From 91fe49bb30d73664c6d904f2e1366b7d5b087b78 Mon Sep 17 00:00:00 2001
From: xiao-a-qi <1307421235@qq.com>
Date: Fri, 16 Apr 2021 07:37:56 +0800
Subject: [PATCH] first commit

---
 .../SQLQuery2.sql"                            | 462 ++++++++++++++++++
 .../SQLQuery3.sql"                            |  41 ++
 .../SQLQuery4.sql"                            |  53 ++
 .../SQLQuery5.sql"                            |  39 ++
 .../demo1.java"                               |  35 ++
 .../demo2.java"                               |  16 +
 .../demo3.java"                               |  40 ++
 .../demo4.java"                               |  18 +
 8 files changed, 704 insertions(+)
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery2.sql"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery3.sql"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery4.sql"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery5.sql"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo1.java"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo2.java"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo3.java"
 create mode 100644 "\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo4.java"

diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery2.sql" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery2.sql"
new file mode 100644
index 0000000..fd81d59
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery2.sql"
@@ -0,0 +1,462 @@
+create database ClassicDb
+
+GO
+
+
+
+use ClassicDb
+
+GO
+
+
+
+create table StudentInfo
+
+(
+
+    Id int PRIMARY key not null IDENTITY,
+
+    StudentCode nvarchar(80),
+
+    StudentName nvarchar(80),
+
+    Birthday date not null,
+
+    Sex nvarchar(2),
+
+    ClassId int not null
+
+)
+
+
+
+GO
+
+
+
+-- select * from StudentInfo
+
+
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('01' , '赵雷' , '1990-01-01' , 'm',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('02' , '钱电' , '1990-12-21' , 'm',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('03' , '孙风' , '1990-12-20' , 'm',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('04' , '李云' , '1990-12-06' , 'm',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('05' , '周梅' , '1991-12-01' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('06' , '吴兰' , '1992-01-01' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('07' , '郑竹' , '1989-01-01' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('09' , '张三' , '2017-12-20' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('10' , '李四' , '2017-12-25' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('11' , '李四' , '2012-06-06' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('12' , '赵六' , '2013-06-13' , 'f',1)
+
+insert into StudentInfo (StudentCode,StudentName,Birthday,Sex,ClassId) values('13' , '孙七' , '2014-06-01' , 'f',1)
+
+
+
+
+
+GO
+
+
+
+
+
+CREATE TABLE Teachers
+
+(
+
+    Id int PRIMARY key not null IDENTITY,
+
+    TeacherName nvarchar(80)
+
+)
+
+
+
+go
+
+-- select * from Teachers
+
+
+
+insert into Teachers (TeacherName) values('张三')
+
+insert into Teachers (TeacherName) values('李四')
+
+insert into Teachers (TeacherName) values('王五')
+
+
+
+GO
+
+
+
+create table CourseInfo
+
+(
+
+    Id int PRIMARY key not null IDENTITY,
+
+    CourseName NVARCHAR(80) not null,
+
+    TeacherId int not null
+
+)
+
+
+
+go
+
+-- select * from CourseInfo
+
+
+
+insert into CourseInfo (CourseName,TeacherId) values( '语文' , 2)
+
+insert into CourseInfo (CourseName,TeacherId) values( '数学' , 1)
+
+insert into CourseInfo (CourseName,TeacherId) values( '英语' , 3)
+
+
+
+GO
+
+
+
+create table StudentCourseScore
+
+(
+
+    Id int PRIMARY key not null IDENTITY,
+
+    StudentId int not null,
+
+    CourseId int not null,
+
+    Score int not null
+
+)
+
+go
+
+-- select * from StudentCourseScore
+
+
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='01') , 1 , 80)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='01') , 2 , 90)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='01') , 3 , 99)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='02') , 1 , 70)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='02') , 2 , 60)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='02') , 3 , 80)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='03') , 1 , 80)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='03') , 2 , 80)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='03') , 3 , 80)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='04') , 1 , 50)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='04') , 2 , 30)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='04') , 3 , 20)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='05') , 1 , 76)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='05') , 2 , 87)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='06') , 1 , 31)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='06') , 3 , 34)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='07') , 2 , 89)
+
+insert into StudentCourseScore (StudentId,CourseId,Score) values((select Id from StudentInfo where StudentCode='07') , 3 , 98)
+
+
+
+go
+-- 练习题目：
+
+select *from CourseInfo
+select *from StudentCourseScore
+select *from StudentInfo
+select *from Teachers
+
+
+-- 1.查询"数学 "课程比" 语文 "课程成绩高的学生的信息及课程分数
+
+select * from 
+	(select * from StudentCourseScore where courseId = 1) as A
+		inner join StudentInfo s on s.Id = A.Id,
+	(select * from StudentCourseScore where CourseId = 2) as B
+			where A.Score > B.Score and A.StudentId = B.StudentId
+
+
+-- 1.1 查询同时存在" 数学 "课程和" 语文 "课程的情况
+
+select StudentId from StudentCourseScore
+	where CourseId = 1 or CourseId = 2
+	 group by StudentId
+		HAVING COUNT(distinct CourseId) = 2
+		
+
+-- 1.2 查询存在" 数学 "课程但可能不存在" 语文 "课程的情况(不存在时显示为 null )
+
+select * from
+	(select * from StudentCourseScore where CourseId = 2) A
+	left join (select * from StudentCourseScore where CourseId = 1) B on A.StudentId = B.StudentId
+
+-- 1.3 查询不存在" 数学 "课程但存在" 语文 "课程的情况
+
+select * from 
+	(select * from StudentCourseScore where CourseId = 1) A
+	left join (select * from StudentCourseScore where CourseId = 2) B on A.StudentId = B.StudentId
+		where B.CourseId is null
+
+-- 2.查询平均成绩大于等于 60 分的同学的学生编号和学生姓名和平均成绩
+
+select Studentcode 学生编号,StudentName 学生姓名,AVG(Score) 平均成绩 from StudentCourseScore
+	inner join StudentInfo on StudentCourseScore.StudentId = StudentInfo.StudentCode
+		group by Studentcode,StudentName
+			HAVING AVG(Score) >= 60
+
+-- 3.查询在 成绩 表存在成绩的学生信息
+
+select * from StudentCourseScore 
+	left join StudentInfo on StudentCourseScore.StudentId = StudentInfo.StudentCode
+
+-- 4.查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩(没成绩的显示为 null )
+
+select StudentCode ,StudentName ,COUNT(CourseId) ,SUM(Score) from StudentCourseScore scs
+	right join StudentInfo si on scs.StudentId = si.StudentCode
+		group by StudentCode,StudentName
+
+-- 4.1 查有成绩的学生信息
+
+select * from StudentCourseScore scs
+	inner join StudentInfo si on scs.StudentId = si.StudentCode
+
+-- 5.查询「李」姓老师的数量
+
+select COUNT(TeacherName) from Teachers
+	where TeacherName like '李%'
+
+-- 6.查询学过 「张三」老师授课 的 同学的信息
+
+select * from StudentCourseScore A
+	inner join CourseInfo B on A.CourseId = B.Id
+	inner join StudentInfo C on A.StudentId = C.StudentCode
+	inner join Teachers D on B.TeacherId = D.Id
+		where TeacherName = '张三'
+
+-- 7.查询没有学全所有课程的同学的信息
+select * from CourseInfo
+select * from StudentCourseScore
+select * from StudentInfo
+select * from Teachers
+
+select StudentCode ,StudentName from StudentCourseScore A
+	inner join StudentInfo B on A.StudentId = B.StudentCode 
+		group by StudentCode,StudentName
+			HAVING COUNT(CourseId) < (select COUNT(CourseName) from CourseInfo)
+
+-- 8.查询至少有一门课与学号为" 01 "的同学所学相同的同学的信息
+
+select StudentCode ,StudentName from StudentCourseScore A
+	inner join StudentInfo B on A.StudentId = B.StudentCode
+		group by  StudentCode ,StudentName
+			having count(CourseId) > 0
+
+-- 9.查询和" 01 "号的同学学习的课程 完全相同的其他同学的信息
+
+select StudentCode ,StudentName from StudentCourseScore A
+	inner join StudentInfo B on A.StudentId = B.StudentCode
+		group by  StudentCode ,StudentName
+			having count(CourseId)=(select COUNT(CourseName) from CourseInfo)
+
+-- 10.查询没学过"张三"老师讲授的任一门课程的学生姓名
+
+select distinct studentName from StudentCourseScore A
+	inner join CourseInfo B on A.CourseId = B.Id
+	inner join StudentInfo C on A.StudentId = C.StudentCode
+	inner join Teachers D on B.TeacherId = D.Id
+		where TeacherName != '张三'
+
+
+-- 11.查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩
+
+
+
+-- 12.检索" 数学 "课程分数小于 60，按分数降序排列的学生信息
+
+
+
+-- 13.按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩
+
+
+
+-- 14.查询各科成绩最高分、最低分和平均分：
+
+
+
+-- 15.以如下形式显示：课程 ID，课程 name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率
+
+/*
+
+	及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90
+
+
+
+	要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列
+
+
+
+	按各科成绩进行排序，并显示排名， Score 重复时保留名次空缺
+
+*/	
+
+	
+
+-- 15.1 按各科成绩进行排序，并显示排名， Score 重复时合并名次
+
+
+
+-- 16.查询学生的总成绩，并进行排名，总分重复时保留名次空缺
+
+
+
+-- 16.1 查询学生的总成绩，并进行排名，总分重复时不保留名次空缺
+
+
+
+-- 17.统计各科成绩各分数段人数：课程编号，课程名称，[100-85]，[85-70]，[70-60]，[60-0] 及所占百分比
+
+
+
+-- 18.查询各科成绩前三名的记录
+
+
+
+-- 19.查询每门课程被选修的学生数
+
+
+
+-- 20.查询出只选修两门课程的学生学号和姓名
+
+
+
+-- 21.查询男生、女生人数
+
+
+
+-- 22.查询名字中含有「风」字的学生信息
+
+
+
+-- 23.查询同名同性学生名单，并统计同名人数
+
+
+
+-- 24.查询 1990 年出生的学生名单
+
+
+
+-- 25.查询每门课程的平均成绩，结果按平均成绩降序排列，平均成绩相同时，按课程编号升序排列
+
+
+
+-- 26.查询平均成绩大于等于 85 的所有学生的学号、姓名和平均成绩
+
+
+
+-- 27.查询课程名称为「数学」，且分数低于 60 的学生姓名和分数
+
+
+
+-- 28.查询所有学生的课程及分数情况（存在学生没成绩，没选课的情况）
+
+
+
+-- 29.查询任何一门课程成绩在 70 分以上的姓名、课程名称和分数
+
+
+
+-- 30.查询不及格的课程
+
+
+
+-- 31.查询课程编号为 01 且课程成绩在 80 分以上的学生的学号和姓名
+
+
+
+-- 32.求每门课程的学生人数
+
+
+
+-- 33.成绩不重复，查询选修「张三」老师所授课程的学生中，成绩最高的学生信息及其成绩
+
+
+
+--34.成绩有重复的情况下，查询选修「张三」老师所授课程的学生中，成绩最高的学生信息及其成绩
+
+
+
+-- 35.查询不同课程成绩相同的学生的学生编号、课程编号、学生成绩
+
+
+
+-- 36.查询每门功成绩最好的前两名
+
+
+
+-- 37.统计每门课程的学生选修人数（超过 5 人的课程才统计）。
+
+
+
+-- 38.检索至少选修两门课程的学生学号
+
+
+
+-- 39.查询选修了全部课程的学生信息
+
+
+
+-- 40.查询各学生的年龄，只按年份来算
+
+
+
+-- 41.按照出生日期来算，当前月日 < 出生年月的月日则，年龄减一
+
+
+
+-- 42.查询本周过生日的学生
+
+
+
+-- 43.查询下周过生日的学生
+
+
+
+-- 44.查询本月过生日的学生
+
+
+
+-- 45.查询下月过生日的学生
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery3.sql" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery3.sql"
new file mode 100644
index 0000000..724eefd
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery3.sql"
@@ -0,0 +1,41 @@
+create database GoodsDB
+go
+create table GoodsType
+(
+	TypeID int not null primary key identity(1,1),
+	TypeName nvarchar(20) not null 
+)
+create table GoodsInfo
+(
+	GoodsID int not null primary key identity(1,1),
+	GoodsName nvarchar(20) not null,
+	GoodsColor nvarchar(20) not null, 
+	GoodsBrand nvarchar(20),  
+	GoodsMoney money not null,
+	TypeID int references GoodsType(TypeID)
+)
+insert into GoodsType(TypeName)
+select '服装内衣' union
+select '鞋包配饰' union
+select '手机数码'
+
+insert into GoodsInfo(GoodsName,GoodsColor,GoodsBrand,GoodsMoney,TypeID)
+select '提花小西装','红色','菲曼琪',300,1 union
+select '百搭短裤','绿色','哥弟',100,1 union
+select '无袖背心','白色' ,'阿依莲' ,700, 1 union
+select '低帮休闲鞋','红色', '菲曼琪' ,900, 2 union
+select '中跟单鞋','绿色', '哥弟' ,400 ,2 union
+select '平底鞋','白色', '阿依莲', 200, 2 union
+select '迷你照相机','红色' ,'尼康', 500 ,3 union
+select '硬盘','黑色' ,'希捷' ,600 ,3 union
+select '显卡','黑色' ,'技嘉',800 ,3 
+
+select * from GoodsInfo
+select * from GoodsType
+
+--3、查询价格最贵的商品名称，商品颜色和商品价格，要求使用别名显示列名
+select GoodsName 商品名称 ,GoodsColor 商品颜色,GoodsMoney 商品价格 from GoodsInfo where GoodsMoney=(select MAX(GoodsMoney) from GoodsInfo)
+--4、按商品类型编号分组查询商品最高价格，最低价格和平均价格，要求使用别名显示列名
+select TypeID,min(GoodsMoney) 最低价格,MAX(GoodsMoney) 最高价格,AVG(GoodsMoney) 平均价格 from GoodsInfo group by typeID
+--5、查询商品信息所有列，要求商品颜色为红色，价格在300~600之间
+select * from GoodsInfo where GoodsColor='红色' and GoodsMoney>=300 and GoodsMoney<600
\ No newline at end of file
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery4.sql" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery4.sql"
new file mode 100644
index 0000000..5957396
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery4.sql"
@@ -0,0 +1,53 @@
+create database HOUSE_DB
+on
+(
+	name='HOUSE_DB',
+	filename='d:\temp\HOUSE_DB_mdf',
+	size=5,
+	maxsize=50,
+	filegrowth=1
+)
+log on
+(
+	name='HOUSE_DB_log',
+	filename='d:\temp\HOUSE_DB_log_ldf',
+	size=5,
+	maxsize=50,
+	filegrowth=1
+)
+go
+create table HOUSE_TYPE
+(
+	type_id int not null primary key identity(1,1),
+	type_name varchar(50) not null,
+
+)
+create table HOUSE
+(
+	house_id int not null primary key identity(1,1),
+	house_name varchar(50) not null,
+	house_price float not null default(0),
+	type_id int not null references HOUSE_TYPE(type_id)
+)
+
+insert into HOUSE_TYPE(type_name)
+select '小户型' union
+select '经济型' union
+select '别墅'
+
+insert into HOUSE(house_name,house_price,type_id)
+select '兴国型',500,1 union
+select '小狗区',300,2 union
+select '上都会型',1500,3
+--4、添加查询
+--查询所有房屋信息
+select * from HOUSE_TYPE
+select * from HOUSE
+--使用模糊查询包含”型“字的房屋类型信息
+select * from HOUSE where house_name like '%型'
+--查询出房屋的名称和租金，并且按照租金降序排序
+select house_name 名称,house_price 租金 from HOUSE order by house_price desc
+--使用连接查询，查询信息，显示房屋名称和房屋类型名称
+select house_name,type_name from HOUSE a inner join HOUSE_TYPE b on a.house_id=b.type_id
+--查询所有房屋中月租最高的房屋，显示最高的租金和房屋名称
+select *from HOUSE where house_price=(select max(house_price) from HOUSE)
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery5.sql" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery5.sql"
new file mode 100644
index 0000000..71abe84
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/SQLQuery5.sql"
@@ -0,0 +1,39 @@
+create database StarManagerDB
+go
+use StarManagerDB
+go
+create table StarType
+(
+	T_NO int not null primary key identity(1,1),
+	T_NAME nvarchar(20)
+)
+create table StarInfo
+(
+	S_NO int not null primary key identity(1,1),
+	S_NAME nvarchar(20) not null,
+	S_AGE int not null,
+	S_HOBBY nvarchar(20),
+	S_NATIVE nvarchar(20) default('中国大陆'),
+	S_T_NO int references StarType(T_NO)
+)
+insert into StarType(T_NAME)
+select '体育明星' union
+select 'IT明星' union
+select '相声演员'
+
+insert into StarInfo(S_NAME,S_AGE,S_HOBBY,S_NATIVE,S_T_NO)
+select '梅西',30,'射门','阿根廷',1 union
+select '科比',35,'过人','美国',1 union
+select '菜景观',40,'敲代码','中国',2 union
+select '马克思',36,'造火箭','外星人',2 union
+select '郭德纲',50,'相声','中国',3 union
+select '黄铮',41,'拼多多','中国',2
+
+select * from StarInfo
+select * from StarType
+--3、查询年龄最大的3个明星的姓名，特技和籍贯信息，要求使用别名显示列名。
+select top 3 S_NAME 姓名,S_HOBBY 特技,S_NATIVE 籍贯 from StarInfo order by S_AGE desc
+--4、按 明星类型编号 分类查询   明星人数，明星平均年龄 ，显示明星人数大于2的分组信息，要求使用别名显示列名。
+select S_T_NO,count(*) 人数,AVG(S_AGE) from StarType a inner join StarInfo b on a.T_NO=b.S_T_NO  group by S_T_NO HAVING COUNT(S_NAME)>2
+--5、查询明星类型为“体育明星”中年龄最大的姓名、特技、籍贯信息，要求显示列别名。
+select S_NAME,S_HOBBY,S_NATIVE,max(S_AGE) from StarInfo a inner join StarType b on a.S_T_NO=b.T_NO where S_AGE = (select MAX(S_AGE) from StarInfo where S_T_NO = 2) group by S_NAME,S_HOBBY,S_NATIVE
\ No newline at end of file
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo1.java" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo1.java"
new file mode 100644
index 0000000..f545794
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo1.java"
@@ -0,0 +1,35 @@
+package less;
+
+import java.util.Scanner;
+
+public class demo1 {
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+		//* 需求：设计一个方法用于获取数组中元素的最大值 
+		//
+		//* 思路：
+		
+		//* ①定义一个数组，用静态初始化完成数组元素初始化
+		//* ②定义一个方法，用来获取数组中的最大值，最值的认知和讲解我们在数组中已经讲解过了
+		//* ③调用获取最大值方法，用变量接收返回结果
+		//* ④把结果输出在控制台
+		//////////////
+		Scanner scan = new Scanner(System.in);
+		
+		int c=fangfa();
+		System.out.println(c);
+	}
+
+	public static int fangfa() {
+		int [] d=new int [] {99,100,65,75,80,94,92};
+		int max;
+		max=d[0];
+		for (int i = 0; i < d.length; i++) {
+			if (max<d[i]) {
+				max=d[i];
+			}
+		}
+		return max;
+	}
+}
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo2.java" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo2.java"
new file mode 100644
index 0000000..da910a8
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo2.java"
@@ -0,0 +1,16 @@
+package less;
+
+public class demo2 {
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+//		需求：设计一个方法用于数组遍历，要求遍历的结果是打印输出在一行上的。例如：[11, 22, 33, 44, 55] 
+		a();
+	}
+	public static void a() {
+		 int a[]=new int[] {11,22,33,44,55};
+		 for (int i = 0; i < a.length; i++) {
+			System.out.print(a[i]+", ");
+		}
+	}
+}
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo3.java" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo3.java"
new file mode 100644
index 0000000..fff4c44
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo3.java"
@@ -0,0 +1,40 @@
+package less;
+
+public class demo3 {
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+//		- 需求：设计一个方法，该方法能够同时获取数组的最大值，和最小值
+//
+//		- 注意: return语句, 只能带回一个结果.
+//
+//		- 提示:返回一个数组，数组里第一个元素是最大值，第二个元素是最小值
+		int[] p = fangfa();
+		System.out.println("最大值"+p[0]);
+		System.out.println("最小值"+p[1]);
+	}
+
+	public static int[] fangfa() {
+		int[] d = new int[] { 99, 100, 65, 75, 80, 94, 92 };
+		int max;
+		max = d[0];
+		for (int i = 0; i < d.length; i++) {
+			if (max < d[i]) {
+				max = d[i];
+			}
+		}
+		int min;
+		min = d[0];
+		for (int i = 0; i < d.length; i++) {
+			if (min > d[i]) {
+				min = d[i];
+			}
+		}
+		int e[] = new int[2];
+		e[0] = max;
+		e[1] = min;
+		return e;
+
+	}
+
+}
diff --git "a/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo4.java" "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo4.java"
new file mode 100644
index 0000000..98eda5c
--- /dev/null
+++ "b/\346\226\271\346\263\225\347\273\203\344\271\240/\346\270\251\345\271\277\347\224\237/demo4.java"
@@ -0,0 +1,18 @@
+com.array.test;
+
+import java.util.Arrays;
+import java.util.Scanner;
+
+//实现：在有序数组中插入一个元素
+// 对新数组排序---直接使用Arrays.sort()方法
+public class ArrayInsertTwo {
+    public static void main(String[] args) {
+        int[] arr=new int[]{5,8,19,20,23};
+        System.out.println("原数组为：arr="+ Arrays.toString(arr));
+        Scanner sc=new Scanner(System.in);
+        System.out.println("请输入插入的数据");
+        arr[arr.length-1]=sc.nextInt();   //把要插入的数据放到数组的最后一个
+        Arrays.sort(arr);
+        System.out.println("新数为：arr="+ Arrays.toString(arr));
+    }
+}    
\ No newline at end of file
-- 
Gitee