Hi,
There is a very similar request in that thread :
www.hikashop.com/forum/23-market-how-to/...o-vendor-orders.html
The HikaMarket order listing just use the table "hikashop order" and "hikashop user".
In order to include extra tables (for filters or search) requires for the moment the usage of a plugin.
Perform a link with the table "order product" would be complicated because the SQL will return one line per order product.
So if an order have 3 products, you would have 3 rows in the SQL result.
Because of the aggregation on the "order_id", you will right have one row but you can't know which one it would be.
To summarize, including the "order products" in the query is possible and could work for a search feature.
But it won't be the right usage if you want to display these order product information in the order listing afterwards.
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.