Reverse contains() in laravel?

Question

I'm new to laravel, I'm trying to get a row from a table according to it's Many-to-Many relationship with another table.

You know when you pass multiple ids in contain() to check if they have relationship with that row or not, like this:

$row->contains([4,6,9]);

i want to reverse this, where i can use the ids [4,6,9] to get any row from the other table linked with them.

Answer 1

Let's say you have this two models: User and Role that makes many-to-many relationship.

If you defined your relationships properly:

/** User.php */

public function roles()
{
    return $this->belongsToMany(Role::class);
}

-

/** Role.php */

public function users()
{
    return $this->belongsToMany(User::class);
}

Then you could use the relationship to accomplish what you are trying to do.

From the related object:

$user = User::find(1);

// getting all the roles attached with a user:
$roles = $user->roles;

// getting all the roles attached with a user that has certain ids:
$roles = $user->roles()->whereIn('id', [2, 4, 6])->get();

Also, you could find your desired related model using the collection instance that return the relationship:

$user = User::find(1);

// getting all the roles attached with a user:
$roles = $user->roles;

// getting a specific role attached to a user:
$specific_role = $roles->where('id', 6)->first();