从表中删除行抛出 ConstraintViolationException

Question

Im having a problem when i want to delete the product from the database, deleting it, it should be removed from all the orders that contain that product. But when i try to do it this is the error i get:

"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"

This is my Order 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;
    }
}

This is my Product 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<>();
}

ProductOrderID

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

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

Many to many column of Products and Orders

@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;
}

This is my controller method

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

Answer 1

I don't think this is doing what you think it's doing:

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

If you debug your code or check the return value of remove you will find that it is returning false , which means nothing was removed.

You're just creating a new ProductOrderDetails and then trying to remove it from product.getProductOrderDetails() , but it doesn't exist in it. You need to find the right element to remove from that collection.