The relationship created in phpmyadmin table failed to show

Hi!

I have a product_info table and an inventory_record table. I created a relationship at phpmyadmin so that I can have a drop down under productName column in inventory_record table. The drop down content is from productName column in the product_info table. I tested in phpmyadmin, it looks fine. I can see and use the drop down. But, the drop down did not appear in the form.

Nevertheless, enum that I set in phpmyadmin (of the same table) do appear as a drop down in the form.

Any setting mistakes that I made to prevent that relationship to show up?

Thanks!