java - Hibernate查询转Sql查询

Question

我的产品实体如下所示:

@Entity
@Table(name = "order")

public class OrderEntity {

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Column(name = "order_id")
   private Long id;

   @ManyToMany(cascade = CascadeType.ALL)
   @JoinTable(
        name = "order_products",
        joinColumns = @JoinColumn(name = "order_id", referencedColumnName = "order_id"),
        inverseJoinColumns = @JoinColumn(name = "product_id", referencedColumnName = "id")
   )
   private Set<ProductEntity> products = new HashSet<>();
}

产品实体:

@Entity
@Table(name = "product")
public class ProductEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;

    @Column(unique = true)
    private String name;

    @ManyToMany(mappedBy = "products")
    private Set<OrderEntity> orders = new HashSet<>();
}

我想获得产品名称等于想要的值的所有订单。我编写了 sql 查询以从数据库中获取结果，但我无法为 Spring Data JPA 编写 hibernate 查询。

我对 postgreSQL 的查询如下所示:

SELECT o.order_id, op.product_id, p.name
  FROM public.order o
  INNER JOIN public.order_products op
    ON p.order_id = op.product_id
  INNER JOIN public.product p
    ON op.product_id = p.id
  WHERE p.name = 'Foo';

此查询返回订单 ID、product_id 和产品名称。这行得通。但是我不知道如何使用@Query 将这个问题写成spring query。

我的存储库中需要一个方法:

@Repository
public interface OrderRepository extends JpaRepository<OrderEntity, Long> {
    @Query("") <- place for my query in Hibernate sql
    List<OrderEntity> findAllByProductName(@Param("name") String name);
}

Answer 1

试试这个:(它返回完整的 OrderEntity 对象)

@Query("select  o from OrderEntity o join o.products prod where prod.name = :name")
List<OrderEntity> findAllByProductName(@Param("name") String name);

如果您需要获取产品的所有数据，请使用:....OrderEntity o join o.products... 在查询中而不是 OrderEntity o join o.products