From 7e8a68bcc6f950c91777c5bb4e9a62367e394c81 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Thu, 15 Sep 2022 16:51:51 +0000
Subject: [PATCH 01/13] =?UTF-8?q?=E6=96=B0=E5=BB=BA=20=E8=A2=81=E8=B4=B5?=
 =?UTF-8?q?=E6=A3=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256/.keep" | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 "\350\242\201\350\264\265\346\243\256/.keep"

diff --git "a/\350\242\201\350\264\265\346\243\256/.keep" "b/\350\242\201\350\264\265\346\243\256/.keep"
new file mode 100644
index 0000000..e69de29
-- 
Gitee


From 3561de904cce02e8d1ba3a9df9d663ecb0d28264 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Thu, 15 Sep 2022 16:52:41 +0000
Subject: [PATCH 02/13] 28
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 袁贵森 <3032059138@qq.com>
---
 "\350\242\201\350\264\265\346\243\256/28.sql" | 52 +++++++++++++++++
 .../\347\254\224\350\256\260.txt"             | 58 +++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 "\350\242\201\350\264\265\346\243\256/28.sql"
 create mode 100644 "\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256/28.sql" "b/\350\242\201\350\264\265\346\243\256/28.sql"
new file mode 100644
index 0000000..9f2be17
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256/28.sql"
@@ -0,0 +1,52 @@
+--判断数据库是否存在
+if exists (select * from sys.databases where name='DBTEXT')
+drop database DBTEXT;
+--创建数据库
+create database DBTEXT
+--使用数据库
+
+
+--创建数据表
+--primary key 主键
+--identity 自增(标识符)
+--default 默约束
+--check 检查
+
+--部门信息表
+create table sectionInfo(
+	 sectionID int primary key identity(2010,1),
+	sectionName varchar(10) not null
+);
+
+INSERT into sectionInfo (sectionName) VALUES ('张三','李四','全网','暗属性出','认为对方','违法的'),
+--员工信息表
+create table userInfo(
+	userNo int identity(1000,1) primary key not null,
+	userName varchar(10)  not null check(len(userName)>4) unique,
+	userSex varchar(2) not null check(userSex='男' or userSex='女'),
+	userAge int not null check(userAge between 1 and 100),
+	userAddress varchar(50) default ('湖北'),
+	userSection  int
+); 
+Alter table sectionInfo add constraint FK_sectionInfo_ClassId foreign key(userSection) references asd(sectionID);
+INSERT into userInfo (userName,userSex,userAge,userAddress,userSection) VALUES
+('张三','男',19,'湖南',1),
+('张嘶','女',20,'福建',2),
+('张无','女',17,'广东',1),
+('张六','男',19,'湖北',2),
+('张气','男',17,'湖南',1)
+--员工考勤表
+create table workInfo(
+	workId int identity(1,1) primary key not null,
+	userId int  not null,
+	workTime datetime not null,
+	workDescription varchar (40) not null check(workDescription='迟到' or workDescription='早退' or workDescription='旷工' or workDescription='病假' or workDescription='事假')
+);
+Alter table workInfo add constraint FK_workInfo_ClassId foreign key(userId) references sectionInfo(userNo);
+
+INSERT into workInfo (workTime,workDescription) VALUES
+('2021-09-05','早退'),
+('2022-08-06','迟到'),
+('2023-09-10','事假'),
+('2020-09-20','旷工'),
+('2021-10-05','病假')
\ No newline at end of file
diff --git "a/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
new file mode 100644
index 0000000..3631665
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
@@ -0,0 +1,58 @@
+--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;
\ No newline at end of file
-- 
Gitee


From 00bf9b61a366a00919c3adad29288ae7af8b7b59 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:47:25 +0000
Subject: [PATCH 03/13] =?UTF-8?q?=E6=96=B0=E5=BB=BA=20=E8=A2=81=E8=B4=B5?=
 =?UTF-8?q?=E6=A3=AE.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256./.keep" | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 "\350\242\201\350\264\265\346\243\256./.keep"

diff --git "a/\350\242\201\350\264\265\346\243\256./.keep" "b/\350\242\201\350\264\265\346\243\256./.keep"
new file mode 100644
index 0000000..e69de29
-- 
Gitee


From 9142522e99f667acd88871313f441197ca3a42c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:47:46 +0000
Subject: [PATCH 04/13] 28
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 袁贵森 <3032059138@qq.com>
---
 .../SQLQuery1.sql"                            | 299 ++++++++++++++++++
 .../\347\254\224\350\256\260.txt"             | 111 +++++++
 2 files changed, 410 insertions(+)
 create mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
 create mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
new file mode 100644
index 0000000..0231695
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
@@ -0,0 +1,299 @@
+if exists(select * from sys.databases where name='DBTEST')
+drop database DBTEST;
+go
+
+create database DBTEST;
+go
+
+use DBTEST;
+go
+
+--�������ű�
+create table Department 
+(
+	--�������ű��;int������������;primary key��������;identity(1,1)������1��ʼ����Ϊ1������;
+	DepartmentId int primary key identity(1,1),
+	--������������;nvarchar(50)��������50���ַ���;not null��������Ϊ��;
+	DepartmentName nvarchar(50) not null,
+	--��������������text�������ı�;
+	DepartmentRemark text
+);
+go
+
+--����ְ������rankΪϵͳ�ؼ��֣��˴�ʹ��[]�����Զ������֣�����ϵͳ�ؼ���
+create table [Rank]
+(
+	RankId int primary key identity(1,1),
+	RankName nvarchar(50) not null,
+	RankRemark text
+);
+go
+
+--����Ա����Ϣ��
+create table People
+(
+	PeopleId int primary key identity(1,1),
+	--references�����������,���ֶα�������������������Լ��
+	DepartmentId int references Department(DepartmentId)  not null,
+	RankId int references [Rank](RankId) not null,
+	PeopleName nvarchar(50) not null,
+	--default�����ֶ�Ĭ��ֵ; check���Թ涨�ֶ�ֵ��Լ������;
+	PeopleSex nvarchar(1) default('��') check(PeopleSex='��' or PeopleSex='Ů') not null,
+	PeopleBirth datetime not null,
+	PeopleSalary decimal(12,2) check(PeopleSalary>= 1000 and PeopleSalary <= 100000) not null,
+	--unique����ΨһԼ����Ϊ�����ṩΨһ�Ա�֤;
+	PeoplePhone nvarchar(20) unique not null,
+	PeopleAddress nvarchar(100),
+	--datetime��smalldatetime�����Ա�ʾʱ�����ͣ�getdate()���ڻ�ȡϵͳ��ǰʱ��
+	PeopleAddTime smalldatetime default(getdate())
+);
+go
+
+
+
+------------------------------�������ݲ���------------------------------
+--���ű���������
+insert into Department values('������','��˾�������������IJ���');
+go
+
+--һ���Բ����������
+insert into Department(DepartmentName,DepartmentRemark)
+select '�г���','��ţ�IJ���' union
+select '��Ʒ��','�����ǿյIJ���' union
+select '�ܾ���','�����쵼�IJ���' ;
+go
+
+-------ְ������������
+insert into [Rank](RankName,RankRemark)
+values('����','�����������������')
+insert into [Rank](RankName,RankRemark)
+values('�м�','�߱������������������')
+insert into [Rank](RankName,RankRemark)
+values('�߼�','�߱����Դ���ȫ�����������');
+go
+
+---------��Ա������������
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,3,'����','��','1984-7-9',20000,'13554785452','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'������','Ů','1987-7-9',15000,'13256854578','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'����','��','1988-8-8',12000,'13985745871','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'�ŷ�','��','1990-8-8',8000,'13535987412','�˲�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'����','��','1989-4-8',9000,'13845789568','�˲�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'����','��','1995-4-8',9500,'13878562568','���',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'�Ƹ�','��','1989-4-20',8500,'13335457412','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,1,'����','Ů','1989-4-20',6500,'13437100050','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,2,'�ܲ�','��','1987-12-20',25000,'13889562354','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'����','��','1981-11-11',9000,'13385299632','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'��Τ','��','1978-1-13',8000,'13478545263','�Ϻ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'����','��','1998-12-12',7500,'13878523695','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,3,'���','��','1968-11-22',9000,'13698545841','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'���','��','1988-1-22',11000,'13558745874','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'��Ȩ','��','1990-2-21',12000,'13698745214','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'����','Ů','1995-2-21',13000,'13985478512','�Ϻ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'С��','Ů','1996-2-21',13500,'13778787874','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'���','��','1992-10-11',8000,'13987455214','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'³��','��','1984-9-10',5500,'13254785965','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'����','��','1987-5-19',8500,'13352197364','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'½ѷ','��','1996-5-19',7500,'13025457392','�Ͼ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'̫ʷ��','��','1983-6-1',7500,'13077778888','�Ϻ�',getdate())
+
+
+---��ѯ
+select * from Department
+select * from [Rank]
+select * from People 
+
+
+--1. ��ѯ������������
+
+--2. ָ���в�ѯ���������Ա���н���绰��
+select PeopleName as ���� ,Peoplesex as �Ա� from People;
+--3. ָ���в�ѯ,���Զ��������������������Ա���н���绰��
+--4. ��ѯ��˾Ա�����ڳ��У�����Ҫ�ظ����ݣ�
+
+--�����ظ��У�distinct
+select distinct peopleAddress from People; 
+--5. ���蹤���յ�10%����ѯԭʼ���ʺ͵�����Ĺ��ʣ���ʾ���������Ա���н����н�����н���������в�ѯ����
+select top 3 PeopleName ����, PeopleSalary ��н, PeopleSalary*1.1 ��н����н from People;
+
+--top ordey by
+
+
+select * from People 
+--����ָ���У��������Ա���н���绰����ѯ�Ա�ΪŮ��Ա����Ϣ,���Զ�����������
+--2. ��ѯ��н���ڵ���10000 ��Ա����Ϣ( ������ )
+--3. ��ѯ��н���ڵ���10000 ��ŮԱ����Ϣ(������)
+select * from People where PeopleSalary>=10000 and PeopleSex='Ů'
+--4. ��ʾ����������1980-1-1֮�󣬶�����н���ڵ���10000��ŮԱ����Ϣ��
+select * from People  where PeopleSalary>=10000 and PeopleSex='Ů' and PeopleBirth>'1995-1-1';  
+
+--5. ��ʾ����н���ڵ���15000 ��Ա��,������н���ڵ���8000��ŮԱ����Ϣ��
+select * from People where (PeopleSalary>=8000 and peoplesex='Ů') or PeopleSalary>=15000 
+--6. ��ѯ��н��10000-20000 ֮��Ա����Ϣ( ������ )
+select * from People where PeopleSalary between 10000 and 20000
+--7. ��ѯ����ַ�ڱ��������Ϻ���Ա����Ϣ
+--8. ��ѯ����Ա����Ϣ(���ݹ������򣬽�������): asc��Ĭ�ϣ�:����  desc:����
+select * from People order by PeopleSalary desc
+
+--9. ��ʾ���е�Ա����Ϣ���������ֵij��Ƚ��е�������
+--10. ��ѯ������ߵ�5���˵���Ϣ
+select top 5 * from People order by PeopleSalary desc
+--11. ��ѯ������ߵ�10%��Ա����Ϣ
+select top 10 percent *  from People order by PeopleSalary desc
+--12. ��ѯ����ַû����д��Ա����Ϣ
+--Ϊ�ղ�����=��is null, is not null
+select * from People where PeopleAddress is null;
+
+--13. ��ѯ����ַ�Ѿ���д��Ա����Ϣ
+--14. ��ѯ���е�80��Ա����Ϣ
+
+--15. ��ѯ������30-40 ֮�䣬���ҹ�����15000-30000 ֮���Ա����Ϣ
+--16. ��ѯ����з 6.22--7.22 ��Ա����Ϣ
+select * from people where 
+(MONTH(PeopleBirth)=6 and DAY(PeopleBirth)>=22) or  
+(MONTH(PeopleBirth)=7 and DAY(PeopleBirth)<=22)
+;
+--17. ��ѯ���ʱ����Ƹߵ���
+select * from people where PeopleSalary > 9000
+--18. ��ѯ����������ͬһ�����е���
+--19. ��ѯ����ФΪ�����Ա��Ϣ
+--20. ��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
+--case when end
+
+--��ѯ����з 6.22--7.22 ��Ա����Ϣ
+select * from People where
+(MONTH(PeopleBirth) = 6  and DAY(PeopleBirth) >=22) or
+(MONTH(PeopleBirth) = 7  and DAY(PeopleBirth) <=22)
+
+--1. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ���������Լ�Ա������ϸ����
+select p.*,d.DepartmentName �������� from People p
+inner join Department d on p.DepartmentId=d.DepartmentId
+where p.PeopleAddress='�人'
+
+
+--2. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ�������ƣ�ְ�������Լ�Ա������ϸ����
+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='�人'
+
+--3. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʡ�
+select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
+inner join Department d on d.DepartmentId=p.DepartmentId
+group by d.DepartmentId
+
+--4. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʣ�ƽ��������10000 ���µIJ�����ͳ�ƣ�
+--���Ҹ���ƽ�����ʽ������С�
+select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
+inner join Department d on d.DepartmentId=p.DepartmentId
+group by d.DepartmentId
+having convert(decimal(15,2),avg(PeopleSalary))>=10000
+order by ƽ������ desc
+
+--5. ���ݲ������ƣ�Ȼ�����ְλ���ƣ�����ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹���
+select [Rank].RankName ְλ����,count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,
+min(PeopleSalary) ��͹��� from Department
+inner join People on People.DepartmentId=Department.DepartmentId
+inner join [Rank] on People.RankId=[Rank].RankId
+group by [Rank].RankName
+
+--��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
+select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
+case 
+when  year(PeopleBirth) % 12 = 1 then '��'
+when  year(PeopleBirth) % 12 = 2 then 'ţ'
+when  year(PeopleBirth) % 12 = 3 then '��'
+when  year(PeopleBirth) % 12 = 4 then '��'
+when  year(PeopleBirth) % 12 = 5 then '��'
+when  year(PeopleBirth) % 12 = 6 then '��'
+when  year(PeopleBirth) % 12 = 7 then '��'
+when  year(PeopleBirth) % 12 = 8 then '��'
+when  year(PeopleBirth) % 12 = 9 then '��'
+when  year(PeopleBirth) % 12 = 10 then '��'
+when  year(PeopleBirth) % 12 = 11 then '��'
+when  year(PeopleBirth) % 12 = 0 then '��'
+else ''
+end "��Ф"
+from People 
+
+select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
+case
+    when year(PeopleBirth) % 12 = 4 then '��'
+    when year(PeopleBirth) % 12 = 5 then 'ţ'
+    when year(PeopleBirth) % 12 = 6 then '��'
+    when year(PeopleBirth) % 12 = 7 then '��'
+    when year(PeopleBirth) % 12 = 8 then '��'
+    when year(PeopleBirth) % 12 = 9 then '��'
+    when year(PeopleBirth) % 12 = 10 then '��'
+    when year(PeopleBirth) % 12 = 11 then '��'
+    when year(PeopleBirth) % 12 = 0 then '��'
+    when year(PeopleBirth) % 12 = 1 then '��'
+    when year(PeopleBirth) % 12 = 2 then '��'
+    when year(PeopleBirth) % 12 = 3 then '��'
+    ELSE ''
+end ��Ф
+from People
\ No newline at end of file
diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
new file mode 100644
index 0000000..d318cf7
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
@@ -0,0 +1,111 @@
+**SQL中常用运算符**
+
+```sql
+=：等于，比较是否相等及赋值
+!=：比较不等于
+>：比较大于
+<：比较小于
+>=：比较大于等于
+<=：比较小于等于
+IS NULL：比较为空
+IS NOT NULL：比较不为空
+in：比较是否在其中
+like：模糊查询
+BETWEEN...AND...：比较是否在两者之间 50-100   BETWEEN 50 AND 100
+and：逻辑与（两个条件同时成立表达式成立）
+or：逻辑或（两个条件有一个成立表达式成立） 
+not：逻辑非（条件成立，表达式则不成立；条件不成立，表达式则成立）
+```
+#### 模糊查询
+
+模糊查询使用like关键字和通配符结合来实现，通配符具体含义如下：
+
+```sql
+%：代表匹配0个字符、1个字符或多个字符。
+_：代表匹配有且只有1个字符。
+[]：代表匹配范围内
+[^]：代表匹配不在范围内
+```
+#### 聚合函数
+
+SQL SERVER中聚合函数主要有：
+
+```sql
+count:求数量
+max:求最大值
+min:求最小值
+sum:求和
+avg:求平均值
+```
+ROUND函数用法：
+
+```sql
+round(num,len,[type])
+其中:
+num表示需要处理的数字，len表示需要保留的长度，type处理类型(0是默认值代表四舍五入，非0代表直接截取)
+select ROUND(123.45454,3)  --123.45500
+select ROUND(123.45454,3,1) --123.45400
+
+CONVERT()与CAST()函数:
+
+```sql
+--1.保留小数
+convert(decimal(13,2),12.45454)
+cast(12.45454 as decimal(13,2))
+--2.强制转换类型
+```
+
+
+
+#### SQL中常用的时间函数
+
+```sql
+select DATEDIFF(day, '2019-08-20', getDate());    --获取指定时间单位的差值
+SELECT DATEADD(MINUTE,-5,GETDATE())               --加减时间,此处为获取五分钟前的时间,MINUTE 表示分钟，可为 YEAR,MONTH,DAY,HOUR
+select DATENAME(month, getDate());                --当前月份
+select DATENAME(WEEKDAY, getDate());              --当前星期几
+select DATEPART(month, getDate());                --当前月份
+select DAY(getDate());                            --返回当前日期天数
+select MONTH(getDate());                          --返回当前日期月数
+select YEAR(getDate());                           --返回当前日期年数
+
+SELECT CONVERT(VARCHAR(22),GETDATE(),20)          --2020-01-09 14:46:46
+SELECT CONVERT(VARCHAR(24),GETDATE(),21)          --2020-01-09 14:46:55.91
+SELECT CONVERT(VARCHAR(22),GETDATE(),23)		  --2020-01-09
+SELECT CONVERT(VARCHAR(22),GETDATE(),24)          --15:04:07
+Select CONVERT(varchar(20),GETDATE(),14)          --15:05:49:330
+```
+
+**时间格式控制字符串：**
+
+| 名称         | 日期单位    | 缩写      |
+| ------------ | ----------- | --------- |
+| 年           | year        | yyyy 或yy |
+| 季度         | quarter     | qq,q      |
+| 月           | month       | mm,m      |
+| 一年中第几天 | dayofyear   | dy,y      |
+| 日           | day         | dd,d      |
+| 一年中第几周 | week        | wk,ww     |
+| 星期         | weekday     | dw        |
+| 小时         | Hour        | hh        |
+| 分钟         | minute      | mi,n      |
+| 秒           | second      | ss,s      |
+| 毫秒         | millisecond | ms        |
+
+SQL语句执行顺序:
+
+```sql
+(7)     SELECT 
+(8)     DISTINCT <select_list>
+(1)     FROM <left_table>
+(3)     <join_type> JOIN <right_table>
+(2)     ON <join_condition>
+(4)     WHERE <where_condition>
+(5)     GROUP BY <group_by_list>
+(6)     HAVING <having_condition>
+(9)     ORDER BY <order_by_condition>
+(10)    LIMIT <limit_number>
+```
+
+
+
-- 
Gitee


From d1ef056fef69932f8f9ccfa985f8df4628bfe052 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:48:42 +0000
Subject: [PATCH 05/13] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=20?=
 =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE./=E8=A2=81=E8=B4=B5=E6=A3=AE/SQLQue?=
 =?UTF-8?q?ry1.sql?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../SQLQuery1.sql"                            | 299 ------------------
 1 file changed, 299 deletions(-)
 delete mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"

diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
deleted file mode 100644
index 0231695..0000000
--- "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
+++ /dev/null
@@ -1,299 +0,0 @@
-if exists(select * from sys.databases where name='DBTEST')
-drop database DBTEST;
-go
-
-create database DBTEST;
-go
-
-use DBTEST;
-go
-
---�������ű�
-create table Department 
-(
-	--�������ű��;int������������;primary key��������;identity(1,1)������1��ʼ����Ϊ1������;
-	DepartmentId int primary key identity(1,1),
-	--������������;nvarchar(50)��������50���ַ���;not null��������Ϊ��;
-	DepartmentName nvarchar(50) not null,
-	--��������������text�������ı�;
-	DepartmentRemark text
-);
-go
-
---����ְ������rankΪϵͳ�ؼ��֣��˴�ʹ��[]�����Զ������֣�����ϵͳ�ؼ���
-create table [Rank]
-(
-	RankId int primary key identity(1,1),
-	RankName nvarchar(50) not null,
-	RankRemark text
-);
-go
-
---����Ա����Ϣ��
-create table People
-(
-	PeopleId int primary key identity(1,1),
-	--references�����������,���ֶα�������������������Լ��
-	DepartmentId int references Department(DepartmentId)  not null,
-	RankId int references [Rank](RankId) not null,
-	PeopleName nvarchar(50) not null,
-	--default�����ֶ�Ĭ��ֵ; check���Թ涨�ֶ�ֵ��Լ������;
-	PeopleSex nvarchar(1) default('��') check(PeopleSex='��' or PeopleSex='Ů') not null,
-	PeopleBirth datetime not null,
-	PeopleSalary decimal(12,2) check(PeopleSalary>= 1000 and PeopleSalary <= 100000) not null,
-	--unique����ΨһԼ����Ϊ�����ṩΨһ�Ա�֤;
-	PeoplePhone nvarchar(20) unique not null,
-	PeopleAddress nvarchar(100),
-	--datetime��smalldatetime�����Ա�ʾʱ�����ͣ�getdate()���ڻ�ȡϵͳ��ǰʱ��
-	PeopleAddTime smalldatetime default(getdate())
-);
-go
-
-
-
-------------------------------�������ݲ���------------------------------
---���ű���������
-insert into Department values('������','��˾�������������IJ���');
-go
-
---һ���Բ����������
-insert into Department(DepartmentName,DepartmentRemark)
-select '�г���','��ţ�IJ���' union
-select '��Ʒ��','�����ǿյIJ���' union
-select '�ܾ���','�����쵼�IJ���' ;
-go
-
--------ְ������������
-insert into [Rank](RankName,RankRemark)
-values('����','�����������������')
-insert into [Rank](RankName,RankRemark)
-values('�м�','�߱������������������')
-insert into [Rank](RankName,RankRemark)
-values('�߼�','�߱����Դ���ȫ�����������');
-go
-
----------��Ա������������
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,3,'����','��','1984-7-9',20000,'13554785452','�ɶ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,2,'������','Ů','1987-7-9',15000,'13256854578','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,1,'����','��','1988-8-8',12000,'13985745871','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,1,'�ŷ�','��','1990-8-8',8000,'13535987412','�˲�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,3,'����','��','1989-4-8',9000,'13845789568','�˲�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,3,'����','��','1995-4-8',9500,'13878562568','���',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,2,'�Ƹ�','��','1989-4-20',8500,'13335457412','�人',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,1,'����','Ů','1989-4-20',6500,'13437100050','�人',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,2,'�ܲ�','��','1987-12-20',25000,'13889562354','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,3,'����','��','1981-11-11',9000,'13385299632','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,1,'��Τ','��','1978-1-13',8000,'13478545263','�Ϻ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,1,'����','��','1998-12-12',7500,'13878523695','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,3,'���','��','1968-11-22',9000,'13698545841','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,3,'���','��','1988-1-22',11000,'13558745874','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,2,'��Ȩ','��','1990-2-21',12000,'13698745214','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,2,'����','Ů','1995-2-21',13000,'13985478512','�Ϻ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,1,'С��','Ů','1996-2-21',13500,'13778787874','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,2,'���','��','1992-10-11',8000,'13987455214','�人',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,3,'³��','��','1984-9-10',5500,'13254785965','�ɶ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,3,'����','��','1987-5-19',8500,'13352197364','�ɶ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,1,'½ѷ','��','1996-5-19',7500,'13025457392','�Ͼ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,2,'̫ʷ��','��','1983-6-1',7500,'13077778888','�Ϻ�',getdate())
-
-
----��ѯ
-select * from Department
-select * from [Rank]
-select * from People 
-
-
---1. ��ѯ������������
-
---2. ָ���в�ѯ���������Ա���н���绰��
-select PeopleName as ���� ,Peoplesex as �Ա� from People;
---3. ָ���в�ѯ,���Զ��������������������Ա���н���绰��
---4. ��ѯ��˾Ա�����ڳ��У�����Ҫ�ظ����ݣ�
-
---�����ظ��У�distinct
-select distinct peopleAddress from People; 
---5. ���蹤���յ�10%����ѯԭʼ���ʺ͵�����Ĺ��ʣ���ʾ���������Ա���н����н�����н���������в�ѯ����
-select top 3 PeopleName ����, PeopleSalary ��н, PeopleSalary*1.1 ��н����н from People;
-
---top ordey by
-
-
-select * from People 
---����ָ���У��������Ա���н���绰����ѯ�Ա�ΪŮ��Ա����Ϣ,���Զ�����������
---2. ��ѯ��н���ڵ���10000 ��Ա����Ϣ( ������ )
---3. ��ѯ��н���ڵ���10000 ��ŮԱ����Ϣ(������)
-select * from People where PeopleSalary>=10000 and PeopleSex='Ů'
---4. ��ʾ����������1980-1-1֮�󣬶�����н���ڵ���10000��ŮԱ����Ϣ��
-select * from People  where PeopleSalary>=10000 and PeopleSex='Ů' and PeopleBirth>'1995-1-1';  
-
---5. ��ʾ����н���ڵ���15000 ��Ա��,������н���ڵ���8000��ŮԱ����Ϣ��
-select * from People where (PeopleSalary>=8000 and peoplesex='Ů') or PeopleSalary>=15000 
---6. ��ѯ��н��10000-20000 ֮��Ա����Ϣ( ������ )
-select * from People where PeopleSalary between 10000 and 20000
---7. ��ѯ����ַ�ڱ��������Ϻ���Ա����Ϣ
---8. ��ѯ����Ա����Ϣ(���ݹ������򣬽�������): asc��Ĭ�ϣ�:����  desc:����
-select * from People order by PeopleSalary desc
-
---9. ��ʾ���е�Ա����Ϣ���������ֵij��Ƚ��е�������
---10. ��ѯ������ߵ�5���˵���Ϣ
-select top 5 * from People order by PeopleSalary desc
---11. ��ѯ������ߵ�10%��Ա����Ϣ
-select top 10 percent *  from People order by PeopleSalary desc
---12. ��ѯ����ַû����д��Ա����Ϣ
---Ϊ�ղ�����=��is null, is not null
-select * from People where PeopleAddress is null;
-
---13. ��ѯ����ַ�Ѿ���д��Ա����Ϣ
---14. ��ѯ���е�80��Ա����Ϣ
-
---15. ��ѯ������30-40 ֮�䣬���ҹ�����15000-30000 ֮���Ա����Ϣ
---16. ��ѯ����з 6.22--7.22 ��Ա����Ϣ
-select * from people where 
-(MONTH(PeopleBirth)=6 and DAY(PeopleBirth)>=22) or  
-(MONTH(PeopleBirth)=7 and DAY(PeopleBirth)<=22)
-;
---17. ��ѯ���ʱ����Ƹߵ���
-select * from people where PeopleSalary > 9000
---18. ��ѯ����������ͬһ�����е���
---19. ��ѯ����ФΪ�����Ա��Ϣ
---20. ��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
---case when end
-
---��ѯ����з 6.22--7.22 ��Ա����Ϣ
-select * from People where
-(MONTH(PeopleBirth) = 6  and DAY(PeopleBirth) >=22) or
-(MONTH(PeopleBirth) = 7  and DAY(PeopleBirth) <=22)
-
---1. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ���������Լ�Ա������ϸ����
-select p.*,d.DepartmentName �������� from People p
-inner join Department d on p.DepartmentId=d.DepartmentId
-where p.PeopleAddress='�人'
-
-
---2. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ�������ƣ�ְ�������Լ�Ա������ϸ����
-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='�人'
-
---3. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʡ�
-select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
-inner join Department d on d.DepartmentId=p.DepartmentId
-group by d.DepartmentId
-
---4. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʣ�ƽ��������10000 ���µIJ�����ͳ�ƣ�
---���Ҹ���ƽ�����ʽ������С�
-select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
-inner join Department d on d.DepartmentId=p.DepartmentId
-group by d.DepartmentId
-having convert(decimal(15,2),avg(PeopleSalary))>=10000
-order by ƽ������ desc
-
---5. ���ݲ������ƣ�Ȼ�����ְλ���ƣ�����ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹���
-select [Rank].RankName ְλ����,count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,
-min(PeopleSalary) ��͹��� from Department
-inner join People on People.DepartmentId=Department.DepartmentId
-inner join [Rank] on People.RankId=[Rank].RankId
-group by [Rank].RankName
-
---��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
-select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
-case 
-when  year(PeopleBirth) % 12 = 1 then '��'
-when  year(PeopleBirth) % 12 = 2 then 'ţ'
-when  year(PeopleBirth) % 12 = 3 then '��'
-when  year(PeopleBirth) % 12 = 4 then '��'
-when  year(PeopleBirth) % 12 = 5 then '��'
-when  year(PeopleBirth) % 12 = 6 then '��'
-when  year(PeopleBirth) % 12 = 7 then '��'
-when  year(PeopleBirth) % 12 = 8 then '��'
-when  year(PeopleBirth) % 12 = 9 then '��'
-when  year(PeopleBirth) % 12 = 10 then '��'
-when  year(PeopleBirth) % 12 = 11 then '��'
-when  year(PeopleBirth) % 12 = 0 then '��'
-else ''
-end "��Ф"
-from People 
-
-select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
-case
-    when year(PeopleBirth) % 12 = 4 then '��'
-    when year(PeopleBirth) % 12 = 5 then 'ţ'
-    when year(PeopleBirth) % 12 = 6 then '��'
-    when year(PeopleBirth) % 12 = 7 then '��'
-    when year(PeopleBirth) % 12 = 8 then '��'
-    when year(PeopleBirth) % 12 = 9 then '��'
-    when year(PeopleBirth) % 12 = 10 then '��'
-    when year(PeopleBirth) % 12 = 11 then '��'
-    when year(PeopleBirth) % 12 = 0 then '��'
-    when year(PeopleBirth) % 12 = 1 then '��'
-    when year(PeopleBirth) % 12 = 2 then '��'
-    when year(PeopleBirth) % 12 = 3 then '��'
-    ELSE ''
-end ��Ф
-from People
\ No newline at end of file
-- 
Gitee


From 3f95f2a077dcb04ae8b0b7572fe15fe9028e96b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:48:51 +0000
Subject: [PATCH 06/13] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=20?=
 =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE./=E8=A2=81=E8=B4=B5=E6=A3=AE/?=
 =?UTF-8?q?=E7=AC=94=E8=AE=B0.txt?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../\347\254\224\350\256\260.txt"             | 111 ------------------
 1 file changed, 111 deletions(-)
 delete mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
deleted file mode 100644
index d318cf7..0000000
--- "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
+++ /dev/null
@@ -1,111 +0,0 @@
-**SQL中常用运算符**
-
-```sql
-=：等于，比较是否相等及赋值
-!=：比较不等于
->：比较大于
-<：比较小于
->=：比较大于等于
-<=：比较小于等于
-IS NULL：比较为空
-IS NOT NULL：比较不为空
-in：比较是否在其中
-like：模糊查询
-BETWEEN...AND...：比较是否在两者之间 50-100   BETWEEN 50 AND 100
-and：逻辑与（两个条件同时成立表达式成立）
-or：逻辑或（两个条件有一个成立表达式成立） 
-not：逻辑非（条件成立，表达式则不成立；条件不成立，表达式则成立）
-```
-#### 模糊查询
-
-模糊查询使用like关键字和通配符结合来实现，通配符具体含义如下：
-
-```sql
-%：代表匹配0个字符、1个字符或多个字符。
-_：代表匹配有且只有1个字符。
-[]：代表匹配范围内
-[^]：代表匹配不在范围内
-```
-#### 聚合函数
-
-SQL SERVER中聚合函数主要有：
-
-```sql
-count:求数量
-max:求最大值
-min:求最小值
-sum:求和
-avg:求平均值
-```
-ROUND函数用法：
-
-```sql
-round(num,len,[type])
-其中:
-num表示需要处理的数字，len表示需要保留的长度，type处理类型(0是默认值代表四舍五入，非0代表直接截取)
-select ROUND(123.45454,3)  --123.45500
-select ROUND(123.45454,3,1) --123.45400
-
-CONVERT()与CAST()函数:
-
-```sql
---1.保留小数
-convert(decimal(13,2),12.45454)
-cast(12.45454 as decimal(13,2))
---2.强制转换类型
-```
-
-
-
-#### SQL中常用的时间函数
-
-```sql
-select DATEDIFF(day, '2019-08-20', getDate());    --获取指定时间单位的差值
-SELECT DATEADD(MINUTE,-5,GETDATE())               --加减时间,此处为获取五分钟前的时间,MINUTE 表示分钟，可为 YEAR,MONTH,DAY,HOUR
-select DATENAME(month, getDate());                --当前月份
-select DATENAME(WEEKDAY, getDate());              --当前星期几
-select DATEPART(month, getDate());                --当前月份
-select DAY(getDate());                            --返回当前日期天数
-select MONTH(getDate());                          --返回当前日期月数
-select YEAR(getDate());                           --返回当前日期年数
-
-SELECT CONVERT(VARCHAR(22),GETDATE(),20)          --2020-01-09 14:46:46
-SELECT CONVERT(VARCHAR(24),GETDATE(),21)          --2020-01-09 14:46:55.91
-SELECT CONVERT(VARCHAR(22),GETDATE(),23)		  --2020-01-09
-SELECT CONVERT(VARCHAR(22),GETDATE(),24)          --15:04:07
-Select CONVERT(varchar(20),GETDATE(),14)          --15:05:49:330
-```
-
-**时间格式控制字符串：**
-
-| 名称         | 日期单位    | 缩写      |
-| ------------ | ----------- | --------- |
-| 年           | year        | yyyy 或yy |
-| 季度         | quarter     | qq,q      |
-| 月           | month       | mm,m      |
-| 一年中第几天 | dayofyear   | dy,y      |
-| 日           | day         | dd,d      |
-| 一年中第几周 | week        | wk,ww     |
-| 星期         | weekday     | dw        |
-| 小时         | Hour        | hh        |
-| 分钟         | minute      | mi,n      |
-| 秒           | second      | ss,s      |
-| 毫秒         | millisecond | ms        |
-
-SQL语句执行顺序:
-
-```sql
-(7)     SELECT 
-(8)     DISTINCT <select_list>
-(1)     FROM <left_table>
-(3)     <join_type> JOIN <right_table>
-(2)     ON <join_condition>
-(4)     WHERE <where_condition>
-(5)     GROUP BY <group_by_list>
-(6)     HAVING <having_condition>
-(9)     ORDER BY <order_by_condition>
-(10)    LIMIT <limit_number>
-```
-
-
-
-- 
Gitee


From e912d023a7af69b0e2a0c168bc38a50cf02f42d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:49:02 +0000
Subject: [PATCH 07/13] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=20?=
 =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256./.keep" | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 delete mode 100644 "\350\242\201\350\264\265\346\243\256./.keep"

diff --git "a/\350\242\201\350\264\265\346\243\256./.keep" "b/\350\242\201\350\264\265\346\243\256./.keep"
deleted file mode 100644
index e69de29..0000000
-- 
Gitee


From a261950a1f80741b36548a6bdcb133e541725dd3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:49:12 +0000
Subject: [PATCH 08/13] =?UTF-8?q?=E6=96=B0=E5=BB=BA=20=E8=A2=81=E8=B4=B5?=
 =?UTF-8?q?=E6=A3=AE.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256./.keep" | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 "\350\242\201\350\264\265\346\243\256./.keep"

diff --git "a/\350\242\201\350\264\265\346\243\256./.keep" "b/\350\242\201\350\264\265\346\243\256./.keep"
new file mode 100644
index 0000000..e69de29
-- 
Gitee


From 4864bd67301692890d84e021002b04b523b90444 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:49:25 +0000
Subject: [PATCH 09/13] =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 袁贵森 <3032059138@qq.com>
---
 .../SQLQuery1.sql"                            | 299 ++++++++++++++++++
 .../\347\254\224\350\256\260.txt"             | 111 +++++++
 2 files changed, 410 insertions(+)
 create mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
 create mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
new file mode 100644
index 0000000..0231695
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
@@ -0,0 +1,299 @@
+if exists(select * from sys.databases where name='DBTEST')
+drop database DBTEST;
+go
+
+create database DBTEST;
+go
+
+use DBTEST;
+go
+
+--�������ű�
+create table Department 
+(
+	--�������ű��;int������������;primary key��������;identity(1,1)������1��ʼ����Ϊ1������;
+	DepartmentId int primary key identity(1,1),
+	--������������;nvarchar(50)��������50���ַ���;not null��������Ϊ��;
+	DepartmentName nvarchar(50) not null,
+	--��������������text�������ı�;
+	DepartmentRemark text
+);
+go
+
+--����ְ������rankΪϵͳ�ؼ��֣��˴�ʹ��[]�����Զ������֣�����ϵͳ�ؼ���
+create table [Rank]
+(
+	RankId int primary key identity(1,1),
+	RankName nvarchar(50) not null,
+	RankRemark text
+);
+go
+
+--����Ա����Ϣ��
+create table People
+(
+	PeopleId int primary key identity(1,1),
+	--references�����������,���ֶα�������������������Լ��
+	DepartmentId int references Department(DepartmentId)  not null,
+	RankId int references [Rank](RankId) not null,
+	PeopleName nvarchar(50) not null,
+	--default�����ֶ�Ĭ��ֵ; check���Թ涨�ֶ�ֵ��Լ������;
+	PeopleSex nvarchar(1) default('��') check(PeopleSex='��' or PeopleSex='Ů') not null,
+	PeopleBirth datetime not null,
+	PeopleSalary decimal(12,2) check(PeopleSalary>= 1000 and PeopleSalary <= 100000) not null,
+	--unique����ΨһԼ����Ϊ�����ṩΨһ�Ա�֤;
+	PeoplePhone nvarchar(20) unique not null,
+	PeopleAddress nvarchar(100),
+	--datetime��smalldatetime�����Ա�ʾʱ�����ͣ�getdate()���ڻ�ȡϵͳ��ǰʱ��
+	PeopleAddTime smalldatetime default(getdate())
+);
+go
+
+
+
+------------------------------�������ݲ���------------------------------
+--���ű���������
+insert into Department values('������','��˾�������������IJ���');
+go
+
+--һ���Բ����������
+insert into Department(DepartmentName,DepartmentRemark)
+select '�г���','��ţ�IJ���' union
+select '��Ʒ��','�����ǿյIJ���' union
+select '�ܾ���','�����쵼�IJ���' ;
+go
+
+-------ְ������������
+insert into [Rank](RankName,RankRemark)
+values('����','�����������������')
+insert into [Rank](RankName,RankRemark)
+values('�м�','�߱������������������')
+insert into [Rank](RankName,RankRemark)
+values('�߼�','�߱����Դ���ȫ�����������');
+go
+
+---------��Ա������������
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,3,'����','��','1984-7-9',20000,'13554785452','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'������','Ů','1987-7-9',15000,'13256854578','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'����','��','1988-8-8',12000,'13985745871','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'�ŷ�','��','1990-8-8',8000,'13535987412','�˲�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'����','��','1989-4-8',9000,'13845789568','�˲�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'����','��','1995-4-8',9500,'13878562568','���',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'�Ƹ�','��','1989-4-20',8500,'13335457412','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,1,'����','Ů','1989-4-20',6500,'13437100050','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,2,'�ܲ�','��','1987-12-20',25000,'13889562354','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'����','��','1981-11-11',9000,'13385299632','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'��Τ','��','1978-1-13',8000,'13478545263','�Ϻ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'����','��','1998-12-12',7500,'13878523695','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,3,'���','��','1968-11-22',9000,'13698545841','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'���','��','1988-1-22',11000,'13558745874','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'��Ȩ','��','1990-2-21',12000,'13698745214','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'����','Ů','1995-2-21',13000,'13985478512','�Ϻ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'С��','Ů','1996-2-21',13500,'13778787874','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'���','��','1992-10-11',8000,'13987455214','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'³��','��','1984-9-10',5500,'13254785965','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'����','��','1987-5-19',8500,'13352197364','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'½ѷ','��','1996-5-19',7500,'13025457392','�Ͼ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'̫ʷ��','��','1983-6-1',7500,'13077778888','�Ϻ�',getdate())
+
+
+---��ѯ
+select * from Department
+select * from [Rank]
+select * from People 
+
+
+--1. ��ѯ������������
+
+--2. ָ���в�ѯ���������Ա���н���绰��
+select PeopleName as ���� ,Peoplesex as �Ա� from People;
+--3. ָ���в�ѯ,���Զ��������������������Ա���н���绰��
+--4. ��ѯ��˾Ա�����ڳ��У�����Ҫ�ظ����ݣ�
+
+--�����ظ��У�distinct
+select distinct peopleAddress from People; 
+--5. ���蹤���յ�10%����ѯԭʼ���ʺ͵�����Ĺ��ʣ���ʾ���������Ա���н����н�����н���������в�ѯ����
+select top 3 PeopleName ����, PeopleSalary ��н, PeopleSalary*1.1 ��н����н from People;
+
+--top ordey by
+
+
+select * from People 
+--����ָ���У��������Ա���н���绰����ѯ�Ա�ΪŮ��Ա����Ϣ,���Զ�����������
+--2. ��ѯ��н���ڵ���10000 ��Ա����Ϣ( ������ )
+--3. ��ѯ��н���ڵ���10000 ��ŮԱ����Ϣ(������)
+select * from People where PeopleSalary>=10000 and PeopleSex='Ů'
+--4. ��ʾ����������1980-1-1֮�󣬶�����н���ڵ���10000��ŮԱ����Ϣ��
+select * from People  where PeopleSalary>=10000 and PeopleSex='Ů' and PeopleBirth>'1995-1-1';  
+
+--5. ��ʾ����н���ڵ���15000 ��Ա��,������н���ڵ���8000��ŮԱ����Ϣ��
+select * from People where (PeopleSalary>=8000 and peoplesex='Ů') or PeopleSalary>=15000 
+--6. ��ѯ��н��10000-20000 ֮��Ա����Ϣ( ������ )
+select * from People where PeopleSalary between 10000 and 20000
+--7. ��ѯ����ַ�ڱ��������Ϻ���Ա����Ϣ
+--8. ��ѯ����Ա����Ϣ(���ݹ������򣬽�������): asc��Ĭ�ϣ�:����  desc:����
+select * from People order by PeopleSalary desc
+
+--9. ��ʾ���е�Ա����Ϣ���������ֵij��Ƚ��е�������
+--10. ��ѯ������ߵ�5���˵���Ϣ
+select top 5 * from People order by PeopleSalary desc
+--11. ��ѯ������ߵ�10%��Ա����Ϣ
+select top 10 percent *  from People order by PeopleSalary desc
+--12. ��ѯ����ַû����д��Ա����Ϣ
+--Ϊ�ղ�����=��is null, is not null
+select * from People where PeopleAddress is null;
+
+--13. ��ѯ����ַ�Ѿ���д��Ա����Ϣ
+--14. ��ѯ���е�80��Ա����Ϣ
+
+--15. ��ѯ������30-40 ֮�䣬���ҹ�����15000-30000 ֮���Ա����Ϣ
+--16. ��ѯ����з 6.22--7.22 ��Ա����Ϣ
+select * from people where 
+(MONTH(PeopleBirth)=6 and DAY(PeopleBirth)>=22) or  
+(MONTH(PeopleBirth)=7 and DAY(PeopleBirth)<=22)
+;
+--17. ��ѯ���ʱ����Ƹߵ���
+select * from people where PeopleSalary > 9000
+--18. ��ѯ����������ͬһ�����е���
+--19. ��ѯ����ФΪ�����Ա��Ϣ
+--20. ��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
+--case when end
+
+--��ѯ����з 6.22--7.22 ��Ա����Ϣ
+select * from People where
+(MONTH(PeopleBirth) = 6  and DAY(PeopleBirth) >=22) or
+(MONTH(PeopleBirth) = 7  and DAY(PeopleBirth) <=22)
+
+--1. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ���������Լ�Ա������ϸ����
+select p.*,d.DepartmentName �������� from People p
+inner join Department d on p.DepartmentId=d.DepartmentId
+where p.PeopleAddress='�人'
+
+
+--2. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ�������ƣ�ְ�������Լ�Ա������ϸ����
+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='�人'
+
+--3. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʡ�
+select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
+inner join Department d on d.DepartmentId=p.DepartmentId
+group by d.DepartmentId
+
+--4. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʣ�ƽ��������10000 ���µIJ�����ͳ�ƣ�
+--���Ҹ���ƽ�����ʽ������С�
+select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
+inner join Department d on d.DepartmentId=p.DepartmentId
+group by d.DepartmentId
+having convert(decimal(15,2),avg(PeopleSalary))>=10000
+order by ƽ������ desc
+
+--5. ���ݲ������ƣ�Ȼ�����ְλ���ƣ�����ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹���
+select [Rank].RankName ְλ����,count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,
+min(PeopleSalary) ��͹��� from Department
+inner join People on People.DepartmentId=Department.DepartmentId
+inner join [Rank] on People.RankId=[Rank].RankId
+group by [Rank].RankName
+
+--��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
+select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
+case 
+when  year(PeopleBirth) % 12 = 1 then '��'
+when  year(PeopleBirth) % 12 = 2 then 'ţ'
+when  year(PeopleBirth) % 12 = 3 then '��'
+when  year(PeopleBirth) % 12 = 4 then '��'
+when  year(PeopleBirth) % 12 = 5 then '��'
+when  year(PeopleBirth) % 12 = 6 then '��'
+when  year(PeopleBirth) % 12 = 7 then '��'
+when  year(PeopleBirth) % 12 = 8 then '��'
+when  year(PeopleBirth) % 12 = 9 then '��'
+when  year(PeopleBirth) % 12 = 10 then '��'
+when  year(PeopleBirth) % 12 = 11 then '��'
+when  year(PeopleBirth) % 12 = 0 then '��'
+else ''
+end "��Ф"
+from People 
+
+select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
+case
+    when year(PeopleBirth) % 12 = 4 then '��'
+    when year(PeopleBirth) % 12 = 5 then 'ţ'
+    when year(PeopleBirth) % 12 = 6 then '��'
+    when year(PeopleBirth) % 12 = 7 then '��'
+    when year(PeopleBirth) % 12 = 8 then '��'
+    when year(PeopleBirth) % 12 = 9 then '��'
+    when year(PeopleBirth) % 12 = 10 then '��'
+    when year(PeopleBirth) % 12 = 11 then '��'
+    when year(PeopleBirth) % 12 = 0 then '��'
+    when year(PeopleBirth) % 12 = 1 then '��'
+    when year(PeopleBirth) % 12 = 2 then '��'
+    when year(PeopleBirth) % 12 = 3 then '��'
+    ELSE ''
+end ��Ф
+from People
\ No newline at end of file
diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
new file mode 100644
index 0000000..d318cf7
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
@@ -0,0 +1,111 @@
+**SQL中常用运算符**
+
+```sql
+=：等于，比较是否相等及赋值
+!=：比较不等于
+>：比较大于
+<：比较小于
+>=：比较大于等于
+<=：比较小于等于
+IS NULL：比较为空
+IS NOT NULL：比较不为空
+in：比较是否在其中
+like：模糊查询
+BETWEEN...AND...：比较是否在两者之间 50-100   BETWEEN 50 AND 100
+and：逻辑与（两个条件同时成立表达式成立）
+or：逻辑或（两个条件有一个成立表达式成立） 
+not：逻辑非（条件成立，表达式则不成立；条件不成立，表达式则成立）
+```
+#### 模糊查询
+
+模糊查询使用like关键字和通配符结合来实现，通配符具体含义如下：
+
+```sql
+%：代表匹配0个字符、1个字符或多个字符。
+_：代表匹配有且只有1个字符。
+[]：代表匹配范围内
+[^]：代表匹配不在范围内
+```
+#### 聚合函数
+
+SQL SERVER中聚合函数主要有：
+
+```sql
+count:求数量
+max:求最大值
+min:求最小值
+sum:求和
+avg:求平均值
+```
+ROUND函数用法：
+
+```sql
+round(num,len,[type])
+其中:
+num表示需要处理的数字，len表示需要保留的长度，type处理类型(0是默认值代表四舍五入，非0代表直接截取)
+select ROUND(123.45454,3)  --123.45500
+select ROUND(123.45454,3,1) --123.45400
+
+CONVERT()与CAST()函数:
+
+```sql
+--1.保留小数
+convert(decimal(13,2),12.45454)
+cast(12.45454 as decimal(13,2))
+--2.强制转换类型
+```
+
+
+
+#### SQL中常用的时间函数
+
+```sql
+select DATEDIFF(day, '2019-08-20', getDate());    --获取指定时间单位的差值
+SELECT DATEADD(MINUTE,-5,GETDATE())               --加减时间,此处为获取五分钟前的时间,MINUTE 表示分钟，可为 YEAR,MONTH,DAY,HOUR
+select DATENAME(month, getDate());                --当前月份
+select DATENAME(WEEKDAY, getDate());              --当前星期几
+select DATEPART(month, getDate());                --当前月份
+select DAY(getDate());                            --返回当前日期天数
+select MONTH(getDate());                          --返回当前日期月数
+select YEAR(getDate());                           --返回当前日期年数
+
+SELECT CONVERT(VARCHAR(22),GETDATE(),20)          --2020-01-09 14:46:46
+SELECT CONVERT(VARCHAR(24),GETDATE(),21)          --2020-01-09 14:46:55.91
+SELECT CONVERT(VARCHAR(22),GETDATE(),23)		  --2020-01-09
+SELECT CONVERT(VARCHAR(22),GETDATE(),24)          --15:04:07
+Select CONVERT(varchar(20),GETDATE(),14)          --15:05:49:330
+```
+
+**时间格式控制字符串：**
+
+| 名称         | 日期单位    | 缩写      |
+| ------------ | ----------- | --------- |
+| 年           | year        | yyyy 或yy |
+| 季度         | quarter     | qq,q      |
+| 月           | month       | mm,m      |
+| 一年中第几天 | dayofyear   | dy,y      |
+| 日           | day         | dd,d      |
+| 一年中第几周 | week        | wk,ww     |
+| 星期         | weekday     | dw        |
+| 小时         | Hour        | hh        |
+| 分钟         | minute      | mi,n      |
+| 秒           | second      | ss,s      |
+| 毫秒         | millisecond | ms        |
+
+SQL语句执行顺序:
+
+```sql
+(7)     SELECT 
+(8)     DISTINCT <select_list>
+(1)     FROM <left_table>
+(3)     <join_type> JOIN <right_table>
+(2)     ON <join_condition>
+(4)     WHERE <where_condition>
+(5)     GROUP BY <group_by_list>
+(6)     HAVING <having_condition>
+(9)     ORDER BY <order_by_condition>
+(10)    LIMIT <limit_number>
+```
+
+
+
-- 
Gitee


From 95f947e71d5fd2179c91858b47ee5d609d6eee3d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:49:49 +0000
Subject: [PATCH 10/13] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=20?=
 =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256./.keep" |   0
 .../SQLQuery1.sql"                            | 299 ------------------
 .../\347\254\224\350\256\260.txt"             | 111 -------
 3 files changed, 410 deletions(-)
 delete mode 100644 "\350\242\201\350\264\265\346\243\256./.keep"
 delete mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
 delete mode 100644 "\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256./.keep" "b/\350\242\201\350\264\265\346\243\256./.keep"
deleted file mode 100644
index e69de29..0000000
diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
deleted file mode 100644
index 0231695..0000000
--- "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
+++ /dev/null
@@ -1,299 +0,0 @@
-if exists(select * from sys.databases where name='DBTEST')
-drop database DBTEST;
-go
-
-create database DBTEST;
-go
-
-use DBTEST;
-go
-
---�������ű�
-create table Department 
-(
-	--�������ű��;int������������;primary key��������;identity(1,1)������1��ʼ����Ϊ1������;
-	DepartmentId int primary key identity(1,1),
-	--������������;nvarchar(50)��������50���ַ���;not null��������Ϊ��;
-	DepartmentName nvarchar(50) not null,
-	--��������������text�������ı�;
-	DepartmentRemark text
-);
-go
-
---����ְ������rankΪϵͳ�ؼ��֣��˴�ʹ��[]�����Զ������֣�����ϵͳ�ؼ���
-create table [Rank]
-(
-	RankId int primary key identity(1,1),
-	RankName nvarchar(50) not null,
-	RankRemark text
-);
-go
-
---����Ա����Ϣ��
-create table People
-(
-	PeopleId int primary key identity(1,1),
-	--references�����������,���ֶα�������������������Լ��
-	DepartmentId int references Department(DepartmentId)  not null,
-	RankId int references [Rank](RankId) not null,
-	PeopleName nvarchar(50) not null,
-	--default�����ֶ�Ĭ��ֵ; check���Թ涨�ֶ�ֵ��Լ������;
-	PeopleSex nvarchar(1) default('��') check(PeopleSex='��' or PeopleSex='Ů') not null,
-	PeopleBirth datetime not null,
-	PeopleSalary decimal(12,2) check(PeopleSalary>= 1000 and PeopleSalary <= 100000) not null,
-	--unique����ΨһԼ����Ϊ�����ṩΨһ�Ա�֤;
-	PeoplePhone nvarchar(20) unique not null,
-	PeopleAddress nvarchar(100),
-	--datetime��smalldatetime�����Ա�ʾʱ�����ͣ�getdate()���ڻ�ȡϵͳ��ǰʱ��
-	PeopleAddTime smalldatetime default(getdate())
-);
-go
-
-
-
-------------------------------�������ݲ���------------------------------
---���ű���������
-insert into Department values('������','��˾�������������IJ���');
-go
-
---һ���Բ����������
-insert into Department(DepartmentName,DepartmentRemark)
-select '�г���','��ţ�IJ���' union
-select '��Ʒ��','�����ǿյIJ���' union
-select '�ܾ���','�����쵼�IJ���' ;
-go
-
--------ְ������������
-insert into [Rank](RankName,RankRemark)
-values('����','�����������������')
-insert into [Rank](RankName,RankRemark)
-values('�м�','�߱������������������')
-insert into [Rank](RankName,RankRemark)
-values('�߼�','�߱����Դ���ȫ�����������');
-go
-
----------��Ա������������
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,3,'����','��','1984-7-9',20000,'13554785452','�ɶ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,2,'������','Ů','1987-7-9',15000,'13256854578','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,1,'����','��','1988-8-8',12000,'13985745871','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,1,'�ŷ�','��','1990-8-8',8000,'13535987412','�˲�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,3,'����','��','1989-4-8',9000,'13845789568','�˲�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,3,'����','��','1995-4-8',9500,'13878562568','���',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,2,'�Ƹ�','��','1989-4-20',8500,'13335457412','�人',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,1,'����','Ů','1989-4-20',6500,'13437100050','�人',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,2,'�ܲ�','��','1987-12-20',25000,'13889562354','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,3,'����','��','1981-11-11',9000,'13385299632','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,1,'��Τ','��','1978-1-13',8000,'13478545263','�Ϻ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,1,'����','��','1998-12-12',7500,'13878523695','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,3,'���','��','1968-11-22',9000,'13698545841','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,3,'���','��','1988-1-22',11000,'13558745874','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,2,'��Ȩ','��','1990-2-21',12000,'13698745214','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,2,'����','Ů','1995-2-21',13000,'13985478512','�Ϻ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,1,'С��','Ů','1996-2-21',13500,'13778787874','����',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,2,'���','��','1992-10-11',8000,'13987455214','�人',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(2,3,'³��','��','1984-9-10',5500,'13254785965','�ɶ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(3,3,'����','��','1987-5-19',8500,'13352197364','�ɶ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,1,'½ѷ','��','1996-5-19',7500,'13025457392','�Ͼ�',getdate())
-
-insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
-PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
-values(1,2,'̫ʷ��','��','1983-6-1',7500,'13077778888','�Ϻ�',getdate())
-
-
----��ѯ
-select * from Department
-select * from [Rank]
-select * from People 
-
-
---1. ��ѯ������������
-
---2. ָ���в�ѯ���������Ա���н���绰��
-select PeopleName as ���� ,Peoplesex as �Ա� from People;
---3. ָ���в�ѯ,���Զ��������������������Ա���н���绰��
---4. ��ѯ��˾Ա�����ڳ��У�����Ҫ�ظ����ݣ�
-
---�����ظ��У�distinct
-select distinct peopleAddress from People; 
---5. ���蹤���յ�10%����ѯԭʼ���ʺ͵�����Ĺ��ʣ���ʾ���������Ա���н����н�����н���������в�ѯ����
-select top 3 PeopleName ����, PeopleSalary ��н, PeopleSalary*1.1 ��н����н from People;
-
---top ordey by
-
-
-select * from People 
---����ָ���У��������Ա���н���绰����ѯ�Ա�ΪŮ��Ա����Ϣ,���Զ�����������
---2. ��ѯ��н���ڵ���10000 ��Ա����Ϣ( ������ )
---3. ��ѯ��н���ڵ���10000 ��ŮԱ����Ϣ(������)
-select * from People where PeopleSalary>=10000 and PeopleSex='Ů'
---4. ��ʾ����������1980-1-1֮�󣬶�����н���ڵ���10000��ŮԱ����Ϣ��
-select * from People  where PeopleSalary>=10000 and PeopleSex='Ů' and PeopleBirth>'1995-1-1';  
-
---5. ��ʾ����н���ڵ���15000 ��Ա��,������н���ڵ���8000��ŮԱ����Ϣ��
-select * from People where (PeopleSalary>=8000 and peoplesex='Ů') or PeopleSalary>=15000 
---6. ��ѯ��н��10000-20000 ֮��Ա����Ϣ( ������ )
-select * from People where PeopleSalary between 10000 and 20000
---7. ��ѯ����ַ�ڱ��������Ϻ���Ա����Ϣ
---8. ��ѯ����Ա����Ϣ(���ݹ������򣬽�������): asc��Ĭ�ϣ�:����  desc:����
-select * from People order by PeopleSalary desc
-
---9. ��ʾ���е�Ա����Ϣ���������ֵij��Ƚ��е�������
---10. ��ѯ������ߵ�5���˵���Ϣ
-select top 5 * from People order by PeopleSalary desc
---11. ��ѯ������ߵ�10%��Ա����Ϣ
-select top 10 percent *  from People order by PeopleSalary desc
---12. ��ѯ����ַû����д��Ա����Ϣ
---Ϊ�ղ�����=��is null, is not null
-select * from People where PeopleAddress is null;
-
---13. ��ѯ����ַ�Ѿ���д��Ա����Ϣ
---14. ��ѯ���е�80��Ա����Ϣ
-
---15. ��ѯ������30-40 ֮�䣬���ҹ�����15000-30000 ֮���Ա����Ϣ
---16. ��ѯ����з 6.22--7.22 ��Ա����Ϣ
-select * from people where 
-(MONTH(PeopleBirth)=6 and DAY(PeopleBirth)>=22) or  
-(MONTH(PeopleBirth)=7 and DAY(PeopleBirth)<=22)
-;
---17. ��ѯ���ʱ����Ƹߵ���
-select * from people where PeopleSalary > 9000
---18. ��ѯ����������ͬһ�����е���
---19. ��ѯ����ФΪ�����Ա��Ϣ
---20. ��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
---case when end
-
---��ѯ����з 6.22--7.22 ��Ա����Ϣ
-select * from People where
-(MONTH(PeopleBirth) = 6  and DAY(PeopleBirth) >=22) or
-(MONTH(PeopleBirth) = 7  and DAY(PeopleBirth) <=22)
-
---1. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ���������Լ�Ա������ϸ����
-select p.*,d.DepartmentName �������� from People p
-inner join Department d on p.DepartmentId=d.DepartmentId
-where p.PeopleAddress='�人'
-
-
---2. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ�������ƣ�ְ�������Լ�Ա������ϸ����
-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='�人'
-
---3. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʡ�
-select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
-inner join Department d on d.DepartmentId=p.DepartmentId
-group by d.DepartmentId
-
---4. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʣ�ƽ��������10000 ���µIJ�����ͳ�ƣ�
---���Ҹ���ƽ�����ʽ������С�
-select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
-inner join Department d on d.DepartmentId=p.DepartmentId
-group by d.DepartmentId
-having convert(decimal(15,2),avg(PeopleSalary))>=10000
-order by ƽ������ desc
-
---5. ���ݲ������ƣ�Ȼ�����ְλ���ƣ�����ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹���
-select [Rank].RankName ְλ����,count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,
-min(PeopleSalary) ��͹��� from Department
-inner join People on People.DepartmentId=Department.DepartmentId
-inner join [Rank] on People.RankId=[Rank].RankId
-group by [Rank].RankName
-
---��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
-select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
-case 
-when  year(PeopleBirth) % 12 = 1 then '��'
-when  year(PeopleBirth) % 12 = 2 then 'ţ'
-when  year(PeopleBirth) % 12 = 3 then '��'
-when  year(PeopleBirth) % 12 = 4 then '��'
-when  year(PeopleBirth) % 12 = 5 then '��'
-when  year(PeopleBirth) % 12 = 6 then '��'
-when  year(PeopleBirth) % 12 = 7 then '��'
-when  year(PeopleBirth) % 12 = 8 then '��'
-when  year(PeopleBirth) % 12 = 9 then '��'
-when  year(PeopleBirth) % 12 = 10 then '��'
-when  year(PeopleBirth) % 12 = 11 then '��'
-when  year(PeopleBirth) % 12 = 0 then '��'
-else ''
-end "��Ф"
-from People 
-
-select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
-case
-    when year(PeopleBirth) % 12 = 4 then '��'
-    when year(PeopleBirth) % 12 = 5 then 'ţ'
-    when year(PeopleBirth) % 12 = 6 then '��'
-    when year(PeopleBirth) % 12 = 7 then '��'
-    when year(PeopleBirth) % 12 = 8 then '��'
-    when year(PeopleBirth) % 12 = 9 then '��'
-    when year(PeopleBirth) % 12 = 10 then '��'
-    when year(PeopleBirth) % 12 = 11 then '��'
-    when year(PeopleBirth) % 12 = 0 then '��'
-    when year(PeopleBirth) % 12 = 1 then '��'
-    when year(PeopleBirth) % 12 = 2 then '��'
-    when year(PeopleBirth) % 12 = 3 then '��'
-    ELSE ''
-end ��Ф
-from People
\ No newline at end of file
diff --git "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
deleted file mode 100644
index d318cf7..0000000
--- "a/\350\242\201\350\264\265\346\243\256./\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
+++ /dev/null
@@ -1,111 +0,0 @@
-**SQL中常用运算符**
-
-```sql
-=：等于，比较是否相等及赋值
-!=：比较不等于
->：比较大于
-<：比较小于
->=：比较大于等于
-<=：比较小于等于
-IS NULL：比较为空
-IS NOT NULL：比较不为空
-in：比较是否在其中
-like：模糊查询
-BETWEEN...AND...：比较是否在两者之间 50-100   BETWEEN 50 AND 100
-and：逻辑与（两个条件同时成立表达式成立）
-or：逻辑或（两个条件有一个成立表达式成立） 
-not：逻辑非（条件成立，表达式则不成立；条件不成立，表达式则成立）
-```
-#### 模糊查询
-
-模糊查询使用like关键字和通配符结合来实现，通配符具体含义如下：
-
-```sql
-%：代表匹配0个字符、1个字符或多个字符。
-_：代表匹配有且只有1个字符。
-[]：代表匹配范围内
-[^]：代表匹配不在范围内
-```
-#### 聚合函数
-
-SQL SERVER中聚合函数主要有：
-
-```sql
-count:求数量
-max:求最大值
-min:求最小值
-sum:求和
-avg:求平均值
-```
-ROUND函数用法：
-
-```sql
-round(num,len,[type])
-其中:
-num表示需要处理的数字，len表示需要保留的长度，type处理类型(0是默认值代表四舍五入，非0代表直接截取)
-select ROUND(123.45454,3)  --123.45500
-select ROUND(123.45454,3,1) --123.45400
-
-CONVERT()与CAST()函数:
-
-```sql
---1.保留小数
-convert(decimal(13,2),12.45454)
-cast(12.45454 as decimal(13,2))
---2.强制转换类型
-```
-
-
-
-#### SQL中常用的时间函数
-
-```sql
-select DATEDIFF(day, '2019-08-20', getDate());    --获取指定时间单位的差值
-SELECT DATEADD(MINUTE,-5,GETDATE())               --加减时间,此处为获取五分钟前的时间,MINUTE 表示分钟，可为 YEAR,MONTH,DAY,HOUR
-select DATENAME(month, getDate());                --当前月份
-select DATENAME(WEEKDAY, getDate());              --当前星期几
-select DATEPART(month, getDate());                --当前月份
-select DAY(getDate());                            --返回当前日期天数
-select MONTH(getDate());                          --返回当前日期月数
-select YEAR(getDate());                           --返回当前日期年数
-
-SELECT CONVERT(VARCHAR(22),GETDATE(),20)          --2020-01-09 14:46:46
-SELECT CONVERT(VARCHAR(24),GETDATE(),21)          --2020-01-09 14:46:55.91
-SELECT CONVERT(VARCHAR(22),GETDATE(),23)		  --2020-01-09
-SELECT CONVERT(VARCHAR(22),GETDATE(),24)          --15:04:07
-Select CONVERT(varchar(20),GETDATE(),14)          --15:05:49:330
-```
-
-**时间格式控制字符串：**
-
-| 名称         | 日期单位    | 缩写      |
-| ------------ | ----------- | --------- |
-| 年           | year        | yyyy 或yy |
-| 季度         | quarter     | qq,q      |
-| 月           | month       | mm,m      |
-| 一年中第几天 | dayofyear   | dy,y      |
-| 日           | day         | dd,d      |
-| 一年中第几周 | week        | wk,ww     |
-| 星期         | weekday     | dw        |
-| 小时         | Hour        | hh        |
-| 分钟         | minute      | mi,n      |
-| 秒           | second      | ss,s      |
-| 毫秒         | millisecond | ms        |
-
-SQL语句执行顺序:
-
-```sql
-(7)     SELECT 
-(8)     DISTINCT <select_list>
-(1)     FROM <left_table>
-(3)     <join_type> JOIN <right_table>
-(2)     ON <join_condition>
-(4)     WHERE <where_condition>
-(5)     GROUP BY <group_by_list>
-(6)     HAVING <having_condition>
-(9)     ORDER BY <order_by_condition>
-(10)    LIMIT <limit_number>
-```
-
-
-
-- 
Gitee


From 1ab370beb33b79e7b1b4e8a05bf2867f54694f15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:49:57 +0000
Subject: [PATCH 11/13] =?UTF-8?q?=E5=88=A0=E9=99=A4=E6=96=87=E4=BB=B6=20?=
 =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256/.keep"  |  0
 "\350\242\201\350\264\265\346\243\256/28.sql" | 52 -----------------
 .../\347\254\224\350\256\260.txt"             | 58 -------------------
 3 files changed, 110 deletions(-)
 delete mode 100644 "\350\242\201\350\264\265\346\243\256/.keep"
 delete mode 100644 "\350\242\201\350\264\265\346\243\256/28.sql"
 delete mode 100644 "\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256/.keep" "b/\350\242\201\350\264\265\346\243\256/.keep"
deleted file mode 100644
index e69de29..0000000
diff --git "a/\350\242\201\350\264\265\346\243\256/28.sql" "b/\350\242\201\350\264\265\346\243\256/28.sql"
deleted file mode 100644
index 9f2be17..0000000
--- "a/\350\242\201\350\264\265\346\243\256/28.sql"
+++ /dev/null
@@ -1,52 +0,0 @@
---判断数据库是否存在
-if exists (select * from sys.databases where name='DBTEXT')
-drop database DBTEXT;
---创建数据库
-create database DBTEXT
---使用数据库
-
-
---创建数据表
---primary key 主键
---identity 自增(标识符)
---default 默约束
---check 检查
-
---部门信息表
-create table sectionInfo(
-	 sectionID int primary key identity(2010,1),
-	sectionName varchar(10) not null
-);
-
-INSERT into sectionInfo (sectionName) VALUES ('张三','李四','全网','暗属性出','认为对方','违法的'),
---员工信息表
-create table userInfo(
-	userNo int identity(1000,1) primary key not null,
-	userName varchar(10)  not null check(len(userName)>4) unique,
-	userSex varchar(2) not null check(userSex='男' or userSex='女'),
-	userAge int not null check(userAge between 1 and 100),
-	userAddress varchar(50) default ('湖北'),
-	userSection  int
-); 
-Alter table sectionInfo add constraint FK_sectionInfo_ClassId foreign key(userSection) references asd(sectionID);
-INSERT into userInfo (userName,userSex,userAge,userAddress,userSection) VALUES
-('张三','男',19,'湖南',1),
-('张嘶','女',20,'福建',2),
-('张无','女',17,'广东',1),
-('张六','男',19,'湖北',2),
-('张气','男',17,'湖南',1)
---员工考勤表
-create table workInfo(
-	workId int identity(1,1) primary key not null,
-	userId int  not null,
-	workTime datetime not null,
-	workDescription varchar (40) not null check(workDescription='迟到' or workDescription='早退' or workDescription='旷工' or workDescription='病假' or workDescription='事假')
-);
-Alter table workInfo add constraint FK_workInfo_ClassId foreign key(userId) references sectionInfo(userNo);
-
-INSERT into workInfo (workTime,workDescription) VALUES
-('2021-09-05','早退'),
-('2022-08-06','迟到'),
-('2023-09-10','事假'),
-('2020-09-20','旷工'),
-('2021-10-05','病假')
\ No newline at end of file
diff --git "a/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
deleted file mode 100644
index 3631665..0000000
--- "a/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
+++ /dev/null
@@ -1,58 +0,0 @@
---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;
\ No newline at end of file
-- 
Gitee


From f797da6eed476dc7b4d581464f09772a4ca79f2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:50:08 +0000
Subject: [PATCH 12/13] =?UTF-8?q?=E6=96=B0=E5=BB=BA=20=E8=A2=81=E8=B4=B5?=
 =?UTF-8?q?=E6=A3=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 "\350\242\201\350\264\265\346\243\256/.keep" | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 "\350\242\201\350\264\265\346\243\256/.keep"

diff --git "a/\350\242\201\350\264\265\346\243\256/.keep" "b/\350\242\201\350\264\265\346\243\256/.keep"
new file mode 100644
index 0000000..e69de29
-- 
Gitee


From 49b9b3c0f102b67e1d99e7ff7f0947111862a5c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?= <3032059138@qq.com>
Date: Sun, 18 Sep 2022 14:50:22 +0000
Subject: [PATCH 13/13] =?UTF-8?q?=E8=A2=81=E8=B4=B5=E6=A3=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 袁贵森 <3032059138@qq.com>
---
 .../SQLQuery1.sql"                            | 299 ++++++++++++++++++
 .../\347\254\224\350\256\260.txt"             | 111 +++++++
 2 files changed, 410 insertions(+)
 create mode 100644 "\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
 create mode 100644 "\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"

diff --git "a/\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/SQLQuery1.sql" "b/\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
new file mode 100644
index 0000000..0231695
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/SQLQuery1.sql"
@@ -0,0 +1,299 @@
+if exists(select * from sys.databases where name='DBTEST')
+drop database DBTEST;
+go
+
+create database DBTEST;
+go
+
+use DBTEST;
+go
+
+--�������ű�
+create table Department 
+(
+	--�������ű��;int������������;primary key��������;identity(1,1)������1��ʼ����Ϊ1������;
+	DepartmentId int primary key identity(1,1),
+	--������������;nvarchar(50)��������50���ַ���;not null��������Ϊ��;
+	DepartmentName nvarchar(50) not null,
+	--��������������text�������ı�;
+	DepartmentRemark text
+);
+go
+
+--����ְ������rankΪϵͳ�ؼ��֣��˴�ʹ��[]�����Զ������֣�����ϵͳ�ؼ���
+create table [Rank]
+(
+	RankId int primary key identity(1,1),
+	RankName nvarchar(50) not null,
+	RankRemark text
+);
+go
+
+--����Ա����Ϣ��
+create table People
+(
+	PeopleId int primary key identity(1,1),
+	--references�����������,���ֶα�������������������Լ��
+	DepartmentId int references Department(DepartmentId)  not null,
+	RankId int references [Rank](RankId) not null,
+	PeopleName nvarchar(50) not null,
+	--default�����ֶ�Ĭ��ֵ; check���Թ涨�ֶ�ֵ��Լ������;
+	PeopleSex nvarchar(1) default('��') check(PeopleSex='��' or PeopleSex='Ů') not null,
+	PeopleBirth datetime not null,
+	PeopleSalary decimal(12,2) check(PeopleSalary>= 1000 and PeopleSalary <= 100000) not null,
+	--unique����ΨһԼ����Ϊ�����ṩΨһ�Ա�֤;
+	PeoplePhone nvarchar(20) unique not null,
+	PeopleAddress nvarchar(100),
+	--datetime��smalldatetime�����Ա�ʾʱ�����ͣ�getdate()���ڻ�ȡϵͳ��ǰʱ��
+	PeopleAddTime smalldatetime default(getdate())
+);
+go
+
+
+
+------------------------------�������ݲ���------------------------------
+--���ű���������
+insert into Department values('������','��˾�������������IJ���');
+go
+
+--һ���Բ����������
+insert into Department(DepartmentName,DepartmentRemark)
+select '�г���','��ţ�IJ���' union
+select '��Ʒ��','�����ǿյIJ���' union
+select '�ܾ���','�����쵼�IJ���' ;
+go
+
+-------ְ������������
+insert into [Rank](RankName,RankRemark)
+values('����','�����������������')
+insert into [Rank](RankName,RankRemark)
+values('�м�','�߱������������������')
+insert into [Rank](RankName,RankRemark)
+values('�߼�','�߱����Դ���ȫ�����������');
+go
+
+---------��Ա������������
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,3,'����','��','1984-7-9',20000,'13554785452','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'������','Ů','1987-7-9',15000,'13256854578','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'����','��','1988-8-8',12000,'13985745871','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'�ŷ�','��','1990-8-8',8000,'13535987412','�˲�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'����','��','1989-4-8',9000,'13845789568','�˲�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'����','��','1995-4-8',9500,'13878562568','���',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'�Ƹ�','��','1989-4-20',8500,'13335457412','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,1,'����','Ů','1989-4-20',6500,'13437100050','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,2,'�ܲ�','��','1987-12-20',25000,'13889562354','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'����','��','1981-11-11',9000,'13385299632','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'��Τ','��','1978-1-13',8000,'13478545263','�Ϻ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'����','��','1998-12-12',7500,'13878523695','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,3,'���','��','1968-11-22',9000,'13698545841','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'���','��','1988-1-22',11000,'13558745874','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'��Ȩ','��','1990-2-21',12000,'13698745214','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,2,'����','Ů','1995-2-21',13000,'13985478512','�Ϻ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,1,'С��','Ů','1996-2-21',13500,'13778787874','����',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'���','��','1992-10-11',8000,'13987455214','�人',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(2,3,'³��','��','1984-9-10',5500,'13254785965','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(3,3,'����','��','1987-5-19',8500,'13352197364','�ɶ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,1,'½ѷ','��','1996-5-19',7500,'13025457392','�Ͼ�',getdate())
+
+insert into People(DepartmentId,RankId,PeopleName,PeopleSex,PeopleBirth,
+PeopleSalary,PeoplePhone,PeopleAddress,PeopleAddTime)
+values(1,2,'̫ʷ��','��','1983-6-1',7500,'13077778888','�Ϻ�',getdate())
+
+
+---��ѯ
+select * from Department
+select * from [Rank]
+select * from People 
+
+
+--1. ��ѯ������������
+
+--2. ָ���в�ѯ���������Ա���н���绰��
+select PeopleName as ���� ,Peoplesex as �Ա� from People;
+--3. ָ���в�ѯ,���Զ��������������������Ա���н���绰��
+--4. ��ѯ��˾Ա�����ڳ��У�����Ҫ�ظ����ݣ�
+
+--�����ظ��У�distinct
+select distinct peopleAddress from People; 
+--5. ���蹤���յ�10%����ѯԭʼ���ʺ͵�����Ĺ��ʣ���ʾ���������Ա���н����н�����н���������в�ѯ����
+select top 3 PeopleName ����, PeopleSalary ��н, PeopleSalary*1.1 ��н����н from People;
+
+--top ordey by
+
+
+select * from People 
+--����ָ���У��������Ա���н���绰����ѯ�Ա�ΪŮ��Ա����Ϣ,���Զ�����������
+--2. ��ѯ��н���ڵ���10000 ��Ա����Ϣ( ������ )
+--3. ��ѯ��н���ڵ���10000 ��ŮԱ����Ϣ(������)
+select * from People where PeopleSalary>=10000 and PeopleSex='Ů'
+--4. ��ʾ����������1980-1-1֮�󣬶�����н���ڵ���10000��ŮԱ����Ϣ��
+select * from People  where PeopleSalary>=10000 and PeopleSex='Ů' and PeopleBirth>'1995-1-1';  
+
+--5. ��ʾ����н���ڵ���15000 ��Ա��,������н���ڵ���8000��ŮԱ����Ϣ��
+select * from People where (PeopleSalary>=8000 and peoplesex='Ů') or PeopleSalary>=15000 
+--6. ��ѯ��н��10000-20000 ֮��Ա����Ϣ( ������ )
+select * from People where PeopleSalary between 10000 and 20000
+--7. ��ѯ����ַ�ڱ��������Ϻ���Ա����Ϣ
+--8. ��ѯ����Ա����Ϣ(���ݹ������򣬽�������): asc��Ĭ�ϣ�:����  desc:����
+select * from People order by PeopleSalary desc
+
+--9. ��ʾ���е�Ա����Ϣ���������ֵij��Ƚ��е�������
+--10. ��ѯ������ߵ�5���˵���Ϣ
+select top 5 * from People order by PeopleSalary desc
+--11. ��ѯ������ߵ�10%��Ա����Ϣ
+select top 10 percent *  from People order by PeopleSalary desc
+--12. ��ѯ����ַû����д��Ա����Ϣ
+--Ϊ�ղ�����=��is null, is not null
+select * from People where PeopleAddress is null;
+
+--13. ��ѯ����ַ�Ѿ���д��Ա����Ϣ
+--14. ��ѯ���е�80��Ա����Ϣ
+
+--15. ��ѯ������30-40 ֮�䣬���ҹ�����15000-30000 ֮���Ա����Ϣ
+--16. ��ѯ����з 6.22--7.22 ��Ա����Ϣ
+select * from people where 
+(MONTH(PeopleBirth)=6 and DAY(PeopleBirth)>=22) or  
+(MONTH(PeopleBirth)=7 and DAY(PeopleBirth)<=22)
+;
+--17. ��ѯ���ʱ����Ƹߵ���
+select * from people where PeopleSalary > 9000
+--18. ��ѯ����������ͬһ�����е���
+--19. ��ѯ����ФΪ�����Ա��Ϣ
+--20. ��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
+--case when end
+
+--��ѯ����з 6.22--7.22 ��Ա����Ϣ
+select * from People where
+(MONTH(PeopleBirth) = 6  and DAY(PeopleBirth) >=22) or
+(MONTH(PeopleBirth) = 7  and DAY(PeopleBirth) <=22)
+
+--1. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ���������Լ�Ա������ϸ����
+select p.*,d.DepartmentName �������� from People p
+inner join Department d on p.DepartmentId=d.DepartmentId
+where p.PeopleAddress='�人'
+
+
+--2. ��ѯ���人�������е�Ա����Ϣ��Ҫ����ʾ�������ƣ�ְ�������Լ�Ա������ϸ����
+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='�人'
+
+--3. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʡ�
+select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
+inner join Department d on d.DepartmentId=p.DepartmentId
+group by d.DepartmentId
+
+--4. ���ݲ��ŷ���ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹��ʣ�ƽ��������10000 ���µIJ�����ͳ�ƣ�
+--���Ҹ���ƽ�����ʽ������С�
+select count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,min(PeopleSalary) ��͹��� from people p
+inner join Department d on d.DepartmentId=p.DepartmentId
+group by d.DepartmentId
+having convert(decimal(15,2),avg(PeopleSalary))>=10000
+order by ƽ������ desc
+
+--5. ���ݲ������ƣ�Ȼ�����ְλ���ƣ�����ͳ��Ա��������Ա�������ܺͣ�ƽ�����ʣ���߹��ʺ���͹���
+select [Rank].RankName ְλ����,count(*) Ա������,sum(PeopleSalary) Ա�������ܺ�,convert(decimal(15,2),avg(PeopleSalary)) ƽ������,max(PeopleSalary) ��߹���,
+min(PeopleSalary) ��͹��� from Department
+inner join People on People.DepartmentId=Department.DepartmentId
+inner join [Rank] on People.RankId=[Rank].RankId
+group by [Rank].RankName
+
+--��ѯ����Ա����Ϣ������һ����ʾ����(��,ţ,��,��,��,��,��,��,��,��,��,��)
+select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
+case 
+when  year(PeopleBirth) % 12 = 1 then '��'
+when  year(PeopleBirth) % 12 = 2 then 'ţ'
+when  year(PeopleBirth) % 12 = 3 then '��'
+when  year(PeopleBirth) % 12 = 4 then '��'
+when  year(PeopleBirth) % 12 = 5 then '��'
+when  year(PeopleBirth) % 12 = 6 then '��'
+when  year(PeopleBirth) % 12 = 7 then '��'
+when  year(PeopleBirth) % 12 = 8 then '��'
+when  year(PeopleBirth) % 12 = 9 then '��'
+when  year(PeopleBirth) % 12 = 10 then '��'
+when  year(PeopleBirth) % 12 = 11 then '��'
+when  year(PeopleBirth) % 12 = 0 then '��'
+else ''
+end "��Ф"
+from People 
+
+select PeopleName ����,PeopleSex �Ա�,PeopleSalary ����,PeoplePhone �绰,PEOPLEBIRTH ����,
+case
+    when year(PeopleBirth) % 12 = 4 then '��'
+    when year(PeopleBirth) % 12 = 5 then 'ţ'
+    when year(PeopleBirth) % 12 = 6 then '��'
+    when year(PeopleBirth) % 12 = 7 then '��'
+    when year(PeopleBirth) % 12 = 8 then '��'
+    when year(PeopleBirth) % 12 = 9 then '��'
+    when year(PeopleBirth) % 12 = 10 then '��'
+    when year(PeopleBirth) % 12 = 11 then '��'
+    when year(PeopleBirth) % 12 = 0 then '��'
+    when year(PeopleBirth) % 12 = 1 then '��'
+    when year(PeopleBirth) % 12 = 2 then '��'
+    when year(PeopleBirth) % 12 = 3 then '��'
+    ELSE ''
+end ��Ф
+from People
\ No newline at end of file
diff --git "a/\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt" "b/\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
new file mode 100644
index 0000000..d318cf7
--- /dev/null
+++ "b/\350\242\201\350\264\265\346\243\256/\350\242\201\350\264\265\346\243\256/\347\254\224\350\256\260.txt"
@@ -0,0 +1,111 @@
+**SQL中常用运算符**
+
+```sql
+=：等于，比较是否相等及赋值
+!=：比较不等于
+>：比较大于
+<：比较小于
+>=：比较大于等于
+<=：比较小于等于
+IS NULL：比较为空
+IS NOT NULL：比较不为空
+in：比较是否在其中
+like：模糊查询
+BETWEEN...AND...：比较是否在两者之间 50-100   BETWEEN 50 AND 100
+and：逻辑与（两个条件同时成立表达式成立）
+or：逻辑或（两个条件有一个成立表达式成立） 
+not：逻辑非（条件成立，表达式则不成立；条件不成立，表达式则成立）
+```
+#### 模糊查询
+
+模糊查询使用like关键字和通配符结合来实现，通配符具体含义如下：
+
+```sql
+%：代表匹配0个字符、1个字符或多个字符。
+_：代表匹配有且只有1个字符。
+[]：代表匹配范围内
+[^]：代表匹配不在范围内
+```
+#### 聚合函数
+
+SQL SERVER中聚合函数主要有：
+
+```sql
+count:求数量
+max:求最大值
+min:求最小值
+sum:求和
+avg:求平均值
+```
+ROUND函数用法：
+
+```sql
+round(num,len,[type])
+其中:
+num表示需要处理的数字，len表示需要保留的长度，type处理类型(0是默认值代表四舍五入，非0代表直接截取)
+select ROUND(123.45454,3)  --123.45500
+select ROUND(123.45454,3,1) --123.45400
+
+CONVERT()与CAST()函数:
+
+```sql
+--1.保留小数
+convert(decimal(13,2),12.45454)
+cast(12.45454 as decimal(13,2))
+--2.强制转换类型
+```
+
+
+
+#### SQL中常用的时间函数
+
+```sql
+select DATEDIFF(day, '2019-08-20', getDate());    --获取指定时间单位的差值
+SELECT DATEADD(MINUTE,-5,GETDATE())               --加减时间,此处为获取五分钟前的时间,MINUTE 表示分钟，可为 YEAR,MONTH,DAY,HOUR
+select DATENAME(month, getDate());                --当前月份
+select DATENAME(WEEKDAY, getDate());              --当前星期几
+select DATEPART(month, getDate());                --当前月份
+select DAY(getDate());                            --返回当前日期天数
+select MONTH(getDate());                          --返回当前日期月数
+select YEAR(getDate());                           --返回当前日期年数
+
+SELECT CONVERT(VARCHAR(22),GETDATE(),20)          --2020-01-09 14:46:46
+SELECT CONVERT(VARCHAR(24),GETDATE(),21)          --2020-01-09 14:46:55.91
+SELECT CONVERT(VARCHAR(22),GETDATE(),23)		  --2020-01-09
+SELECT CONVERT(VARCHAR(22),GETDATE(),24)          --15:04:07
+Select CONVERT(varchar(20),GETDATE(),14)          --15:05:49:330
+```
+
+**时间格式控制字符串：**
+
+| 名称         | 日期单位    | 缩写      |
+| ------------ | ----------- | --------- |
+| 年           | year        | yyyy 或yy |
+| 季度         | quarter     | qq,q      |
+| 月           | month       | mm,m      |
+| 一年中第几天 | dayofyear   | dy,y      |
+| 日           | day         | dd,d      |
+| 一年中第几周 | week        | wk,ww     |
+| 星期         | weekday     | dw        |
+| 小时         | Hour        | hh        |
+| 分钟         | minute      | mi,n      |
+| 秒           | second      | ss,s      |
+| 毫秒         | millisecond | ms        |
+
+SQL语句执行顺序:
+
+```sql
+(7)     SELECT 
+(8)     DISTINCT <select_list>
+(1)     FROM <left_table>
+(3)     <join_type> JOIN <right_table>
+(2)     ON <join_condition>
+(4)     WHERE <where_condition>
+(5)     GROUP BY <group_by_list>
+(6)     HAVING <having_condition>
+(9)     ORDER BY <order_by_condition>
+(10)    LIMIT <limit_number>
+```
+
+
+
-- 
Gitee