Laravel 4 - Finding out if an M:N relation exists between 2 models

Question

I have 2 models, one is a Poll, and another is an User. I have set up a M:N relationship between both of them:

User.php

public function votedPolls() {
    return $this->belongsToMany('Polls', 'votes');
}

Poll.php

public function voters() {
    return $this->belongsToMany('User', 'votes');
}

And it all works nicely. When I vote on a poll, the table votes get populated properly. But now I want to check inside the controller if a user has already voted in a poll.

I figured it would be something like this, but I am not sure of the syntax. I tried this (which does not work):

$voters = $poll->voters()->where('id', '=', $user->id)->first();
$voted = count($voters) == 1;

How could I achieve this?

Duplicate, check this http://stackoverflow.com/questions/23910553/laravel-check-if-related-model-exists#answer-23911985 — Jarek Tkaczyk, Jul 11 '14 at 08:23
That tells me if a relationship exists, but wont tell me if the objects of the model have a relationship stablished? — Enrique Moreno Tent, Jul 11 '14 at 09:33
Why the code you tried does not work exactly? I assume you need to use `where('users.id','=',$user->id)` because pivot table also has `id` column, just a guess. — Jarek Tkaczyk, Jul 11 '14 at 09:45
That was it! Put it on an answer, and Ill give you the credit :) — Enrique Moreno Tent, Jul 11 '14 at 10:04

score 1 · Accepted Answer · answered Jul 11 '14 at 10:19

1

count is preferred way of checking if relations exist.

Your code didn't work because your pivot table also has id column and where clause was ambiguous, so change it to:

where('users.id','=',$user->id)

answered Jul 11 '14 at 10:19

Jarek Tkaczyk

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Laravel 4 - Finding out if an M:N relation exists between 2 models

1 Answers1