CODEWITHSUNDEEP
symfonydoctrine-orm
johnnietheblack
johnnietheblack

Reputation: 13340

Do Many-To-Many relationships required a "join entity" in Symfony 2 / Doctrine?

I am starting to understand how Symfony 2 and Doctrine handle many to many relationships, but I am stuck on something, that I seem to have read differing opinions on.

Let's say I have an Author entity and a Book entity...with a many-to-many relationship between them.

In my database, I represent this with three tables, an authors table, a books table, and an authors_books table (which basically just joins them together.

In Symfony 2, do I also create an AuthorsBooks entity, which would have the sole purpose of joining the Author and Book entities together? Or, does Symfony handle that for me?

Upvotes: 0

Views: 1401

Answers (2)

Reuven
Reuven

Reputation: 3336

If there is nothing else than the association of authors and books, you don't need to create the AuthorsBooks entity.

You have two options now, Unidirectional or Bidirectional. You'll be able to find more information directly in Doctrine2 documentation here

For unidirectional, you'll have something like that (yml):

Author:
  type: entity
  manyToMany:
    bookList:
      targetEntity: Group
      joinTable:
        name: authors_books
          joinColumns:
            user_id:
              referencedColumnName: id
          inverseJoinColumns:
            book_id:
              referencedColumnName: id

Upvotes: 2

Crozin
Crozin

Reputation: 44406

Symfony has nothing to do with this, it's strictly Doctrine's thing. But, no, you do not have to create a AuthorsBooks entity. All you have to do is to configure Doctrine properly, i.e. use @JoinTable annotation that specifies which table should be used to join two entities.

Upvotes: 1

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