Where NOT in pivot table - laravel

Question

In Laravel we can setup relationships like so:
class User {
public function items()
{
return $this->belongsToMany('Item');
}
}
Allowing us to to get all items in a pivot table for a user:
Auth::user()->items();
However what if I want to get the opposite of that. And get all items the user DOES NOT have yet. So NOT in the pivot table.
Is there a simple way to do this?

Answer 1

Looking at the source code of the class Illuminate\Database\Eloquent\Builder, we have two methods in Laravel that does this: whereDoesntHave (opposite of whereHas) and doesntHave (opposite of has)
// SELECT * FROM users WHERE ((SELECT count(*) FROM roles WHERE user.role_id = roles.id AND id = 1) < 1) AND ...
User::whereDoesntHave('Role', function ($query) use($id) {
$query->whereId($id);
})
->get();
this works correctly for me!
For simple "Where not exists relationship", use this:
User::doesntHave('Role')->get();
Sorry, do not understand English. I used the google translator.

Answer 2

For simplicity and symmetry you could create a new method in the User model:
// User model
public function availableItems()
{
$ids = \DB::table('item_user')->where('user_id', '=', $this->id)->lists('user_id');
return \Item::whereNotIn('id', $ids)->get();
}
To use call:
Auth::user()->availableItems();

Answer 3

It's not that simple but usually the most efficient way is to use a subquery.
$items = Item::whereNotIn('id', function ($query) use ($user_id)
{
$query->select('item_id')
->table('item_user')
->where('user_id', '=', $user_id);
})
->get();
If this was something I did often I would add it as a scope method to the Item model.
class Item extends Eloquent {
public function scopeWhereNotRelatedToUser($query, $user_id)
{
$query->whereNotIn('id', function ($query) use ($user_id)
{
$query->select('item_id')
->table('item_user')
->where('user_id', '=', $user_id);
});
}
}
Then use that later like this.
$items = Item::whereNotRelatedToUser($user_id)->get();

Answer 4

How about left join?
Assuming the tables are users, items and item_user find all items not associated with the user 123:
DB::table('items')->leftJoin(
'item_user', function ($join) {
$join->on('items.id', '=', 'item_user.item_id')
->where('item_user.user_id', '=', 123);
})
->whereNull('item_user.item_id')
->get();

Answer 5

this should work for you
$someuser = Auth::user();
$someusers_items = $someuser->related()->lists('item_id');
$all_items = Item::all()->lists('id');
$someuser_doesnt_have_items = array_diff($all_items, $someusers_items);

Answer 6

Ended up writing a scope for this like so:
public function scopeAvail($query)
{
return $query->join('item_user', 'items.id', '<>', 'item_user.item_id')->where('item_user.user_id', Auth::user()->id);
}
And then call:
Items::avail()->get();
Works for now, but a bit messy. Would like to see something with a keyword like not:
Auth::user()->itemsNot();
Basically Eloquent is running the above query anyway, except with a = instead of a <>.

Answer 7

Maybe you can use:
DB::table('users')
->whereExists(function($query)
{
$query->select(DB::raw(1))
->from('orders')
->whereRaw('orders.user_id = users.id');
})
->get();
Source: http://laravel.com/docs/4.2/queries#advanced-wheres

Answer 8

This code brings the items that have no relationship with the user.
$items = $this->item->whereDoesntHave('users')->get();