Update id_supplier for a range of product references

[webbusiness23]

Hello,

 

i need to accomplish this (i'm using Prestashop 1.5.3.1):

I have an array of products that do not have assigned a supplier and i need to assign a supplier for them.

 

I tried this SQL code inside the ps_product_supplier table in phpmyadmin:

UPDATE `my_db_name`.`ps_product_supplier` SET `id_supplier` = '7' WHERE `ps_product_supplier`.`id_product` =354; 

 id_supplier='7' is a supplier i'm trying to use for the id_product=354 and i manually checked the supplier's id and the product's id and they both exist in Backoffice.

 

When i try to run the code, it says "0 rows affected".

 

How can i solve this? 

Thank you!