Question

我有一个具有许多审阅实体的订单实体。订单具有许多OrderItem实体，也具有许多审阅实体。因此，用户可以将特定订单的评论输入为普通评论，也可以将特定订单商品输入为商品评论。

现在，我要列出具有可用评论的订单和没有评论的订单。为此，我必须检查订单|| OrderItem在评论表中同时具有评论。我认为要执行带有Join子句的计数查询。请解决这个问题。

OrderDO.java

@Table(name = "ORDER")
public class OrderDO  implements Serializable{

    @Column(name = "ORDER_NUMBER", nullable = false)
    private String orderNumber; 

    @OneToMany(cascade = CascadeType.ALL, mappedBy="order")
    private Set<ReviewDO> reviews = new HashSet<>();
}

OrderItemDO.java

@Table(name = "ORDER_ITEM")
public class OrderItemDO implements Serializable{   

    @Column(name = "PRODUCT_NAME",nullable = false)
    private String name;

    @OneToMany(cascade = CascadeType.ALL, mappedBy="item")
    private Set<ReviewDO> reviews = new HashSet<>();
}

ReviewDO.java

@Table(name = "REVIEW")
public class ReviewDO implements Serializable {

    @Column(name = "RATING")
    private double rating;

    @Column(name = "REVIEW_TEXT")
    private String reviewText;

    @ManyToOne()
    @JoinColumn(name = "ITEM_ID", referencedColumnName="ID")
    private OrderItemDO item;

    @ManyToOne()
    @JoinColumn(name = "ORDER_ID", referencedColumnName="ID")
    private OrderDO order;
   }

OrderRepository.java

@Repository
public interface OrderRepository extends CrudRepository<OrderDO, Long>{

    @Query("select order from OrderDO order where order.orderNumber = ?1")
    public Optional<OrderDO> findByOrderNumber(String orderNumber);

}

Answer 1

要查找与订单或订单项相关的评论，可以通过放置ReviewDO来查询ReviewRepository对象，如下所示：-

@Repository
public interface ReviewRepository extends CrudRepository<ReviewDO, Long>{

    @Query(value = "SELECT r FROM ReviewDO r where r.item is not null or r.order is not null")
    List<ReviewDO> findAllByOrdersOrOrderItems();

}

请检查下面给出的测试用例是否符合您的要求

导入静态org.junit.Assert.assertEquals;

import java.util.List;
import java.util.stream.Collectors;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import com.raj.so.artefacts.OrderDO;
import com.raj.so.artefacts.OrderItemDO;
import com.raj.so.artefacts.OrderItemRepository;
import com.raj.so.artefacts.OrderRepository;
import com.raj.so.artefacts.ReviewDO;
import com.raj.so.artefacts.ReviewRepository;

@DataJpaTest
@RunWith(SpringRunner.class)
public class ReviewRepositoryTest {

    @Autowired
    private OrderRepository orderRepository;

    @Autowired
    private OrderItemRepository orderItemRepository;

    @Autowired
    private ReviewRepository reviewRepository;

    @Test
    public void testRepositoryFetch() {

        // creating 2 orders
        OrderDO orderDO1 = new OrderDO();
        orderDO1.setOrderNumber("1");
        orderRepository.save(orderDO1);
        OrderDO orderDO2 = new OrderDO();
        orderDO2.setOrderNumber("2");
        orderRepository.save(orderDO2);

        // creating an order item
        OrderItemDO orderItemDO1 = new OrderItemDO();
        orderItemDO1.setName("order item 1");
        orderItemRepository.save(orderItemDO1);

        // creating 2 reviews - one for order; other for item
        ReviewDO reviewDO1 = new ReviewDO();
        reviewDO1.setRating(5.0);
        reviewDO1.setReviewText("rate five");
        reviewDO1.setOrder(orderDO1);
        reviewRepository.save(reviewDO1);

        ReviewDO reviewDO2 = new ReviewDO();
        reviewDO2.setRating(4.0);
        reviewDO2.setReviewText("rate four");
        reviewDO2.setItem(orderItemDO1);
        reviewRepository.save(reviewDO2);

        // query all reviews associated to orders or items
        // returned review objects will have details about orders and items
        List<ReviewDO> reviews = reviewRepository.findAllByOrdersOrOrderItems();

        assertEquals(2, reviews.size());

        List<String> orderNumbers = reviews.stream().map(item -> {
            if (item.getOrder() != null) {
                return item.getOrder().getOrderNumber();
            } else {
                return null;
            }
        })
        .filter(item -> item != null)
        .collect(Collectors.toList());

        assertEquals("1", orderNumbers.get(0));

        List<String> orderItemNames = reviews.stream().map(item -> {
            if (item.getItem() != null) {
                return item.getItem().getName();
            } else {
                return null;
            }
        })
        .filter(item -> item != null)
        .collect(Collectors.toList());

        assertEquals("order item 1", orderItemNames.get(0));
    }
}

Spring JPA查询以获取具有计数条件的数据

1 个答案: