如何在 spring 数据查询中获取 instanceof 对象

Question

我有一个Itemclass

@Getter
@Setter
@Entity
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class Item {
    @Id 
    private Long id;
    private String name;
}

而这两个 class 是 Item

的子class

@Getter
@Setter
@Entity
public class RawMaterial extends Item {
    private String supplier;
}

@Getter
@Setter
@Entity
public class Product extends Item {
    private BigDecimal salePrice;
}

我还有一个 Inventory class 字段 Item

@Getter
@Setter
@Entity
public class Inventory {
    @Id 
    private Long id;

    @ManyToOne 
    private Item item;
}

我的问题是如何获得 item 字段的实例。与 dtype 有什么关系吗？

public interface InventoryDao extends JpaRepository<Inventory,Long> {

    @Query("FROM Inventory WHERE item instance of ?1")
    public List<Inventory> getInventoryByItem(Class klazz);

}

我需要做一些类似的事情

List<Inventory> list = getInventoryByItem(Product.class);

Answer 1

我自己解决了

public interface InventoryDao extends JpaRepository<Inventory,Long> {

    @Query("FROM Inventory WHERE TYPE(item.class) = ?1")
    public List<Inventory> getInventoryByItem(Class<? extends Item> klazz);

}

如何在 spring 数据查询中获取 instanceof 对象

How do i get insanceof object in spring data query

java

spring

jpa

instanceof

spring-data