From 4657fde976277a1f6327ff15dda739f1798ed6ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=82=B9=E4=BA=A8=E4=BC=9F?= <529310475@qq.com>
Date: Fri, 17 Mar 2023 12:44:47 +0800
Subject: [PATCH] =?UTF-8?q?=E7=AC=AC=E5=85=AB=E6=AC=A1=E4=BD=9C=E4=B8=9A?=
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---
 .../20230317\344\275\234\344\270\232.md"      | 95 +++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 "11 \351\202\271\344\272\250\344\274\237/20230317\344\275\234\344\270\232.md"

diff --git "a/11 \351\202\271\344\272\250\344\274\237/20230317\344\275\234\344\270\232.md" "b/11 \351\202\271\344\272\250\344\274\237/20230317\344\275\234\344\270\232.md"
new file mode 100644
index 0000000..1cc687d
--- /dev/null
+++ "b/11 \351\202\271\344\272\250\344\274\237/20230317\344\275\234\344\270\232.md"	
@@ -0,0 +1,95 @@
+```
+create database wer charset utf8;
+use wer;
+CREATE TABLE `user`(
+	user_id int PRIMARY key,
+	user_name varchar(20),
+	user_tel varchar(20),
+	ordertime date
+);
+
+CREATE TABLE `order`(
+	order_id int,
+	user_id int,
+	type VARCHAR(20),
+	food VARCHAR(20),
+	number int,
+	price int,
+	FOREIGN KEY (user_id) REFERENCES `user`(user_id)
+);
+
+INSERT into `user` VALUES
+(1,'张三',19865645691,'2023-3-13'),
+(2,'李四',12345675691,'2023-3-13'),
+(3,'王五',12895678901,'2023-3-13'),
+(4,'老六',12345678691,'2023-3-14'),
+(5,'小七',18945678031,null), 
+(6,'老八',19345678561,'2023-3-16'),
+(7,'朱九',15845679911,null);
+
+INSERT INTO `order` VALUES
+(1,1,'快餐','肯德基全家桶',1,50),
+(2,1,'快餐','可乐',4,20),
+(3,6,'饮料','柠檬水',2,16),
+(4,2,'米饭','鱼香肉丝盖饭',5,60),
+(5,2,'饮料','珍珠奶茶',3,22),
+(6,3,'粉面类','螺蛳粉',4,28),
+(7,4,'粉面类','凉拌面',1,10);
+```
+
+-- 1.在用户表（user）新增一个性别字段user_sex，数据类型为char。
+alter table user add user_sex char;
+-- 2.由于顾客3退单，请把此订单删除。
+
+```
+delete from `order` where user_id = 3;
+```
+
+-- 3.老八的电话号码换新了，请将他的号码更新为8888888888。
+
+```
+update user set user_tel = 8888888888 where user_name = '老八';
+```
+
+-- 4.查询order表里的最高金额和总金额。
+
+```
+select max(price) 最高金额,SUM(price) from `order`;
+```
+
+-- 5.查询每个顾客分别订购了几个类别。
+
+```
+SELECT user_name,type from user LEFT JOIN `order` on user.user_id=`order`.user_id;
+```
+
+-- 6.查询饮料的总金额
+
+```
+select sum(price) from `order` where type='饮料'; 
+```
+
+-- 7.查询订单表（order）里的订单号，类别（type），食物（food）.
+
+```
+select `order_id` 订单号,type 类别,food 食物 from `order`;
+```
+
+-- 8.查询没吃饭的人的所有信息
+
+```
+SELECT * from user LEFT JOIN `order` on user.user_id=`order`.user_id where food is null;
+```
+
+-- 9.查询姓老的人的全部信息及订单信息
+
+```
+ SELECT * from user LEFT JOIN `order` on user.user_id=`order`.user_id where user_name like '老%';
+```
+
+-- 10.查询总金额大于20的订单里最大值的用户信息，使用降序排列。
+
+```
+ SELECT user.* from user LEFT JOIN `order` on user.user_id=`order`.user_id where price>20 and price=( SELECT max(price) from `order`) ORDER BY price desc;
+```
+
-- 
Gitee