Sometimes, after a website or account transfer, your osCommerce may give a 1054 - Unknown column 'p.products_id' in 'on clause' error when browsing your products  or when using the search tool.

The most common reason for this issue is that your account has been moved from a server running MySQL 4 to a server running MySQL 5.

As a solution, you can try applying this osCommerce contribution.

In most cases, this will resolve the 1054 problem. If, however, the problem persists, the best solution would be to have your account  migrated to a server running MySQL 4.

If you are a SiteGround customer, you can request this migration by posting a support ticket.