Foreign Key In MySQL using Yii

I have the database just like this

==== Invoices ====
id
customer_id
description

==== Customers ===
id
firstname
lastname

Now I have made the relation in between models just like this. In Invoices models the relation is as like this

public function relations()
{
    return array(
        'customer' => array(self::BELONGS_TO, 'Customer', 'customer_id')
    );
}

In customer model the relation is just like this

public function relations()
{
    return array(
      'invoice' => array(self::HAS_MANY, 'Invoices','customer_id')
    );
}

Now as my relation is defined one customer has many invoices and the invoice is belongs to the customer.

Now I made multimodel and loaded the Customer model into Invoice model just like this.

public function actionCreate()
{
    $model = new Invoices;
    $customers = new Customers;
    // Uncomment the following line if AJAX validation is needed
    // $this->performAjaxValidation($model);

    if (isset($_POST['Invoices'],$_POST['Customers']))
    {
      $model->attributes = $_POST['Invoices'];
      $customers->attributes = $_POST['Customers'];
      $valid = $model->validate();
      $valid = $customers->validate();
      if($valid)
      {
        $model->save(false);
        $customers->id = $model->customer_id;
        $customers->save(false);
        $this->redirect(array('view','id'=>$model->id));
      }
    }

    $this->render('create',array(
      'model'=>$model,
      'customers'=>$customers,
    ));
}

Here everything is okay. I can insert the data for both models easily. But my problem comes here in the way that when I am inserting data from Invoice multimodel the foreign key id is not changing. It is showing zero every time. Can some one tell me where I am wrong.

Any help and suggestions will be highly appreciated.

Solution

My guess is that you are overriding the customer's primary key with the invoice's foreign key. I do not say that's not correct that way (maybe in your scenario it makes sense).

Let me explain what you are doing in that code:

First, you create new instances of two models, Invoices and Customers. Yii understands that as "they wish to insert new items in the database".
Then, you check if there are the items coming from an ajax form. If true, then,
You populate Invoices (defined as $model. I'd change it to $invoice, in case you need to edit and understand it further).
You also popupulate the customer's information, overriding the $valid value (so, you don't know if invoice is actually valid).
If valid (remember you're only validating customer's information), do,
Save the invoice
Override customer's id with invoice's foreing key to customer.
Save the customer, and redirect.

Now, what I got from that:

$valid doesn't work as expected: I'd change that to an incremental assignment.
You may not be passing a customer_id coming from the ajax form. Foreing keys are integers, and so if not defined within a model, it becomes 0 or NULL.
You are always passing id = 0 / NULL to Customer's model, so it would probably warn you when validating. However, you are using save(false), which means it doesn't pre-validate on save, so you never know it doesn't work.

So, according to this:

  public function actionCreate()
  {
    $invoice = new Invoices;
    $customers = new Customers;
    // Uncomment the following line if AJAX validation is needed
    // $this->performAjaxValidation($invoice);

    if (isset($_POST['Invoices'],$_POST['Customers']))
    {
      $invoice->attributes = $_POST['Invoices'];
      $customers->attributes = $_POST['Customers'];
      $valid = true; /* expect it is always valid */
      $valid &= $invoice->validate(); /* if $invoice is not valid, $valid will be false (true&false = false) */
      $valid &= $customers->validate(); /* same as the above line */
      if($valid)
      {
        $customers->save(); /* First save customers. It's the Foreign item */
        $invoice->customer_id = $customers->getPrimaryKey(); /* new instances use getPrimaryKey() to get its id */
        $invoice->save(); /* Save invoice AFTER getting customer's primary key */
        $this->redirect(array('view','id'=>$invoice->id));
      }
    }

    $this->render('create',array(
      'invoice'=>$invoice,
      'customers'=>$customers,
    ));
  }

I hope this solves your problem.