Am I doing Doctrine subclasses correctly? Why the Error?

Question

I started to build a POS system in Doctrine. I am getting an order, but I have no clue whether or not I even set up subclasses in the proper way for Doctrine.

Here is the model I came up with for line items on an order

lineItem: line_total, order_id, type
rentLineItem: returned_date_time, item_id, sold
buyLineItem: item_id

The database looks like that. Type is either a 1 (rent) or a 2 (buy)

Here is the lineItem class

class lineItem extends Doctrine_Record
{
  public function setTableDefinition()
  {
    $this->hasColumn('line_total','int');
    $this->hasColumn('order_id','int');

    $this->setSubclasses(array(
        'rentLineItem' => array('type' => 1),
        'buyLineItem' => array('type' => 2),
      )
    );
  }

  public function setUp()
  {
    $this->hasOne('order', array('local' => 'order_id', 'foreign' => 'id'));
  }
}

Here is the rentLineItem class (buyLineItem looks similar)

class rentLineItem extends lineItem
{
  public function setTableDefinition()
  {
    $this->hasColumn('returned_date_time','datetime');
    $this->hasColumn('sold','tinyint', 2); // just in case it is sold at the end of the rental
    $this->hasColumn('item_id','int');
  }

  public function setUp()
  {
    $this->hasOne('item', array('local' => 'item_id', 'foreign' => 'id'));
}
}

Here is the code I have calling the objects

$q = Doctrine_Query::create()
->select('*')
->from('order')
->where('DATE(creation_date_time) = \'' . $theDate . '\'');

$orders = $q->execute();

$totalRents = 0;
$totalSales = 0;

foreach ($orders as $order) {
  foreach ($order->line_items as $lineItem) {
    if ($lineItem->type == 1) {
      $totalRents++;
    } else if ($lineItem->type == 2) {
      $totalSales++;
    }
  }
}

Here is the error I am getting

Fatal error: Uncaught exception 'Doctrine_Record_UnknownPropertyException' with message 'Unknown record property / related component "type" on "lineItem"' in 
/Developer/Projects/VEL/lib/vendor/doctrine/Doctrine/Record/Filter/Standard.php:55 Stack trace: #0 
/Developer/Projects/VEL/lib/vendor/doctrine/Doctrine/Record.php(1296): Doctrine_Record_Filter_Standard->filterGet(Object(lLineItem), 'type') #1 
/Developer/Projects/VEL/lib/vendor/doctrine/Doctrine/Record.php(1255): Doctrine_Record->_get('type', true) #2 
/Developer/Projects/VEL/lib/vendor/doctrine/Doctrine/Access.php(72): Doctrine_Record->get('type') #3 
/Developer/Projects/VEL/manage/manage/dailyincomeexpensereport.php(29): Doctrine_Access->__get('type') #4 {main} thrown in 
/Developer/Projects/VEL/lib/vendor/doctrine/Doctrine/Record/Filter/Standard.php on line 55

Answer 1

Add a $this->hasColumn('type','int'); above your subclass call. You have to declare the column first before you use it for subclassing.

Also, in your subclass setTableDefinition calls, add a parent::setTableDefinition(); statement at the top. Also do the same with the setUp() methods. It may or may not solve your problem, but that may cause problems in the future. As for what you're referring to, when Doctrine hydrates the relationship collections, the last time I used column aggregation inheritance it did the same thing to me...It may simply not be supported unless you're querying directly.