diff --git "a/40\345\274\240\350\200\200\344\273\201/0915\344\275\234\344\270\232.sql" "b/40\345\274\240\350\200\200\344\273\201/0915\344\275\234\344\270\232.sql"
new file mode 100644
index 0000000000000000000000000000000000000000..d04ca451afbbf139e3b6f816113eed184d9438fc
--- /dev/null
+++ "b/40\345\274\240\350\200\200\344\273\201/0915\344\275\234\344\270\232.sql"
@@ -0,0 +1,48 @@
+--创建数据库 DBTEST
+create database DBTEST;
+--使用数据库
+use dbtest;
+--部门信息表
+create table sectioninfo(
+	sectionID int primary key identity(1,1),
+	sectionName varchar(10) not null 
+);
+--员工信息表
+create table userinfo(
+	userNo int primary key  identity(1,1) not null,
+	userName varchar(10) not null unique check(len(userName)>4),
+	userSex varchar(2) not null default('男') check(userSex='男' or userSex='女'),
+	userAge int not null check(userAge between 1 and 100),
+	userAddress  varchar(50) default('湖北'),
+	userSection INT 
+);
+--员工考勤表
+create table workinfo(
+	workId int primary key identity(1,1),
+	userId  int references userinfo(userNo) not null ,
+	workTime datetime not null,
+	workDescription  varchar(40) not null check(workDescription in('迟到','早退','旷工','病假','事假'))
+);
+Alter table workInfo add constraint FK_workInfo_ClassId foreign key(userId) references userInfo(userNo);
+--增加数据
+insert into sectionInfo(sectionName) values
+	('开发部'),
+	('运行部'),
+	('人事部'),
+	('策划部'),
+	('管理部');
+select * from sectionInfo;
+insert into userInfo(userName,userSex,userAge,userAddress,userSection) values
+	('郑文源','男',8,'泉州',1),
+	('唐皓颖','男',9,'贵阳',2),
+	('袁贵森','女',25,'山西',3),
+	('小白','男',38,'未知',4),
+	('小黑','男',15,'未知',5);
+select * from userInfo;
+insert into workInfo(userId,workTime,workDescription) values
+	(1,'2022-01-05 15:25:46','迟到'),
+	(2,'2022-02-15 16:44:44','早退'),
+	(3,'2022-03-29 12:25:46','旷工'),
+	(4,'2022-04-25 08:45:46','病假'),
+	(5,'2022-06-18 19:25:46','事假');
+select * from workInfo;
\ No newline at end of file
diff --git "a/40\345\274\240\350\200\200\344\273\201/0918\344\275\234\344\270\232.sql" "b/40\345\274\240\350\200\200\344\273\201/0918\344\275\234\344\270\232.sql"
new file mode 100644
index 0000000000000000000000000000000000000000..ebf1aee7770fc08980360baa000a4dc69ad64bbc
--- /dev/null
+++ "b/40\345\274\240\350\200\200\344\273\201/0918\344\275\234\344\270\232.sql"
@@ -0,0 +1,81 @@
+--查询出巨蟹 6.22--7.22 的员工信息
+select * from People
+where datename(month,PeopleBirth) = 6 and day(PeopleBirth) between 22 and 30
+or datename(month,PeopleBirth) = 7 and day(PeopleBirth) between 1 and 22;
+
+
+--查询所有员工信息，添加一列显示属相(鼠,牛,虎,兔,龙,蛇,马,羊,猴,鸡,狗,猪)
+select *, case 
+when year(PeopleBirth)%12 = 0
+then '猴'
+when year(PeopleBirth)%12 = 1
+then '鸡'
+when year(PeopleBirth)%12 = 2
+then '狗'
+when year(PeopleBirth)%12 = 3
+then '猪'
+when year(PeopleBirth)%12 = 4
+then '鼠'
+when year(PeopleBirth)%12 = 5
+then '牛'
+when year(PeopleBirth)%12 = 6
+then '虎'
+when year(PeopleBirth)%12 = 7
+then '兔'
+when year(PeopleBirth)%12 = 8
+then '龙'
+when year(PeopleBirth)%12 = 9
+then '蛇'
+when year(PeopleBirth)%12 = 10
+then '马'
+when year(PeopleBirth)%12 = 11
+then '羊'
+end '生肖'
+from People 
+
+
+--1. 查询出武汉地区所有的员工信息，要求显示部门名称以及员工的详细资料
+select p.*,d.DepartmentName from People p
+inner join Department d 
+on p.DepartmentId = d.DepartmentId
+where p.PeopleAddress = '武汉';
+
+
+--2. 查询出武汉地区所有的员工信息，要求显示部门名称，职级名称以及员工的详细资料
+select p.*,d.DepartmentName,r.RankName from People p
+inner join Department d 
+on p.DepartmentId = d.DepartmentId
+inner join Rank r on r.RankId = p.RankId
+where p.PeopleAddress = '武汉';
+
+
+--3. 根据部门分组统计员工人数，员工工资总和，平均工资，最高工资和最低工资。
+select count(D.DepartmentName)部门员工人数,sum(p.PeopleSalary)员工工资总和,convert(decimal(10,2),
+avg(p.PeopleSalary))平均工资,max(p.PeopleSalary)最高工资,min(p.PeopleSalary)最低工资
+from People p
+inner join Department d
+on p.DepartmentId = d.DepartmentId
+group by d.DepartmentName
+
+
+--4. 根据部门分组统计员工人数，员工工资总和，平均工资，最高工资和最低工资，平均工资在10000 以下的不参与统计，
+--并且根据平均工资降序排列。
+select count(D.DepartmentName)部门员工人数,sum(p.PeopleSalary)员工工资总和,convert(decimal(10,2),
+avg(p.PeopleSalary))平均工资,max(p.PeopleSalary)最高工资,min(p.PeopleSalary)最低工资
+from People p
+inner join Department d
+on p.DepartmentId = d.DepartmentId
+group by d.DepartmentName
+having avg(p.PeopleSalary) > 10000
+order by 平均工资 desc
+
+
+--5. 根据部门名称，然后根据职位名称，分组统计员工人数，员工工资总和，平均工资，最高工资和最低工资
+select d.DepartmentName,r.RankName,count(*)员工人数,
+sum(p.PeopleSalary)员工工资总和,convert(decimal(10,2),
+avg(p.PeopleSalary))平均工资,max(p.PeopleSalary)最高工资,min(p.PeopleSalary)最低工资
+from People p
+inner join Department d 
+on p.DepartmentId = d.DepartmentId
+inner join Rank r on r.RankId = p.RankId
+group by d.DepartmentName,r.RankName
\ No newline at end of file
diff --git "a/\347\254\224\350\256\260/0916\347\254\224\350\256\260.sql" "b/\347\254\224\350\256\260/0916\347\254\224\350\256\260.sql"
new file mode 100644
index 0000000000000000000000000000000000000000..d39053cc4eb2cf8775a93d07db07c59cb15bb608
--- /dev/null
+++ "b/\347\254\224\350\256\260/0916\347\254\224\350\256\260.sql"
@@ -0,0 +1,86 @@
+--查询公司员工所在城市（不需要重复数据）
+--distinct
+select distinct PeopleAddress from People 
+
+--查询所有员工信息(根据工资排序(order by)，降序排列)
+select * from People order by PeopleSalary desc
+
+
+--查询1980年以后出生的员工信息
+select * from People where year(PeopleBirth)>=1980
+
+
+--查询出巨蟹 6.22--7.22 的员工信息
+
+--查询出和赵云在同一个城市的人
+
+
+select * from People where PeopleAddress=(select peopleAddress from People where PeopleName='赵云')
+
+--查询出电话号码开头138的员工信息,第4位可能是7，可能8 ，最后一个号码是5
+select * from people
+where PeoplePhone like '138[7-9]%5'  --789
+
+--查询出电话号码开头133的员工信息,第4位是2-5之间的数字 ，最后一个号码不是2和3
+select * from people
+where PeoplePhone like '138[2-5]%[^23]'
+
+
+--求出年龄比平均年龄高的人员信息
+--平均年龄：今年-出生年份
+select avg(year(getdate())-year(peoplebirth)) 平均年龄 from People
+
+select * from people where (year(getdate())-year(peoplebirth))>(select avg(year(getdate())-year(peoplebirth)) 平均年龄 from People)
+
+--平均工资
+select avg(PeopleSalary) 平均工资 from People
+
+--保留小数点后2位
+--round(小数,保留位数)
+select round(avg(PeopleSalary),2) 平均工资 from People
+
+--convert 02154.13200 decimal(5,2):保留小数后2位，有效数字总共是5
+
+--convert和cast 可以强制转换数据类型
+select convert(decimal(13,2),avg(PeopleSalary)) 平均工资 from People
+
+--cast
+select cast(avg(PeopleSalary) as decimal(13,2)) 平均工资 from People
+
+
+--根据员工所在地区分组统计员工人数，员工工资总和，平均工资，最高工资和最低工资，
+--要求筛选出员工人数至少在2人及以上的记录，并且1985年及以后出身的员工不参与统计。
+--count(*):空值也统计 count(字段)：当前字段的空值不统计
+select count(*) 员工人数,sum(PeopleSalary) 工资总和, max(PeopleSalary) 最高工资,min(PeopleSalary) 最低工资 from People 
+where year(PeopleBirth)<1985
+group by PeopleAddress
+having count(*)>=2
+
+
+--删除数据
+delete from People where PeopleName='蜗牛' 
+
+--删除
+--drop 删除整张表
+--truncate删除整张表，表还在
+
+--根据部门分组统计员工人数，员工工资总和，平均工资，最高工资和最低工资，平均工资在10000 以下的不参与统计，并且根据平均工资降序排列。
+select count(*) 员工人数, sum(PeopleSalary) 员工工资总和,convert(decimal(15,2),avg(PeopleSalary)) 平均工资 from Department de
+join People po on de.DepartmentId = po.DepartmentId
+group by po.DepartmentId having avg(PeopleSalary)>=10000
+order by 平均工资 desc
+
+create table B(
+	cid int primary key,
+	cname varchar(20)
+)
+
+
+create table A(
+	sid int,
+	sname varchar(10),
+	cid int references B(cid)
+)
+
+select * from A 
+left join B on A.cid=B.cid
\ No newline at end of file
diff --git "a/\347\254\224\350\256\260/2022-09-15-\345\273\272\345\272\223\345\273\272\350\241\250\347\272\246\346\235\237.sql" "b/\347\254\224\350\256\260/2022-09-15-\345\273\272\345\272\223\345\273\272\350\241\250\347\272\246\346\235\237.sql"
new file mode 100644
index 0000000000000000000000000000000000000000..526c95eeea0bdab3b3c359d4b5cc675ed24bdedc
--- /dev/null
+++ "b/\347\254\224\350\256\260/2022-09-15-\345\273\272\345\272\223\345\273\272\350\241\250\347\272\246\346\235\237.sql"
@@ -0,0 +1,78 @@
+--关系型数据库:SQL server, Mysql, Oracle 
+--创建数据库：create database 数据库名
+--database:数据库
+
+if exists (select * from sys.databases where name='DBTEST')
+ drop database DBTEST
+
+ create database DBTEST
+
+ --使用数据库
+ use dbtest
+
+ --创建班级表
+ create table ClassInfo(
+	ClassId int primary key identity(1,1),
+	ClassName varchar(20)
+ );
+
+ --插入数据： insert [into] 表名(字段名) values(值)
+ insert into ClassInfo( ClassName) values('软件1班');
+ 
+ insert ClassInfo values('软件2班')
+
+ select * from ClassInfo
+
+ --创建数据表
+ create table StuInfo(
+	stuId int primary key identity(1001,1),  --学生ID
+	--添加一个检查约束，判断用户插入/新增的数据，性别字段是不是男或者女
+	--default:默认约束
+	--check
+	stugender varchar(2) not null default('男') check(stugender='男' or stugender='女'),   --学生性别
+	stuphone char(11) check(len(stuphone)=11) unique,
+	--创建班级外键
+	--ClassID int references ClassInfo(ClassID)
+	ClassID int
+	
+ );
+
+
+ --增加外键
+ --修改表结构 表名 add constraint 约束名 foreign key(要引用的字段) references 主键表(字段)
+ Alter table StuInfo add constraint FK_StuInfo_ClassId foreign key(ClassID) references ClassInfo(ClassID)
+
+
+ --新增姓名列
+ alter table StuInfo add stuName varchar(20)
+
+
+
+ --如果没给出列名，默认是按照顺序一个个添加
+ --insert StuInfo values('女',13888888888)
+
+ --insert StuInfo(stuphone) values(15888888888)
+
+
+
+ select * from StuInfo;
+
+ --字符串：char(5),varchar(5),nvarchar(5)之间区别是什么
+
+
+
+ --删除表:drop table 表名
+ drop table StuInfo
+
+
+ --非空
+
+ --约束，自增(标识列)
+
+ --外键
+ --主键：默认唯一列
+ --默认
+ --唯一：
+ --check检查:
+
+ --插入数据：insert into
\ No newline at end of file