How can I update related models in yii 2 - yii2

Question

I have 3 tables to manage my stock.
Items_table (item_id,label,stock...) column stock has 0 default value.
orders_table (order_id,at_date,status) column status has 0 default value.
orders_items_table(orderitem_id,order_id,item_id,quantity) manage orders details.
what I want to do is to update order 'status' 1 and update Items 'stock' with quantity from orders_items_table by concerned item_id.
here is my actionValidate
public function actionValidate($id)
{
$model = $this->findModel($id);
$query = new purchases::find()->where('purchase_id' = :id);
echo $query->createCommand()->sql;
if ($model->load(Yii::$app->request->post()) && $model->save()) {
return $this->redirect(['view', 'id' => $model->purchase_id]);
}
return $this->render('validate', [
'model' => $model,
]);
}

Answer 1

So you should end up with three models.
Step 1: create three ActiveRecord model I will create one for you only
class Order extends \yii\db\ActiveRecord
{
public static function tableName()
{
return 'orders';
}
public function rules()
{
return [
[['id','status'], 'integer'],
];
}
public function attributeLabels()
{
return [
'id' => Yii::t('app', 'Order Id'),
'status' => Yii::t('app', 'Order Status'),
'created_at' => Yii::t('app', 'Order Date'),
];
}
public function getOrderItems()
{
return $this->hasMany(OrderItem::className(), ['order_id' => 'id']);
}
public function getItems()
{
return $this->hasMany(Item::className(), ['id' => 'item_id'])
->via('orderItems');
}
}
Now you need to create OrderItem model, OrderItem hasOne Order and hasOne Item. After that create Item model that have many OrderItem and Orders.
Step 2: create your controller and the following
$order = Order::findOne($order_id);
if( ! is_null($order) ){
//we found the order
foreach ($order->orderItems as $orderItem) {
//get the item
$item = $orderItem->item;
$item->stock = $item->stock - $orderItem->quantity;
//save the item
$item->save();
}
//update the order
$order->status = 1;
$order->save();
}
That code just to show you how to do the logic don't forget you need to do validation and data integrity.
see more Active Record