fix cascade delete

app/Http/Controllers/TokensController.php

@@ -191,7 +191,9 @@ class TokensController extends Controller
 
     public function destroy(Tokens $token)
     {
-        $token->campaigns()->delete();
+        $token->cities()->update([
+            'token_id' => null,
+        ]);
         $token->delete();
 
         return Redirect::route('tokens')->with('success', 'Token deleted.');

database/migrations/2021_05_11_084828_create_campaigns_table.php

@@ -37,7 +37,8 @@ class CreateCampaignsTable extends Migration
             $table->timestamp('disabled_at')->nullable();
             $table->timestamps();
 
-            $table->foreign('token')->references('id')->on('tokens');
+            $table->foreign('token')->references('id')->on('tokens')
+                ->cascadeOnDelete();
         });
     }