import frappe


def execute():
    if frappe.db.has_column("Item", "thumbnail"):
        website_item = frappe.qb.DocType("Website Item").as_("wi")
        item = frappe.qb.DocType("Item")

        frappe.qb.update(website_item).inner_join(item).on(
            website_item.item_code == item.item_code
        ).set(
            website_item.thumbnail, item.thumbnail
        ).where(
            website_item.website_image.notnull()
            & website_item.thumbnail.isnull()
        ).run()