How to use a Magento 1 model to update multiple rows?

Question

I am processing some records and I need to set a datetime field to the current time for multiple rows. I have all the row IDs. What's the best way to do this with Magento 1? The SQL would be like this:

update
    my_table
set
    processed_on = "2015-09-09 11:11:04"
where
    id in(34, 56, 77, 39)

Answer 1

Instead of load/save inside foreach, you can try this:

$collection = Mage::getModel('your/model')->getCollection()
    ->addIdFilter(array(1,2,3));

foreach ($collection as $item) {
    $item->setProcessedOn('2015-09-09 11:11:04');
}
$collection->save();

Answer 2

To update existing rows in a model, you need to load each row first, call addData() with the new data, then save the row.

An example would look like this:

$rowIds = array(1,2,3)
foreach($rowIds as $rowId) {
    $data = array('processed_on' => "2015-09-09 11:11:04");

    $model = Mage::getModel('your_model')->load($rowId)->addData($data);   
    try {
        $model->setId($rowId)->save();  
        echo "Record updated";  
    } catch (Exception $e){  
        echo $e->getMessage();  
    } 
}

Answer 3

I know this answer is a bit late, but I ran into this requirement today and found another answer that let me avoid doing loops with loads or saves. For your code it could look something like this:

/** @var Mage_Core_Model_Resource $resource */
$resource = Mage::getSingleton('core/resource');
/** @var Magento_Db_Adapter_Pdo_Mysql $connection */
$connection = $resource->getConnection(Mage_Core_Model_Resource::DEFAULT_WRITE_RESOURCE);
$ids = array(34, 56, 77, 39);
$connection->update('my_table', ['processed_on' => "2015-09-09 11:11:04"], ['id IN(?)' => $ids]);