Programmatically: How to use Magento's resource models

Step 1: Create a resource model for your entity

In your module's etc/di.xml file, add the following code to define the resource model:

	
    
    
        
            MyModule_Model_Resource_MyEntity
        
    
	
	

Create a new file MyModule/Model/Resource/MyEntity.php and add the following code:

		class MyModule_Model_Resource_MyEntity extends Mage_Core_Model_Resource_Db_Abstract
{
    protected function _construct()
    {
        $this->_init('my_module/my_entity', 'entity_id');
    }
}
	

This sets up the resource model to use the my_module/my_entity table and the entity_id column as the primary key.

Step 2: Create a collection class for your entity

Create a new file MyModule/Model/Resource/MyEntity/Collection.php and add the following code:

	class MyModule_Model_Resource_MyEntity_Collection extends Varien_Data_Collection_Db
{
    protected function _init()
    {
        parent::_init('my_module/my_entity');
    }
}
	

This sets up the collection class to use the my_module/my_entity table.

Step 3: Use the resource model programmatically

Now, you can use the resource model to retrieve all entities of type MyEntity from the database:

	$collection = Mage::getResourceModel('my_module/my_entity_collection');
	$entities = $collection->getItems();
	foreach ($entities as $entity) {
    // Do something with each entity
}
	

In this example, we're using the Mage::getResourceModel() method to get an instance of the MyModule_Model_Resource_MyEntity_Collection class. We then call the getItems() method to retrieve all entities from the database.