Query relation in same table with Eloquent ORM in Laravel 4.1 - php

Question

I am just discovering Laravel, and getting into Eloquent ORM. But I am stumbling on a little issue that is the following.
I have three tables with the following structures and data :
words
id | language_id | parent_id | word
-------------------------------------------
1 | 1 | 0 | Welcome
-------------------------------------------
2 | 2 | 1 | Bienvenue
-------------------------------------------
documents
id | title
---------------------
1 | Hello World
---------------------
documents_words
document_id | word_id
--------------------------
1 | 1
--------------------------
As you see, we have a parent/child relationship in the words table.
The documents Model is defined as following
class Documents extends Eloquent {
protected $table = 'documents';
public function words()
{
return $this->belongsToMany('Word', 'documents_words', 'document_id');
}
}
And the words model :
class Word extends Eloquent {
protected $table = 'words';
public function translation()
{
return $this->hasOne('Word', 'parent_id');
}
}
Now my problem is that I want to retrieve documents that have translated words, so I thought this would do it :
$documents = Documents::whereHas('words', function($q)
{
$q->has('translation');
})
->get();
But I get 0 results, so I checked the query that Eloquent generates and uses :
select * from `prefix_documents`
where
(
select count(*) from
`prefix_words`
inner join `prefix_documents_words`
on `prefix_words`.`id` = `prefix_documents_words`.`word_id`
where `prefix_documents_words`.`document_id` = `prefix_documents`.`id`
and (select count(*)
from `prefix_words`
where `prefix_words`.`parent_id` = `prefix_words`.`id`) >= 1
) >= 1
The problem is that it doesn't use aliases for the tables, what my query should be more like this to work (and it does) :
select * from `prefix_documents`
where
(
select count(*) from
`prefix_words`
inner join `prefix_documents_words`
on `prefix_words`.`id` = `prefix_documents_words`.`word_id`
where `prefix_documents_words`.`document_id` = `prefix_documents`.`id`
and (select count(*)
from `prefix_words` as `w`
where `w`.`parent_id` = `prefix_words`.`id`) >= 1
) >= 1
But how can I do this with Eloquent ORM ?
Thanks a lot for your help guys, hope I am clear enough.

Answer 1

In the Word Model, change the
public function translation()
{
return $this->hasOne('Word', 'parent_id');
}
to
public function translation()
{
return $this->belongsToMany('Word', 'words', 'id', 'parent_id');
}
This way we are telling the Laravel to create an alias in the eloquent when using your query. I didn't test the other cases, but I think it will work.