select * from goods where goodsid

in(select goodsid from orderdetails where orderid

in(select orderid from (select orderid from orders ORDER BY orderdate desc LIMIT 3) as a));

//最新外卖显示(显示外卖商品信息表的全部信息)

SELECT a.title,a.unitprice,a.discount,a.descrioption

FROM goods a,orderdetails b

WHERE a.goodsid=b.goodsid and qty=(SELECT max(qty) FROM orderdetails);

//畅销外卖显示

SELECT * FROM goods WHERE discount<1;

//活动外卖显示

SELECT * FROM goods WHERE title LIKE '%大盘鸡%';

//按照某关键字雨外卖标题的匹配查询外卖信息并显示

SELECT b.cateName,a.title,a.unitprice,a.discount,a.descrioption

FROM goods a INNER JOIN category b WHERE a.cateid=b.cateid GROUP BY cateName;

//按照外卖类型分类显示外卖信息

SELECT * FROM goods WHERE goodsid=2;

//用户点击某一个外卖，显示该外卖的详细信息

UPDATE goods SET like_title='1' WHERE goodsid=2;

//用户可以选择自己喜欢的外卖，放入购物车,(喜欢的放入购物车显示为‘1’)

SELECT * FROM goods WHERE like_title=1 and

EXISTS(SELECT * FROM customers WHERE custName='黄雅玲' AND loginpwd=234654);

//用户可以对购物车中的外卖下订单，下订单前需要先登录(输入用户名和密码)

SELECT * FROM orders

WHERE custid in(SELECT custid FROM customers

WHERE custName='黄雅玲' AND loginpwd=234654);

//用户登录可以查询自己的订单的情况，包括是否发货、商品在途情况、商品签收情况。

INSERT INTO goods(title,unitprice,packingexpense) VALUE('小鸡炖蘑菇','30.00','2');

//外卖基本信息录入

UPDATE goods SET roat=2 WHERE goodsid=2;

//外卖信息修改

UPDATE goods SET discount=0.75 WHERE goodsid=2;

//外卖销售折扣设置

SELECT * FROM orders WHERE orderstatus='已付款';

//订单发货

SELECT * FROM orders WHERE orderno=20110508001;

//订单信息查询

UPDATE customers SET account=1000 WHERE custname='黄雅玲';

//用户账户充值

UPDATE customers SET loginpwd='234654' WHERE custname='黄雅玲';

//用户密码修改