using 'And Where' in Many to Many relation - php

Question

I have two models which have a many-to-many relationship.
class User extends Model
{
function cars()
{
return $this->belongsToMany(Car::class);
}
}
class Car extends Model
{
function users()
{
return $this->belongsToMany(User::class);
}
}
I want to get users who used a specific set of cars:
$car_selected = [1, 3, 6];
$users = User::when(count($car_selected) > 0, function ($q) use ($car_selected) {
$q->whereIn('cars.id', $car_selected);
})
->get();
This gives too many results because of the 'whereIn' condition; what I want is 'whereAnd' something.
I tried this, but no luck.
$users = User::when(count($car_selected) > 0, function ($q) use ($car_selected) {
foreach($car_selected as $xx) {
$q->where( 'cars.id', $xx);
}
})
->get();
How can I get all users which have a relationship to cars 1, 3, and 6?

Answer 1

Your code provided doesn't make a lot of sense, but based on your explanation, you want to find a user who has a relationship with cars 1 and 3 and 6. Using whereIn() gets you users with relationships with cars 1 or 3 or 6.
Your attempt with multiple where() filters wouldn't work, as this would be looking for a single row in the pivot table with multiple cars, which obviously wouldn't be possible. Instead, you need to nest multiple whereHas() relationship filters into a single where() group like this:
$users = User::where(function ($q) use ($car_selected) {
foreach ($car_selected as $car) {
$q->whereHas('cars', function ($query) use ($car) {
$query->where('car_id', $car);
});
}
})
->with(['cars' => function ($q) use ($car_selected) {
$q->whereIn('car_id', $car_selected);
}])
->get();
This is all assuming you've correctly set up your relationships and tables per Laravel standards.
Demo code is here: https://implode.io/anjLGG

Answer 2

You can use the whereHas method to query relationship:
use Illuminate\Database\Eloquent\Builder;
User::whereHas('cars', function (Builder $builder) use($car_selected)
{
$builder->whereIn( 'cars.id', $car_selected);
})->get();
For more infos, check the doc

Answer 3

as #miken32 explained, I need to nest multiple whereHas() relationship filters into a single where() group.
#miken32 proposed following..
$users = User::where(function ($q) use ($car_selected) {
foreach ($car_selected as $car) {
$q->whereHas('cars', function ($query) use ($car) {
$query->where('car_id', $car);
});
}
})
->with(['cars' => function ($q) use ($car_selected) {
$q->whereIn('car_id', $car_selected);
}])
->get();
And I guess following is enough .
$users = User::where(function ($q) use ($car_selected) {
foreach ($car_selected as $car) {
$q->whereHas('cars', function ($query) use ($car) {
$query->where('car_id', $car);
});
}
})->get();
Thanks.