Hibernate/JPA单向OneToMany在源表中的常量值上具有连接条件

Question

我想使用Hibernate注释来表示使用联接的单向一对多关系。我希望在连接上添加一个条件，这样它只在源表中的列（“一”）等于一个常量值时才发生。例如。

SELECT *
FROM buildings b
LEFT JOIN building_floors bf on bf.building_id = b.id AND b.type = 'OFFICE'

@Entity
@Table(name = "buildings")
public class Building {

    @Id
    @Column(name = "id")
    private int id;

    @Column(name = "type")
    private String type;

    @OneToMany(mappedBy = "buildingId",
            fetch = FetchType.EAGER,
            cascade = {CascadeType.ALL},
            orphanRemoval = true)
    @Fetch(FetchMode.JOIN)
    // buildings.type = 'OFFICE'   ????
    private Set<BuildingFloors> buildingFloors;

    // getters/setters
}

@Entity
@Table(name = "building_floors")
public class BuildingFloor {

    @Id
    @Column(name = "building_id")
    private int buildingId;

    @Id
    @Column(name = "floor_id")
    private int floorId;

    @Column(name = "description")
    private String description;

    // getters/setters
}

@JoinColumns({
        @JoinColumn(name = "building_id", referencedColumnName = "id"),
        @JoinColumn(name = "'OFFICE'", referencedColumnName = "type")
})

这不起作用，因为我得到了以下错误（为清楚起见进行了简化）:SQL语句“select*FROM buildings b JOIN building_floresbf on bf.building_id=b.id AND bf.'office'=b.type”语法错误

@JoinColumns({
        @JoinColumn(name = "building_id", referencedColumnName = "id"),
        @JoinColumn(name = "buildings.type", referencedColumnName = "'OFFICE'")
})

这不起作用，因为在使用单向OneToMany关系时，referencedColumnName来自源表。因此，我得到错误:org.hibernate.mappingException：无法在建筑物中找到逻辑名称为“office”的列

提前道谢！

Answer 1

为什么不用继承呢？（我和JPA一起使用，我从来没有直接使用hibernate）

@Entity
@Inheritance
@Table(name = "buildings")
@DiscriminatorColumn(name="type")
public class Building {

    @Id
    @Column(name = "id")
    private int id;

    @Column(name = "type")
    private String type;
}

和：

@Entity
@DiscriminatorValue("OFFICE")
public class Office extends Building {
    @OneToMany(mappedBy = "buildingId",
        fetch = FetchType.EAGER,
        cascade = {CascadeType.ALL},
        orphanRemoval = true)
    private Set<BuildingFloors> buildingFloors;
}