laravel related as join code example

Example 1: laravel join

Inner Join 	: ->join('contacts', 'users.id', '=', 'contacts.user_id')
Left Join 	: ->leftJoin('posts', 'users.id', '=', 'posts.user_id')
Right Join 	: ->rightJoin('posts', 'users.id', '=', 'posts.user_id')
Cross Join 	: ->crossJoin('colors')

Advance Queries : 
----------------- 
 		->join('contacts', function ($join) {
            $join->on('users.id', '=', 'contacts.user_id')
                 ->where('contacts.user_id', '>', 5);
        })

Example 2: laravel join

$users = DB::table('users')
            ->join('contacts', 'users.id', '=', 'contacts.user_id')
            ->join('orders', 'users.id', '=', 'orders.user_id')
            ->select('users.*', 'contacts.phone', 'orders.price')
            ->get();

Example 3: whereHas site:https://laravel.com/docs/

use Illuminate\Database\Eloquent\Builder;

// Retrieve posts with at least one comment containing words like code%...
$posts = Post::whereHas('comments', function (Builder $query) {
    $query->where('content', 'like', 'code%');
})->get();

// Retrieve posts with at least ten comments containing words like code%...
$posts = Post::whereHas('comments', function (Builder $query) {
    $query->where('content', 'like', 'code%');
}, '>=', 10)->get();

Example 4: latavel attach method

$user->roles()->attach($roleId, ['expires' => $expires]);