Java Hibernate InheritanceType.JOINED条件投影和

我正在尝试使用Hibernate继承对来自多个子类的simular表上的值求和

在我的父类上使用“@heritance（strategy=InheritanceType.JOINED）”，并有多个子类扩展它。我的问题是，当我使用带有“Projections.sum”的条件来获得结果时，Hibernate执行了一个有趣的连接

就好像hibernate获取第一个匹配结果并对其进行求和一样——忽略其余部分，我甚至不确定这是否可以完成

希望我下面的代码能澄清我的问题

动物-父类

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "animals")
public class Animals extends BaseObject{

    private Long animalId;
    private Long weight;

@Entity
@Table(name = "cats")
@PrimaryKeyJoinColumn(name="animal_id")
public class Cats extends Animals{

    private Long offspring;
    private String color;

@Entity
@Table(name = "dogs")
@PrimaryKeyJoinColumn(name="animal_id")
public class Dogs extends Animals{

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "birds")
@PrimaryKeyJoinColumn(name="animal_id")
public class Birds extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "fish")
@PrimaryKeyJoinColumn(name="animal_id")
public class Fish extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

猫-儿童班

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "animals")
public class Animals extends BaseObject{

    private Long animalId;
    private Long weight;

@Entity
@Table(name = "cats")
@PrimaryKeyJoinColumn(name="animal_id")
public class Cats extends Animals{

    private Long offspring;
    private String color;

@Entity
@Table(name = "dogs")
@PrimaryKeyJoinColumn(name="animal_id")
public class Dogs extends Animals{

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "birds")
@PrimaryKeyJoinColumn(name="animal_id")
public class Birds extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "fish")
@PrimaryKeyJoinColumn(name="animal_id")
public class Fish extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

狗-儿童班

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "animals")
public class Animals extends BaseObject{

    private Long animalId;
    private Long weight;

@Entity
@Table(name = "cats")
@PrimaryKeyJoinColumn(name="animal_id")
public class Cats extends Animals{

    private Long offspring;
    private String color;

@Entity
@Table(name = "dogs")
@PrimaryKeyJoinColumn(name="animal_id")
public class Dogs extends Animals{

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "birds")
@PrimaryKeyJoinColumn(name="animal_id")
public class Birds extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "fish")
@PrimaryKeyJoinColumn(name="animal_id")
public class Fish extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

鸟类-儿童班

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "animals")
public class Animals extends BaseObject{

    private Long animalId;
    private Long weight;

@Entity
@Table(name = "cats")
@PrimaryKeyJoinColumn(name="animal_id")
public class Cats extends Animals{

    private Long offspring;
    private String color;

@Entity
@Table(name = "dogs")
@PrimaryKeyJoinColumn(name="animal_id")
public class Dogs extends Animals{

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "birds")
@PrimaryKeyJoinColumn(name="animal_id")
public class Birds extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "fish")
@PrimaryKeyJoinColumn(name="animal_id")
public class Fish extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

鱼-子类

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "animals")
public class Animals extends BaseObject{

    private Long animalId;
    private Long weight;

@Entity
@Table(name = "cats")
@PrimaryKeyJoinColumn(name="animal_id")
public class Cats extends Animals{

    private Long offspring;
    private String color;

@Entity
@Table(name = "dogs")
@PrimaryKeyJoinColumn(name="animal_id")
public class Dogs extends Animals{

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "birds")
@PrimaryKeyJoinColumn(name="animal_id")
public class Birds extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

@Entity
@Table(name = "fish")
@PrimaryKeyJoinColumn(name="animal_id")
public class Fish extends Animals {

    private Long offspring;
    private String color;
    private int eggsLayed;

条件查询

    ProjectionList projList = Projections.projectionList()
            .add(Projections.sum("eggsLayed"));

    Criteria crit = getSession()
            .createCriteria(Animals.class)
            .setProjection(projList);

运行查询时的相关SQL输出：

Hibernate: 
    select
        sum(this_3_.eggs_layed) as y0_ 
    from
        animals this_ 
    left outer join
        cats this_1_ 
            on this_.animal_id=this_1_.animal_id 
    left outer join
        dogs this_2_ 
            on this_.animal_id=this_2_.animal_id 
    left outer join
        birds this_3_ 
            on this_.animal_id=this_3_.animal_id 
    left outer join
        fish this_4_ 
            on this_.animal_id=this_4_.animal_id

任何反馈都将不胜感激