How to print collection mysql query in magento - debugging

Question

Let's say I have a collection like:
$products = Mage::getModel('catalog/product')
->getCollection()
...
->load();
How do I print the actual MySQL code that gets executed?

Answer 1

You can always view your sql query at a certain point by echoing getSelect as shown:
$products = Mage::getModel('catalog/product')
->getCollection();
echo $products->getSelect();
To change query parameters you want to check out methods like:
$products->addAttributeToSelect('someattribute');
$products->addAttributeToFilter('someattribute', array('eq'=>'1'));

Answer 2

You can print collection using below code:
We can print query of collection using getSelect()->__toString()
$products = Mage::getModel(‘catalog/product’)
->addAttributeToFilter(‘status’, array(‘eq’ => 1));
echo $products->getSelect()->__toString();
Have you seen http://kuldipchudasama.wordpress.com/2012/07/16/magento-print-query-of-collection/?
This works well.

Answer 3

Most other answers here say that $products->getSelect() will do it - this is fine if all you're going to do with it is echo, but in fact getSelect() doesn't just return a string, it returns a Varien_Db_Select object.
Invoking echo on that object automatically triggers its __toString() method, so you just get the SQL string, but try passing it to Mage::log() and you'll get a lot more than you expected.
If you just want to log the SQL, you can use:
Mage::log($products->getSelect()->__toString());
Or how about using the object's own:
$products->printLogQuery(false, true); // don't echo, do log
printLogQuery is defined in lib/Varien/Data/Collection/Db.php.

Answer 4

You can print
$products->getSelect()->assemble();

Answer 5

I work with collections every day. This is without a doubt the correct way.
echo $collection->getSelectSql(true);

Answer 6

If you simple set the first parameter of ->load() to true, like so:
$products = Mage::getModel('catalog/product')
->getCollection()
...
->load(true);

Answer 7

In Magento 2:-
namespace <Company>\<Module>\Block\Adminhtml\Tab\Log;
class Grid
extends \Magento\Backend\Block\Widget\Grid\Extended
{
protected $_collectionFactory;
/**
* Constructor
*
* #param \Magento\Backend\Block\Template\Context $context
* #param \Magento\Backend\Helper\Data $backendHelper
* #param \<Company>\<Module>\Model\ResourceModel\Log\CollectionFactory $collectionFactory
* #param Psr\Log\LoggerInterface $logger
* #param array $data
*/
public function __construct(
\Magento\Backend\Block\Template\Context $context,
\<Company>\<Module>\Model\ResourceModel\Log\CollectionFactory $collectionFactory,
\Psr\Log\LoggerInterface $logger,
array $data = []
) {
$this->_logger = $logger;
$this->_collectionFactory = $collectionFactory;
parent::__construct($context, $backendHelper, $data);
}
/**
* {#inheritdoc}
*/
protected function _prepareCollection()
{
$collection = $this->_collectionFactory->create();
$this->_logger->info($collection->getSelect()->__toString());
$this->setCollection($collection);
return parent::_prepareCollection();
}
}
And remember that the collection factory is a magic class that can attaches to every class as Magento 1 wasn't complicated enough.

Answer 8

Step 1-
$result_colletion = print_r($collection->getSelect());
Mage::log($$result_colletion, null, custom_collection.log,true);
Step 2-
After that Login into magento admin section and enable to log setting . Please see below .
System > Configuration > Developer > Log Settings
Step 3-
After that see the log file custom_collection.log in var/log/ folder .

Answer 9

Try following code.
$products = Mage::getModel('catalog/product')
->getCollection();
echo $products->getSelect();