Checking if object exists in database

Hi everyone,

I'm working on an application for catering companies. The application has a inventory module where an employee can enter the desired stock for a certain product. To make the ordering process easier, I'm building a microflow that takes this desired amount and calculates how many times the product has to be ordered to meet the desired amount, and then present this in a list.

However, I'm having trouble checking if the product is on the order list already or not. Every time execute the microflow, the same product is added to the database over and over again. The microflow currently looks like this (sorry it's a bit messy but I had to fit it in the screenshot):

And my domain model is as follows:

EDIT: Here's the microflow on Model Share: https://modelshare.mendix.com/models/ff060751-c83b-478a-bb2a-3bb1c950add9/microflow

Any ideas? Thanks in advance!