Laravel Eloquent: Get record that contains two specific relations - php

Question

I have a project where a user can create conversations with other users. A conversation can belongsToMany users and user can belongsToMany conversations.
I now need to get the conversation in which two specific users participate.
I tried a combination of solutions using whereIn and I tried the following:
$c = Conversation::whereHas('users', function($q)
{
$q->whereIn('user_id', array(1,3));
})
->get();
Here the problem is that whereIn('user_id', [1,3]) gets records that contains EITHER 1 or 3. I need it to return records that contains BOTH 1 and 3.
Conversation Model
class Conversation extends Model {
public function users(){
return $this->belongsToMany('App\User');
}
}
User Model
class User extends Model {
public function conversations(){
return $this->belongsToMany('App\Conversation');
}
}
Tables
conversations:
id | subject
conversation_user:
id | user_id | conversation_id
Data from table conversation_user

Answer 1

Your newest edit makes a lot more sense, this is actually a very easy fix. whereHas takes two additional parameters where it's going to look for the count.
$users = [1, 3];
$c = Conversation::whereHas('users', function($q) use ($users)
{
$q->whereIn('user_id', $users);
}, '>', count($users) )
->get();
This will get all conversations where user's 1 and 3 have participated in, even if there are additional users that have participated in those conversations. If you want only the conversations with only users 1 and 3, change the > to an =.
Edit: I just realized your pivot table has an id column. This method may not work if your pivot table is going to have duplicates. For example, if you have user_id of 1 in there twice with the same conversation_id both times, it will return that conversation even though it technically only has 1 user. I suggest removing the id column and creating a composite primary key of user_id and conversation_id. If there is the possibility of duplicates, it might be safer to use lukasgeiter's solution.

Answer 2

You are currently querying conversations which either user 1 and/or 3 takes part in. To achieve what you want you need two whereHas calls:
$c = Conversation::whereHas('users', function($q)
{
$q->where('user_id', 1);
})
->whereHas('users', function($q)
{
$q->where('user_id', 3);
}
->get();
And if you have more than two users, add them in a loop:
$users = [1, 2, 3, 4, 5];
$c = Conversation::query();
foreach($users as $userId){
$c->whereHas('users', function($q) use ($userId)
{
$q->where('user_id', $userId);
});
}
$c = $c->get();

Answer 3

I hope this will help you...
$userIds = array(1,3);
$c = Conversation::whereHas('users', function($q) use ($userIds)
{
$q->whereIn('user_id', $userIds);
})
->get();