Question

I’ve encountered a problem while trying to fetch some information that I thought should be there between related entities in Symfony2 with Doctrine.

Let’s say I have an entity called “Publisher” which haves many “Magazines” which have many “Chapters” which have many “Pages”, and I want to fetch, from one “Publisher” object get the total amount of Pages that all their Magazines, through chapters, have.

Whil trying to count the Magazines, directly related, I have no problem (I’m using Twig as template).
In the controller i retrieve the list:

$entities = $em->getRepository('Bundle:Publisher')->findAll();

And in the view I can render this:

{{ entity.magazines.count }}

Which gives me the Magazines related to that publisher. But when i try to do the following:

{{ entity.magazines.chapters.count }}

(Assuming “Chapters” is another entity related ManyToOne Magazine) it throws an error.
I know I’m missing something here but I cannot figure out what it is. Could someone help me or give a tip on how to do this?

Answer 1

You can’t do that in this way. You should use the DQL instead.

At now after accessing entity.magazines you get a Collection of Magazine Entities and you should loop this collection to access the chapters of the each items in the entity.magazines collection

So see the Using Aggregate Functions here