BD

Query from anywhere

$resource = Mage::getSingleton('core/resource');
  $readConnection = $resource->getConnection('core_read');

  $query = 'SELECT * FROM multicarriershipping_tablerate_groups';
  $results = $readConnection->fetchAll($query);

Verify if collection is empty

$safeToDelete = $model->getCollection()
                ->addFieldToFilter('doctor_id',$customerData->getId())
                ->addFieldtoFilter('relation_id', $relatedId);

  if ($safeToDelete->getSize()) {
  
  }

Debug query sql

  var_dump($collection->getSelect()->__toString());

Return customer by full name using like

$customers = Mage::getModel('customer/customer')->getCollection()
->addExpressionAttributeToSelect('full_name','LOWER(CONCAT({{firstname}},"  ",{{lastname}}))', array('firstname','lastname'));

// usando filtro com like
$collection->addAttributeToFilter(‘full_name’,array(‘like’=>’%’.$filtro.’%'))