PDOException when executing $stockItem->save()

Question

I am using this code to add a stock item:

$stockItem = Mage::getModel('cataloginventory/stock_item');
$stockItem->setData(array(
                   'use_config_manage_stock' => 0,
                   'manage_stock'=>1, 
                   'min_sale_qty'=>1,
                   'max_sale_qty'=>2,
                   'is_in_stock' => 1,
                   'qty' => 999
               )
);
$stockItem->save();

I am getting this error:

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (usr_web29785976_1.cataloginventory_stock_item, CONSTRAINT FK_CATINV_STOCK_ITEM_PRD_ID_CAT_PRD_ENTT_ENTT_ID FOREIGN KEY (product_id) REFERENCES catalog_product_entity (entity_id) ON)' in /var/www/web29785976/html/magento/lib/Zend/Db/Statement/Pdo.php:228 Stack trace: #0 /var/www/web29785976/html/magento/lib/Zend/Db/Statement/Pdo.php(228): PDOStatement->execute(Array) #1 /var/www/web29785976/html/magento/lib/Varien/Db/Statement/Pdo/Mysql.php(110): Zend_Db_Statement_Pdo->_execute(Array) #2 /var/www/web29785976/html/magento/app/code/core/Zend/Db/Statement.php(291): Varien_Db_Statement_Pdo_Mysql->_execute(Array) #3 /var/www/web29785976/html/magento/lib/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute(Array) #4 /var/www/web29785976/html/magento/lib/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('INSERT in /var/www/web29785976/html/magento/lib/Zend/Db/Statement/Pdo.php on line 235

Answer 1

Your stock item has no product assigned, which is required.

// assuming you have a $product
$stockItem->assignProduct($product);
$stockItem->save();

Answer 2

This is caused by the fact that a stock item must be linked to a product id.

If you want to update an existing stock item you can load it using the product id first:

$stockItem = Mage::getModel('cataloginventory/stock_item')->loadByProduct($productId);

If you want to create a stock item for a new product you can assign the product id by doing:

$stockItem->assignProduct($product);