SELECT * FROM pop_order_info poi WHERE poi.is_delete = 0 and poi.vendor_id =7879 group by poi.order_sn--------+-------------+
| 1 | SIMPLE | poi | range | vendor_id_2,is_delete_vendor_id_order_sn,vendor_id | is_delete_vendor_id_order_sn | 5 | NULL | 15846