从表中删除行抛出 ConstraintViolationException

Question

当我想从数据库中删除产品时遇到问题，删除它，它应该从包含该产品的所有订单中删除。 但是当我尝试这样做时，这是我得到的错误：

"error_message": "Request processing failed; nested exception is org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [fkbjvki7e3gm7vrphs73g4x7d2g]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement"

这是我的订单 class：

@Entity
@Table(name="orders")
public class Order{
    private @Id
    @GeneratedValue
    Long id;
    @OneToMany(mappedBy = "order", cascade = CascadeType.ALL,orphanRemoval = true)
    private List<ProductOrderDetails> orderedProducts = new ArrayList<>();
public void addProduct(Product product, int quantity) {
        ProductOrderDetails orderedProduct = new ProductOrderDetails(this,product,quantity);
        orderedProducts.add(orderedProduct);
        product.getProductOrderDetails().add(orderedProduct);
        totalOrderPrice+=product.getPrice()*quantity;
    }

    public void removeProduct(Product product,int quantity) {
        ProductOrderDetails orderedProduct = new ProductOrderDetails( this, product,0);
        product.getProductOrderDetails().remove(orderedProduct);
        orderedProducts.remove(orderedProduct);
        orderedProduct.setOrder(null);
        orderedProduct.setProduct(null);
        totalOrderPrice-=product.getPrice()*quantity;
    }
}

这是我的产品 class

@Entity
@Table
public class Product {
    private @Id
    @GeneratedValue
    Long id;
    private String name;
    @OneToMany(mappedBy = "order", cascade = CascadeType.MERGE,orphanRemoval = true)
    private List<ProductOrderDetails> productOrderDetails = new ArrayList<>();
}

产品订单ID

@Embeddable
public class ProdOrderId implements Serializable {
    @Column(name = "order_id")
    private Long orderId;

    @Column(name = "product_id")
    private Long productId;
}

多对多列的产品和订单

@Entity
@Table
public class ProductOrderDetails implements Serializable{

    @EmbeddedId
    @JsonIgnore
    private ProdOrderId id;


    @ManyToOne
    @MapsId("orderId")
    @JsonIgnore
    Order order;

    @ManyToOne
    @MapsId("productId")
    Product product;

    private int quantity;
}

这是我的 controller 方法

@DeleteMapping("/{id}")
    ResponseEntity<?> deleteProduct(@PathVariable Long id)
    {
        repository.deleteById(id);
        return ResponseEntity.noContent().build();
    }

Answer 1

我不认为这是在做你认为它在做的事情：

ProductOrderDetails orderedProduct = new ProductOrderDetails( this, product,0);
product.getProductOrderDetails().remove(orderedProduct);

如果您调试代码或检查remove的返回值，您会发现它返回false ，这意味着没有任何内容被删除。

您只是在创建一个新的ProductOrderDetails ，然后尝试将其从product.getProductOrderDetails()中删除，但其中不存在。 您需要找到要从该集合中删除的正确元素。