Question

I’m a newbie with Magento getResourceModel, and I’m trying to add a simple filter to my query, but i can’t figure that using getResourceModel.

Original Query:

$collection = Mage::getResourceModel('catalog/product_collection');
Mage::getModel('catalog/layer')->prepareProductCollection($collection);
$collection->addAttributeToFilter('promotion', 1)->setOrder('price', 'desc');

I just want add the where clause:

 (`price` - `final_price`) >= (`price` * 0.4) 

Someone can help me to do this?

This is all, thanks!

Answer 1

So finally I found the correct way to do this, sorry to delay to post the answer here and thanks @feeela.

Looking the file /lib/Zend/Db/Select.php I found that exists the where function:

public function where($cond, $value = null, $type = null)
{
  $this->_parts[self::WHERE][] = $this->_where($cond, $value, $type, true);

  return $this;
}

So, what we need is just add a call to this function giving the condition that we want. In my case, I just add a condition to filter products that have 40% of discount.

$collection = Mage::getResourceModel('catalog/product_collection');
Mage::getModel('catalog/layer')->prepareProductCollection($collection);
$collection->addAttributeToFilter('promotion', 1)
           ->addStoreFilter();
$collection->getSelect()->where( '(`price` - `final_price`) >= (`price` * 0.4)' ); 

So, I hope that this can be helpful for some dudes!

Grazie tutti!