Hibernate search across two entities without an embedded index - elasticsearch

Question

I am trying to use Hibernate Search 6 and elastic search
A simple example of what I am trying to build is as follows.
I have a Book entity, which has information like title, authorName, genre, price
I have a Shop entity which has information like shopName, phone, email, location
I have a "joining table" which does a many to many mapping between nooks and shops. ( A book can be at many shops, and a shop can have many books)
I am trying to do a search by name and location, ideally to find a book at a location nearest to the input. The standard book-author example in the documentation requires a IndexedEmbedded annotation, which is not really possible in my case because I am using a joining table.
Is there an alternative approach to solve this problem

Answer 1

My entities
#Indexed
public class Book extends PanacheEntity{
public String title;
public String authorName;
#OneToMany(mappedBy = "book", fetch = FetchType.LAZY, cascade = { CascadeType.REMOVE })
public List<BookShopRelation> bookShopRelation = new ArrayList<>();
}
#Indexed
public class Shop extends PanacheEntity{
public String name;
public String city;
#OneToMany(mappedBy = "shop", fetch = FetchType.LAZY, cascade = { CascadeType.REMOVE })
private List<BookShopRelation> bookShopRelation = new ArrayList<>();
}
#Indexed
public class BookShopRelation extends PanacheEntity{
#JoinColumn(name = "shop_id")
#ManyToOne(fetch = FetchType.EAGER, optional = false)
#IndexedEmbedded
private Shop shop;
#JoinColumn(name = "offer_id")
#ManyToOne(fetch = FetchType.EAGER, optional = false)
#IndexedEmbedded
private Book book;
}
For me what was key was to understand, was that the relation table could be indexed and used as the basis for the search
List<BookShopRelation> result = Search.session(entityManager)
.search(BookShopRelation.class) .predicate(f ->
pattern == null || pattern.trim().isEmpty() ?
f.matchAll() :
f.simpleQueryString()
.fields("book.title").matching(pattern)
)
.fetchHits(size.orElse(20));