在 Laravel 6 中一次保存两个相互关联的新模型

Question

I'm wondering what's the best way to save two different models with a relationship to each other at once. Consider I have a Subscription model and a Participant model, and when I create a Participant, it has to create a Subscription and link the Participant to it.

Example:

class Subscription extends Model
{
    public function participants()
    {
        return $this->hasMany('App\Participant');
    }
}

---

class Participant extends Model
{
    public function subscription()
    {
        return $this->belongsTo('App\Subscription');
    }
}

---

Saving:

$s = new App\Subscription();

$p = new App\Participant();

$s->participants()->save($p);

But then the Subscription isn't saved. Any ideas what's the best practice to save them both, check if they're saved and make the relation?

Answer 1

What you're looking for is transactions. You can do them 2 ways.

Using DB::transaction() and putting everything in a Closure

use DB;

$s = new App\Subscription();
$p = new App\Participant();

DB::transaction(function () use ($s, $p) {
    // If something fails, it will rollBack, if not, it will commit.
    $s->save();
    $s->participants()->save($p);
});

Or manually, where you control when it's commited or rollback'd.

use DB;

$s = new App\Subscription();
$p = new App\Participant();

try {
    DB::beginTransaction();
    $s->save();
    $s->participants()->save($p);
    DB::commit();
} catch (\Exception $e) {
    DB::rollBack();
}

More info on transactions

Answer 2

You can do that with transactions (as in @IGP's answer), or just add saving line for subscriptions too..

public function test()
{
    // Begin Transaction
    DB::beginTransaction();

    try
    {
        $participant = new Participant();

        $subscription = new Subscription();
        // $subscription->name = "parent subscription"; // init necessary columns
        $subscription->save();

        $participant->subscription()->associate($subscription);
        // $participant->name = "child participant"; // init necessary columns
        $participant->save();

        // Commit Transaction
        DB::commit();

        // Continue your logic here

    } catch (\Exception $e) {
        // Rollback Transaction
        DB::rollback();

        return $e->getMessage();
    }
}