Question

I am trying to do something like this, but using @One-To-Many instead of @ElementCollection.

public class Book {
    ...
    @ElementCollection
    Set<String> tags;
    ...
}

This creates two tables, one for Book and one for the Tags with (BookID, Tag) which works fine, except for the fact that I can’t use Criteria with @ElementCollection.

So I changed it and made a wrapper class for the tags:

public class Book {
    ...
    @OneToMany(...)
    Set<BookTag> tags;
    ...
}


public class BookTag {
    ...
    String tag;
    ...
}

The problem is that using @OneToMany annotation hibernate creates 3 tables: one for the books, one for the tags, and one to join books and tags. This solutions works perfectly but I would like to have 2 tables instead of 3, since the Tag class contains only a String.

Is there any way to use @OneToMany and make hibernate create 2 tables like it does with @ElementCollection ?

Answer 1

Yes, by specifying that the OneToMany must use a join column instead of the default (which uses a join table):

@OneToMany(...)
@JoinColumn(name = "BOOK_ID")
private Set<BookTag> tags;