Solved: Integrity Constraint Violation Error Referring to quote_item Table While Adding Product to Cart in Magento 2

Magento 2 CMS allows customizing the default features based on business requirements. Magento 2 events are implemented to run custom code in response to any particular Magento 2 event or custom event.

In this post, I am posting the solution for the error that occurs while using the event “checkout_cart_product_add_after”.

You can use this event when you want to automatically add a product to the cart when the customer adds another specific product to the cart.

For example, a processing fee or a free item can be automatically added as a product when a customer chooses to purchase an item.

However, when you implement the same using the “checkout_cart_product_add_after” event, you may face an error that states,

Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fail

The error occurs because the automated item is saved.

All you need to do is remove or comment the $item->save();

Once you remove “$item->save();”, you’ll get the solution of the integrity constraint violation error referring to quote_item table while adding product to cart in Magento 2.

That’s it.

Please mention any doubts about the event or the error in the Comments section below. I’d be happy to help.

Also, I’d be grateful if you could share the solution with the Magento Community via social media.

Thank you.