Here is the solution. Thanks to In case of multiple deletion, use below 2 query. note that run these SQL in same order as i have written here. First sql query will link orders to customers, and second query will show the orders in the customers account (orders tab) UPDATE sales_flat_order as SFO INNER JOIN customer_entity as C ON C.email = SFO.customer_email SET SFO.customer_id = C.entity_id WHERE SFO.customer_is_guest = 0 AND FOR sales_flat_order_grid Table UPDATE sales_flat_order_grid as SFOG INNER JOIN sales_flat_order as SFO ON SFO.entity_id = SFOG.entity_id SET SFOG.customer_id = SFO.customer_id