3 comma to ; change
source | link

For NULL values, not empty ones you can also set condition like

 $collection = Mage::getModel('catalog/product')
        ->getCollection()
        ->addFieldToFilter('weight', array('null'=>true),
 ;

For NULL values, not empty ones you can also set condition like

 $collection = Mage::getModel('catalog/product')
        ->getCollection()
        ->addFieldToFilter('weight', array('null'=>true),

For NULL values, not empty ones you can also set condition like

 $collection = Mage::getModel('catalog/product')
        ->getCollection()
        ->addFieldToFilter('weight', array('null'=>true)
 ;
2 added 16 characters in body
source | link

For NULL values, not empty ones you can also set condition like $collection = Mage::getModel('catalog/product') ->getCollection() ->addFieldToFilter('weight', array('null'=>true),

 $collection = Mage::getModel('catalog/product')
        ->getCollection()
        ->addFieldToFilter('weight', array('null'=>true),

For NULL values, not empty ones you can also set condition like $collection = Mage::getModel('catalog/product') ->getCollection() ->addFieldToFilter('weight', array('null'=>true),

For NULL values, not empty ones you can also set condition like

 $collection = Mage::getModel('catalog/product')
        ->getCollection()
        ->addFieldToFilter('weight', array('null'=>true),
1
source | link

For NULL values, not empty ones you can also set condition like $collection = Mage::getModel('catalog/product') ->getCollection() ->addFieldToFilter('weight', array('null'=>true),