How to perform delete operation in classes which consists one to many relationship

Question

This is my product Entity
   
 @Entity
    public class Product {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private int id;
    
        @NotNull
        private String name;
    
        private String cancellable;
        private String returnable;
        @NotNull
        private String brand;
        private boolean active;
        @JsonIgnore
        @OneToMany(mappedBy = "product",cascade = CascadeType.ALL)
        private Set<ProductVariation> productVariationSet;
    }

    
This is Product Variant Entity

    @Entity
    public class ProductVariation {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private int id;
    
        private String ProductName;
    
        @NotNull
        private int quantityavailable;
        @NotNull
        private int price;
    
    
        private String details;
   
    
        @JsonIgnore
        @ManyToOne
        @JoinColumn(name = "product_id")
        private Product product;
    
     }
    
    
    

when i am tring to delete products by ID i am getting error like

java.sql.SQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint fails ( mywebapp . product_variation , CONSTRAINT FKpryf02se86hpv5v7xn5afye4v FOREIGN KEY ( product_id ) REFERENCES product ( id ))

How i can correct this error and delete product so its all variant is also delete.

Answer 1

The cascade operation in Product class as you defined it deletes the product's variants automatically. Just remove @JsonIgnore from field 'private Set productVariationSet' and from field 'private Product product'.