-------------------------新建数据库-------------------------------
create database stuDB
on primary
(
name='stuDB_data',
filename='D:数据库stuDB_data.mdf',
size=5mb,
maxsize=100mb,
filegrowth=15%
)
log on
(
name='stuDB_log',
filename='D:数据库stuDB_log.idf',
size=2mb,
filegrowth=1mb
)
go
--------------------------新建表stuinfo------------------------------------
use stuDB
go
create table stuinfo
(
stuName varchar(20) not null,
stuNo char(6) not null,
stuAge int not null,
stuID numeric(18,0),
stuAddress text
)
go
--------------------------新建表stumarks-------------------------------------------------
create table stumarks
(
stuNo char(6) not null,
stuWritten int not null,
stuMachine int not null
)
Go
====================语句约束================================
===========================================================
-----------------------------主键约束-------------------------------------
Alter（改） table stuinfo
add constraint（约束） PK_stuNo primary key(stuNo)
------------------------------唯一约束-------------------------------------
alter table stuinfo
add constraint UQ_stuID unique(stuID)
-------------------------------检查约束------------------------------------
alter table stuinfo
add constraint CK_stuAge check(stuAge between 15 and 40)
-------------------------------默认约束------------------------------------
alter table stuinfo
add constraint DF_stuAddress default'地址不详' for stuAddress
-------------------------------外键约束------------------------------------
alter table stumarks
add constraint FK_stuNo foreign key(stuNo) references （指向）stuinfo(stuNo)
Go
========================================================
---------------------------------数据操作语言--------------------------------------------
========================================================
use stuDB
select *from stuinfo
insert into stuinfo values ('小红','004',23,12345,default)--增加一行
insert into stuinfo (stuName,stuNo ,stuAge ,stuID ,stuAddress ,sex )values('四风','005',23,'12347','济南','男')-----------增加一行
update stuinfo set stuAddress ='如皋' where stuNo =004--修改
delete from stuinfo where stuNo =004--删除一行
create table student----------新建表
(
stuName varchar(20) null,
stuNo char(6) null,
stuAge int null,
stuID numeric(18, 0) null,
stuAddress text null
)
select * from student
insert into student (stuName,stuNo,stuAge,stuID,stuAddress)
select stuName,stuNo,stuAge,stuID,stuAddress from stuinfo----插入多行（类似复制，需提前建表）
delete from student where stuNo =1---------------删除学号为的学生
delete from student -------------删除student整张表(一行一行删除)，但表结构还在（不删除标识列）
drop table student------------删除student整张表
select * into students from stuinfo ---------------复制表stuinfo到students中，不用提前建表
select * from students
truncate table students-----------------删除表，一下子释放存储空间，标识列从初始开始，表结构还在
drop table students----------------删除整张表，表结构
select * from tel
select * from tel group by code having COUNT(code)>1-------------查找tel表中code列重复的行
select * from stuinfo
//select '性别' as sex from stuinfo ----------虚拟表中添加列sex
alter table stuinfo add sexi char-------------增加一列
alter table stuinfo drop column sexi -----------------删除一列
========================select查询语句=====================================
use stuDB
select * from stuinfo
select * from stumarks
alter table stuinfo add sex char-----------插入一行sex
insert into stuinfo (stuName,stuNo ,stuAge ,stuID ,stuAddress ,sex )values('四风','005',23,'12347','济南','男')------插入一行
update stuinfo set sex='男' where stuNo =001----------修改性别
update stuinfo set sex='女'where stuNo=002
update stuinfo set sex='女'where stuNo=003
select * from stuinfo where sex='男'----------查找男学员
select * from stumarks where stuWritten between 75 and 100----------查找笔试成绩优秀学员
select SUM(stuwritten) as 笔试总成绩,SUM (stuMachine ) as 机试总成绩 from stumarks -------------统计笔试总成绩,机试总成绩
select count(stuNo) as 学员人数,avg(stuwritten) as 笔试平均分,avg(stuMachine) as 机试平均分 from stumarks ----------统计本次参加人数，笔试平均分，机试平均分
select stuNo as 没有通过的人 from stumarks where stuWritten <60 or stuMachine <60---------查找考试没有通过的人
select stuNo as 学号,stuwritten as 笔试成绩,stuMachine as 机试成绩 from stumarks ----------查询并显示学员学号，笔试成绩，机试成绩
update stumarks set stuwritten=stuWritten +5,stuMachine=stuMachine +5
update stumarks set stuMachine=100 where stuMachine>100
update stumarks set stuWritten =100 where stuWritten >100
select * from stumarks ---------------要求每个学生加分，最高分为100
======================两表之间关联========================================
select users.userName ,users.userId ,account .score ---------
from users left join account --------------------------------
on users.userId =account.userId ------------=========-多表联结(左外关联得左表的全部和右表匹配的号)
select * from users left join account on users.userId=account .userId
select users .*,account .* from users left join account on users.userId=account .userId
insert into account (users.userId ,score )
select users.userId ,'2'from users left join account on users.userId =account .userId
where account .score is null------------查找account中无记录的人并插入信息
=======================作业练习=====================================
已知有如下三个表:
S (sno,sname) 学生表。SNO 为学号，SNAME 为姓名
C (cno,cname,cteacher) 课程表。cno 为课程号，cname为课程名，cteacher为任课教师
SC(sno,cno,score) 选课表,记录学员选修的课程与成绩。sno为学号(S表中sno的外键)，cno为课程号(C表中cno的外键)， score为成绩
use stuDB
select * from S
select * from C
select * from SC
alter table sc
add constraint FK_sno foreign key(sno) references s(sno)
alter table sc
add constraint fk_cno foreign key(cno) references c(cno)
问题一：列出所有选过课程学员的学号、姓名、所选课程名称、成
绩、任课老师
select S.sno,S.sname,C.cname,C.cteacher,SC.score from SC
left join S on S.sno=SC.sno
left join C on SC.cno=C.cno
问题２：列出所有选修＂基础会计学＂的学员学号、姓名
select sno,sname from s where sno in
(select sc.sno from sc left join c on sc.cno=c.cno where
c.cname='基础会计学')
问题３：找出成绩不合格的学员，列出其学号、姓名、不合格课程
名称、分数、任课老师
select S.sno,S.sname,C.cname,C.cteacher,SC.score from SC
left join S on S.sno=SC.sno
left join C on SC.cno=C.cno where sc.score<60
问题４：找出有一门或多门成绩不合格的学员，并将其所有参考课
程名称、任课老师、姓名、成绩
按成绩从低到高的顺序列出
select S.sname,C.cname,C.cteacher,SC.score from SC left
join S on S.sno=SC.sno
left join C on SC.cno=C.cno where sc.score<60 order by
sc.score asc
问题５：找出同时选修课程号为＂C１＂和＂C２＂的学员姓名
select sname from s where sno in
(select sno from sc where cno='c1')
(select sno from sc where cno='c2')
问题６：列出没有选修过“李明”老师讲授课程的所有学生姓名
select sname from s where sno in
(select sc.sno from sc left join c on sc.cno=c.cno where
c.cteacher='李明')
问题７：列出有二门以上(含两门)不及格课程的学生姓名及其平均
成绩
select s.sname ,avg(convert(int,sc.score)) from s left join
sc on s.sno=sc.sno group by s.sname having count(sname)>2
问题8：列出所有学生的姓名及平均成绩
select s.sname ,avg(convert(int,sc.score)) from s left join
sc on s.sno=sc.sno group by s.sname
====================视图作业========================================
use stuDB
alter table stumark
add constraint FK_stuno foreign key (stuno) references student(stuno)
select * from student
select* from stumark
create view student_stumark
as
(select stuname as '姓名',student .stuno as '学号',笔试成绩
=case
when writtenexam IS NULL then '缺考'
else writtenexam
end
,机试成绩
=case
when labexam IS null then '缺考'
else labexam
end,
是否通过=case
when writtenexam<60 or labexam<60 or writtenexam IS NULL or labexam is null then '0'
else '1'
end
from student left join stumark on student .stuno =stumark .stuno) ------------中间表
select * from student_stumark--------------查询视图表
select count(student.stuno ) as '应到人数',count(examno) as '实到人数',
缺考人数= count(student.stuno )-count(examno)
from student left join stumark on student.stuno =stumark.stuno ---------------上面表
select count(*) as '总人数',sum(convert(int,是否通过)) as '通过人数',
convert(varchar(20),(sum(convert(int,是否通过))*100/count(*)))+'%' as 通过率
from student_stumark-------------最后一个表
============================视图、事务、存储过程=================
===============================================================
create table card--创建card表
(
id varchar(10) primary key,--卡号
userName varchar(10) not null,--用户姓名
balance money not null--用户余额
)
drop table account
create table account--创建account表
(
id int primary key identity,--交易编号
cardId varchar(10) not null,--卡号
tradeType char(1) ,--交易类型
number money --操作的金额
)
---------------添加约束----------------
alter table card drop constraint CK_balance
alter table card -- 检查约束，card 表中balance
add constraint CK_balance
check(balance>0)
alter table account drop constraint FK_cardId
alter table account--外键约束，两个 表中的cardId
add constraint Fk_cardId
foreign key(cardId) REFERENCES card(id)
--------------------向card表中添加信息---------------------
insert into card(id,userName,balance) values('C001','张三',1235)
select * from card
-------------------向account表中添加数据-------------------------
insert into account(cardId,tradeType,number)values('C001','0',100)
insert into account(cardId,tradeType,number)values('C011','0',100)
--delete from account
select * from account
----1、创建银行卡信息视图（字段都为中文）
go
create view view_card
as
select id as 卡号, userName as 用户姓名,balance as 余额 from card
select * from view_card
---2、交易信息表视图，含卡号，用户姓名，交易类型，交易金额，现有余额等字段
go
create view view_card_account
as
select card.id as 卡号,userName as 用户姓名,tradeType as 交易类型,number as 交易金额,
balance as 现有余额 from account
inner join card on card.id = cardId
select * from view_card_account
go
--3、创建存钱或取钱的存储过程；接收两个参数，第一个为交易类型，第二个为交易金额
create proc proc_account
@cardId nvarchar(10),
@tradetype int,
@number money
as
declare @balance int
if(@tradetype=1)
begin
select @balance=balance from card where id=@cardId
update card set balance=@number+@balance where id=@cardId
end
else
begin
select @balance= balance from card where id=@cardId
if(@balance<=@number)
begin
raiserror ('您的余额不够',12,5)
return
end
update card set balance=balance-@number where id=@cardId
end
go
go
exec proc_account C001,1,500
exec proc_account C001,0,400
select *from card
--4、创建开户存储过程；接收三个参数，分别为卡号，用户姓名和开卡金额，可向card表添加一条记录
create proc proc_insert
@cardId nvarchar(10),
@userName nvarchar(10),
@number money
as
if(@number<=0)
begin
raiserror ('不符合要求',10,6)
return
end
else
begin
insert into card(id,userName,balance) values(@cardId,@userName,@number)
end
exec proc_insert C012,hhhh,12.10
select * from card
--5、创建转账事务存储过程 接收三个参数，分别为转出卡号，转入卡号，转账金额。要求用事务控制。
create proc proc_inout
@incardId varchar(10),
@outcardId varchar(10),
@number money
as
declare @inputcard money,
@outputcard money
select @inputcard=balance from card where id=@incardId
if(@inputcard<@number)
begin
raiserror ('钱不够',16,1)
return
end
else
begin
select @outputcard =balance from card where id=@outcardId
update card set balance=@inputcard-@number where id=@incardId
update card set balance=@outputcard+@number where id=@outcardId
end
exec proc_inout C001,C002,100
select *from card
===========================自定义函数==============================
在stuInfo表中操作
创建自定义函数实现模糊查询，指定字符串初始部分，只要查询的结果是以指定字符串开头，都可查询出来
自己给stuInfo表添加一个字段province,代表学生所在省份，写SQL语句实现如下结果：
create function stuin(@code nvarchar(10))
returns table---返回一个表即不用转换类型
as
return (select stuName,score from stuinfo
where stuName like @code+'%')
select * from stuin('R')