laravel relationships code example

Example 1: laravel where has

use Illuminate\Database\Eloquent\Builder;

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

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

Example 2: how to use where relationship laravel

Event::with(["owner", "participants" => function($q) use($someId){
    $q->where('participants.IdUser', '=', 1);
    //$q->where('some other field', $someId);
}])

Example 3: one to many laravel

For example, a blog post may have an infinite number of comments. And a single
comment belongs to only a single post  

class Post extends Model
{
    public function comments()
    {
        return $this->hasMany('App\Models\Comment');
    }
}

class Comment extends Model
{
    public function post()
    {
        return $this->belongsTo('App\Models\Post');
    }
}

Example 4: laravel detach

// Detach a single role from the user...
$user->roles()->detach($roleId);

// Detach all roles from the user...
$user->roles()->detach();

Example 5: 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 6: laravel eloquent associate

$account = App\Account::find(10);

$user->account()->associate($account);

$user->save();