on orders.p_id=payments.p_id join employees
on orders.e_id=employees.e_id 方法2.
select orders.o_id,o_date,o_sum,p_mode,employees.e_name from orders,payments,employees
where orders.p_id=payments.p_id and orders.e_id=employees.e_id
课堂实践5 p134 子查询
1.用子查询了解“张小璐”处理的订单信息（订单号、订单时间、会员号、订单总额）
select o_id,o_date,c_id,o_sum from orders where e_id in (select e_id from employees
where employees.e_name='张小路')
2. 用子查询了解“张小璐”处理的订单信息（订单号、商品号、购买价格、购买数量）
select o_id,g_id,d_price,d_number from orderdetails where o_id in