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+## 第一题
+
+```mysql
+-- 1、创建数据库test01_market
+create database test01_market;
+use test01_market;
+-- 2、创建表格customers
+create table customers(
+c_num int,
+c_name varchar(50),
+c_contact VARCHAR(50),
+c_city varchar(50),
+c_birth date
+);
+-- | 字段名    | 数据类型    |
+-- | --------- | ----------- |
+-- | c_num     | int（11）   |
+-- | c_name    | varchar(50) |
+-- | c_contact | varchar(50) |
+-- | c_city    | varchar(50) |
+-- | c_birth   | date        |
+-- 
+-- **要求3：**将c_contact字段移动到c_birth字段后面
+alter table customers modify column c_contact varchar(50) after c_birth;
+-- **要求4：**将c_name字段数据类型改为 varchar(70)
+alter table customers modify c_name varchar(70) 
+-- **要求5：**将c_contact字段改名为c_phone
+alter table customers change c_contact c_phone varchar(50)
+-- **要求6：**增加c_gender字段到c_name后面，数据类型为char(1)
+alter table customers add c_gender varchar(1) after c_name
+-- **要求7：**将表名改为customers_info
+alter table customers rename customers_info
+-- **要求8：**删除字段c_city
+alter table customers_info drop c_city
+```
+
+## 第二题
+
+```mysql
+# 1、创建数据库test02_library
+create database test02_library
+# 2、创建表格books
+create table books(
+    b_id int,
+    b_name varchar(50),
+    authors varchar(100),
+    price float,
+    pudate year,
+    note varchar(100),
+    num int
+);
+# | 字段名  | 字段说明 | 数据类型      | 允许为空 | 唯一 |
+# | ------- | -------- | ------------- | -------- | ---- |
+# | b_id    | 书编号   | int(11)       | 否       | 是   |
+# | b_name  | 书名     | varchar（50） | 否       | 否   |
+# | authors | 作者     | varchar(100)  | 否       | 否   |
+# | price   | 价格     | float         | 否       | 否   |
+# | pubdate | 出版日期 | year          | 否       | 否   |
+# | note    | 说明     | varchar(100)  | 是       | 否   |
+# | num     | 库存     | int(11)       | 否       | 否   |
+#
+# 3、向books表中插入记录
+#
+# 1） 指定所有字段名称插入第一条记录
+insert into books (b_id, b_name, authors, price, pudate, note, num) values (1,'Tal of AAA','Dickes',23,1995,'noverl',11)
+# 2）不指定字段名称插入第二记录
+insert into books values (2,'EmmaT','Jane lura',35,1993,'jole',22);
+# 3）同时插入多条记录（剩下的所有记录）
+insert into books values (3,'Storty of Jane','Jane Tim',40,2001,'novel',0),
+(4,'Lovey Day ','George Byron',20,2005,'novel',30),
+(5,'Old land','Honore Blade',30,2010,'law',0),
+(6,'The Battle','Upto Sara',30,1999,'medicine',40),
+(7,'Rose Hood','Richard haggard',28,2008,'cartoon',28);
+# | b_id | b_name        | authors         | price | pubdate | note     | num  |
+# | ---- | ------------- | --------------- | ----- | ------- | -------- | ---- |
+# | 1    | Tal of AAA    | Dickes          | 23    | 1995    | novel    | 11   |
+# | 2    | EmmaT         | Jane lura       | 35    | 1993    | joke     | 22   |
+# | 3    | Story of Jane | Jane Tim        | 40    | 2001    | novel    | 0    |
+# | 4    | Lovey Day     | George Byron    | 20    | 2005    | novel    | 30   |
+# | 5    | Old land      | Honore Blade    | 30    | 2010    | law      | 0    |
+# | 6    | The Battle    | Upton Sara      | 30    | 1999    | medicine | 40   |
+# | 7    | Rose Hood     | Richard haggard | 28    | 2008    | cartoon  | 28   |
+#
+# 4、将小说类型(novel)的书的价格都增加5。
+update books set price=price+5 where note='novel';
+# 5、将名称为EmmaT的书的价格改为40。
+update books set price=40 where b_name='EmmaT';
+# 6、删除库存为0的记录
+delete from books where num=0;
+```
+
+## 第三题
+
+```mysql
+# 1、创建数据库test03_bookstore
+create database test03_bookstore;
+use test03_bookstore;
+
+# 2、创建book表
+create table book(
+    id int,
+    title varchar(100),
+    author varchar(100),
+    price double(11,2),
+    sales int,
+    stock int,
+    img_path varchar(100)
+);
+# ```mysql
+# +----------+--------------+------+-----+---------+----------------+
+# | Field    | Type         | Null | Key | Default | Extra          |
+# +----------+--------------+------+-----+---------+----------------+
+# | id       | int(11)      | NO   | PRI | NULL    | auto_increment |
+# | title    | varchar(100) | NO   |     | NULL    |                |
+# | author   | varchar(100) | NO   |     | NULL    |                |
+# | price    | double(11,2) | NO   |     | NULL    |                |
+# | sales    | int(11)      | NO   |     | NULL    |                |
+# | stock    | int(11)      | NO   |     | NULL    |                |
+# | img_path | varchar(100) | NO   |     | NULL    |                |
+# +----------+--------------+------+-----+---------+----------------+
+# ```
+#
+# 尝试添加部分模拟数据，参考示例如下：
+#
+# ```mysql
+# +----+-------------+------------+-------+-------+-------+----------------------------+
+# | id | title       | author     | price | sales | stock | img_path                   |
+# +----+-------------+------------+-------+-------+-------+-----------------------------+
+# |  1 | 解忧杂货店    | 东野圭吾   | 27.20 |   102 |    98 | upload/books/解忧杂货店.jpg   |
+# |  2 | 边城         | 沈从文     | 23.00 |   102 |    98 | upload/books/边城.jpg       |
+# +----+---------------+------------+-------+-------+-------+----------------------------+
+# ```
+insert into book values (1,'解忧杂货店','东野圭吾',27.20,102,98,'upload/books/解忧杂货店.jpg'),
+(2,'边城','沈从文',23.00,102,98,'upload/book/边城.jpg');
+
+# 3、创建用户表users，并插入数据
+create table users(
+    id int,
+    username varchar(100),
+    password varchar(100),
+    email varchar(100)
+);
+# ```mysql
+# +----------+--------------+------+-----+---------+----------------+
+# | Field    | Type         | Null | Key | Default | Extra          |
+# +----------+--------------+------+-----+---------+----------------+
+# | id       | int(11)      | NO   | PRI | NULL    | auto_increment |
+# | username | varchar(100) | NO   | UNI | NULL    |                |
+# | password | varchar(100) | NO   |     | NULL    |                |
+# | email    | varchar(100) | YES  |     | NULL    |                |
+# +----------+--------------+------+-----+---------+----------------+
+# ```
+#
+# 尝试添加部分模拟数据，参考示例如下：
+insert into users values(1,'admin',112233,'admin@mxdx.com');
+# ```mysql
+# +----+----------+----------------------------------+--------------------+
+# | id | username | password                         | email              |
+# +----+----------+----------------------------------+--------------------+
+# |  1 | admin    | 112233                           | admin@mxdx.com     |
+# +----+----------+----------------------------------+--------------------+
+# ```
+#
+# 4、创建订单表orders
+create table orders(
+  id varchar(100),
+  order_time datetime,
+  total_count int,
+  total_amount double(11,2),
+  state int,
+  user_id int
+);
+# ```mysql
+# +--------------+--------------+------+-----+---------+-------+
+# | Field        | Type         | Null | Key | Default | Extra |
+# +--------------+--------------+------+-----+---------+-------+
+# | id           | varchar(100) | NO   | PRI | NULL    |       |
+# | order_time   | datetime     | NO   |     | NULL    |       |
+# | total_count  | int(11)      | NO   |     | NULL    |       |
+# | total_amount | double(11,2) | NO   |     | NULL    |       |
+# | state        | int(11)      | NO   |     | NULL    |       |
+# | user_id      | int(11)      | NO   | MUL | NULL    |       |
+# +--------------+--------------+------+-----+---------+-------+
+# ```
+#
+# 尝试添加部分模拟数据，参考示例如下：
+insert into orders values('15294258455691','2018-06-20 00:30:45',2,50.20,0,1);
+# ```mysql
+# +----------------+---------------------+-------------+--------------+-------+---------+
+# | id             | order_time          | total_count | total_amount | state | user_id |
+# +----------------+---------------------+-------------+--------------+-------+---------+
+# | 15294258455691 | 2018-06-20 00:30:45 |           2 |        50.20 |     0 |       1 |
+# +----------------+---------------------+-------------+--------------+-------+---------+
+# ```
+#
+# 5、创建订单明细表order_items
+create table order_itms(
+    id int,
+    count int,
+    amount double(11,2),
+    title varchar(100),
+    author varchar(100),
+    price double(11,2),
+    img_path varchar(100),
+    order_id varchar(100)
+);
+# ```mysql
+# +----------+--------------+------+-----+---------+----------------+
+# | Field    | Type         | Null | Key | Default | Extra          |
+# +----------+--------------+------+-----+---------+----------------+
+# | id       | int(11)      | NO   | PRI | NULL    | auto_increment |
+# | count    | int(11)      | NO   |     | NULL    |                |
+# | amount   | double(11,2) | NO   |     | NULL    |                |
+# | title    | varchar(100) | NO   |     | NULL    |                |
+# | author   | varchar(100) | NO   |     | NULL    |                |
+# | price    | double(11,2) | NO   |     | NULL    |                |
+# | img_path | varchar(100) | NO   |     | NULL    |                |
+# | order_id | varchar(100) | NO   | MUL | NULL    |                |
+# +----------+--------------+------+-----+---------+----------------+
+# ```
+#
+# 尝试添加部分模拟数据，参考示例如下：
+insert into order_itms values (1,1,27.20,'解忧杂货店','东野圭吾',27.20,'static/img/default.jpg',15294258455691),
+(2,1,23.00,'边城','沈从文',23.00,'static/img/default.jpg',15294258455691);
+# ```mysql
+# +----+-------+--------+---------+---------+-------+----------------+----------------+
+# | id |count| amount| title    | author   | price | img_path       | order_id       |
+# +----+-------+--------+------------+----------+-------+----------------+----------------+
+# |  1 |   1 |  27.20| 解忧杂货店 | 东野圭吾 | 27.20 | static/img/default.jpg|15294258455691 |
+# |  2 |   1 |  23.00| 边城      | 沈从文   | 23.00 | static/img/default.jpg|15294258455691 |
+# +----+-------+--------+------------+----------+-------+------------+----------------+
+# ```
+#
+
+```
+