;

    @Column(name = "Schedule_Date")
    private LocalDate scheduleDate;

    @OneToOne
    @JoinColumn(name = "OrderProduct_Id")
    private NewCustomerProduct prefDef;

    public UpgradeDowngrade(Integer oldCommercialProductId, boolean upgrade, LocalDate scheduleDate) {

        this.oldCommercialProductId = oldCommercialProductId;
        this.upgrade = upgrade;
        this.scheduleDate = scheduleDate;        
    }

    public UpgradeDowngrade() {
        // Required by Jackson
    }

    public Optional<Integer> getOldCommercialProductId() {
        return Optional.ofNullable(oldCommercialProductId);
    }

    public Optional<Boolean> isUpgrade() {
        return Optional.ofNullable(upgrade);
    }

    public Optional<LocalDate> getScheduleDate() {
        return Optional.ofNullable(scheduleDate);
    }

}