YII Insert or Update a Row

// try to find a row
$model = someModel::find()
    ...
    ->one();

// if exist a row, return the model
// otherwise return null
// now check if the model is null

if (is_null($model)) {
    $model = new someModel();
}

// apply your change
$model->attributes = $attributes;
...

// insert or update
$model->save();