autocde2.0/app/Observers/AssetObserver.php

<?php

namespace App\Observers;

use App\Models\Asset;

class AssetObserver
{
    /**
     * Handle the Asset "created" event.
     */
    public function created(Asset $asset): void
    {
        //
    }

    /**
     * Handle the Asset "updated" event.
     */
    public function updated(Asset $asset): void
    {
        //
    }

    /**
     * Handle the Asset "deleted" event.
     */
    public function deleted(Asset $asset): void
    {

    }

    public function deleting(Asset $asset): void
    {
        // 解除 asset 与 requirementGroups 的关联，但不删除 requirementGroups
        $asset->requirementGroups()->update(['asset_id' => null]);


        // 遍历 requirements，解除每个 $requirement 与 projects 的关联
        foreach ($asset->requirements as $requirement) {
            $requirement->projects()->detach();
        }

        // 类似地，解除 asset 与 requirements 的关联
        $asset->requirements()->update(['asset_id' => null]);

        // 遍历 plans，解除每个 plan 与 projects 的关联
        foreach ($asset->plans as $plan) {
            $plan->projects()->detach();
        }

        $asset->plans()->delete();

    }

    /**
     * Handle the Asset "restored" event.
     */
    public function restored(Asset $asset): void
    {
        //
    }

    /**
     * Handle the Asset "force deleted" event.
     */
    public function forceDeleted(Asset $asset): void
    {
        //
    }
}