Hi,
The column "product_parent_id" is include in the "tables.sql" file which is used during the first installation.
Otherwise, when you update HikaShop, some script and query are processed. You can see them into the file "install.hikashop.php".
If your column "product_parent_id" is missing, it is highly possible that other new columns are missing too (like "order_invoice_id" and "order_invoice_number").
Did you have problems during the HikaShop update ?
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.