根据店铺的订单量,进行销量排行
1.子查询方式
根据店铺的订单量
select sto_store.*,(SELECT count(so_order.order_id)as count FROM so_order where so_order.store_id =sto_store.store_id) as count FROM sto_store ORDER BY count desc
2.join方式
select sto_store.*,count(so_order.order_id)as count from sto_store join so_order on so_order.store_id = sto_store.store_id GROUP BY so_order.order_id ORDER BY count desc
具测试,在速度方面,子查询的方式比 join 的快一倍