Java 使用Group By和Having子句为多对多关系编写联接查询

我需要返回与订单关联的超过2个产品的每个订单。订单和产品具有多对多关系，如下所示

@Data
@Entity
@Table(name = "orders")
@JsonInclude(NON_NULL)
public class Order implements Serializable {

    public static final int PRECISION = 2;

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @JsonIgnore
    private String orderId;

    . . .  Other fields . . . .

    @ManyToMany(fetch = EAGER, cascade = ALL)
    @JoinTable(
            name = "order_product",
            joinColumns = @JoinColumn(name = "order_id", updatable = false, nullable = false),
            inverseJoinColumns = @JoinColumn(name = "product_id", updatable = false, nullable = false)
    )
    private List<Product> products = new ArrayList<>();
}

我的SQL查询应该是

SELECT o.order_id, p.product_id from Orders o join 
    OrderProduct op on o.order_id = op.order_id join Product p on   
    op.product_id = p.product_id group by o.order_id, p.product_id having    
    (p.product_id) > 2

我写这个查询的最佳尝试

   @Query("SELECT o from Order o JOIN o.products where o.id = :id GROUP BY o HAVING (o.product) > 2")
  List<Order> findOrderWithMultipleProducts();

控制器仅直接调用此函数。所需的JSON负载如下所示

{
         "orderId": "order_id",
         "products": [
             {
                 "productId": "product_id_1",
             },
             {
                  "productId": "product_id_2",
             },
             {
                  "productId": "product_id_3",
             }
         ]
     }

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查询的where子句为：id，带有：字符。所以hibernate需要一个参数

  @Query("SELECT o from Order o JOIN o.products where o.id = :id GROUP BY o HAVING (o.product) > 2")
  List<Order> findOrderWithMultipleProducts();

假设id是字符串类型

使用@Query注释的另一种方法是在方法中传递参数，并更改：id以反映参数序列

@Query("SELECT o from Order o JOIN o.products where o.id = ?1 GROUP BY o HAVING (o.product) > 2")
List<Order> findOrderWithMultipleProducts(int id);

@Query（“从订单中选择o加入o.products，其中o.id=？1个组，o拥有（o.product）>2”）
列出具有多个产品（int id）的FindOrders；

更多详细信息可在此处找到：

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我不知道这个问题的答案，但OP在加入某个领域时不需要“where”子句。

  @Query("SELECT o from Order o JOIN o.products where o.id = :id GROUP BY o HAVING (o.product) > 2")
  List<Order> findOrderWithMultipleProducts();

SQLQuery query = SELECT o from Order o JOIN o.products where o.id = :id GROUP BY o HAVING (o.product) > 2
query.setString("id",ValueOfId);

@Query("SELECT o from Order o JOIN o.products where o.id = ?1 GROUP BY o HAVING (o.product) > 2")
List<Order> findOrderWithMultipleProducts(int id);