Spring JPA查询以获取具有计数条件的数据

Question

I have an Order Entity that has many Review Entities. Order has many OrderItem entities that's also has many Review Entities. So User can enter reviews for specific Order as common review or specific Order Item as item review.

Now I want to List the Orders with reviews available and Order with No reviews. For this I have to check Order || OrderItem has reviews in Reviews Table simultaneously. I think count query with Join clause to be performed. Please solve this problem.

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

To find those reviews that are associated with orders or order-items, you can query on ReviewDO object by placing a ReviewRepository as is shown below:-

@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();

}

Please check the test case given below matching to your requirements or not

import static 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));
    }
}