CODEWITHSUNDEEP
javasqljpa
mariusz
mariusz

Reputation: 167

Could not execute SQL statement

While writing my application I came across a problem with executting SQL statement. I tried to look for a solution on the net, but none of the found helped and I still do not know how to deal with an error I get. Here is exception I get:

org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint ["FKAM8LLDERP40MVBBWCEQPU6L2S: PUBLIC.BOOK_CATEGORY FOREIGN KEY(CATEGORY_ID) REFERENCES PUBLIC.CATEGORY(ID) (2)"; SQL statement:
insert into book_category (book_id, category_id) values (?, ?) [23506-196]]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement

And this is how the classes looks: Book.class

@Entity
@Table(name = "book")
public class Book {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Column(nullable = false)
    private String title;
    private String description;
    @Column(name = "release_date")
    @Temporal(TemporalType.TIMESTAMP)
    private Date releaseDate;
    @JoinColumn(name = "cover_image")
    @OneToOne(cascade = CascadeType.MERGE)
    private UploadFile coverImage;
    @OneToOne(cascade = CascadeType.MERGE)
    private UploadFile content;
    @ManyToMany
    @JoinTable(name = "book_category", joinColumns = {@JoinColumn(name = "book_id", referencedColumnName = "id")},
        inverseJoinColumns = {@JoinColumn(name = "category_id", referencedColumnName = "id")})
    private Set<Category> categories;

    // constructors, setters, getters

}

Category.class

@Entity
@Table(name = "category")
public class Category {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Column(name = "category_name")
    private String name;
    @ManyToMany(mappedBy = "categories", fetch = FetchType.LAZY)
    private List<Book> books;

    // ...
}

Upvotes: 0

Views: 1567

Answers (1)

Gergely Bacso
Gergely Bacso

Reputation: 14651

Your are missing cascade definitions there.

Your Book Category gets written before a referenced entity (book or category) gets inserted first. This is not allowed due to the constraint you specified. The solution is to define

cascade = CascadeType.ALL

On both sides of the join (both in books and in categories). This is going to ensure that JPA persists all entities in the right order.

Upvotes: 1

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