public function qualityAssuranceModules($courseId, $currenModuleIdsArr) { $modules = Module::where('course_id', '=', $courseId)->select('module_id')->get(); $fromDBArr = array(); foreach ($modules as $mod) { $fromDBArr[] = $mod['module_id']; } $toBeDeleted = array_diff($fromDBArr, $currenModuleIdsArr); foreach ($toBeDeleted as $module) { //TODO: verify cascading delete Module::where('course_id', '=', $courseId)->where('module_id', '=', intval($module))->delete(); } }