SQL视图、存储过程、触发器、游标及完整性

实验之前最好重新建一个数据库,记得改路径
这个可以查SQL的基本语句https://www.runoob.com/sql/sql-tutorial.html

USE [master]
GO

/****** Object:  Database [xscj]    Script Date: 2020/2/21 16:42:38 ******/
CREATE DATABASE [xscj]
 CONTAINMENT = NONE
 ON  PRIMARY 
( NAME = N'XSCJ_Data', FILENAME = N'home\learn\xscj.mdf' , SIZE = 8192KB , MAXSIZE = UNLIMITED, FILEGROWTH = 10%)
 LOG ON 
( NAME = N'XSCJ_Log', FILENAME = N'home\learn\xscj_log.ldf' , SIZE = 1024KB , MAXSIZE = 2048GB , FILEGROWTH = 10%)
GO

USE [xscj]
GO
/****** Object:  Table [dbo].[COU]    Script Date: 2020/2/21 16:42:38 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

DROP TABLE SC
GO
DROP TABLE COU
GO
DROP TABLE STU
GO
DROP TABLE MAJOR
GO


CREATE TABLE dbo.COU(
	CNO char(4) NOT NULL,
	CNAME varchar(30) NOT NULL,
	CREDIT smallint NULL,
	PTIME char(5) NULL,
	TEACHER nchar(10) NULL,
 CONSTRAINT PK_COU PRIMARY KEY CLUSTERED 
(
	CNO ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON PRIMARY
GO
/****** Object:  Table [dbo].[MAJOR]    Script Date: 2020/2/21 16:42:38 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE major(
	mno char(2) NOT NULL,
	mname varchar(20) NOT NULL,
 CONSTRAINT PK_MAJOR PRIMARY KEY CLUSTERED 
(
	mno ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON PRIMARY
GO
/****** Object:  Table [dbo].[SC]    Script Date: 2020/2/21 16:42:38 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE sc(
	sno char(4) NOT NULL,
	cno char(4) NOT NULL,
	grade numeric(6, 1) NULL,
 CONSTRAINT [PK_SC] PRIMARY KEY CLUSTERED 
(
	[SNO] ASC,
	[CNO] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[STU]    Script Date: 2020/2/21 16:42:38 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE stu(
	sno char(4) NOT NULL,
	sname char(8) NOT NULL,
	sex int NULL,
	mno char(2) NULL,
	birdate smalldatetime NULL,
	memo text NULL,
 CONSTRAINT [PK_STU] PRIMARY KEY CLUSTERED 
(
	[SNO] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
ALTER TABLE stu   ALTER COLUMN sex SET DEFAULT 1;

GO
ALTER TABLE sc WITH NOCHECK ADD  CONSTRAINT FK_CNO FOREIGN KEY(cno)
REFERENCES cou (cno)
GO
ALTER TABLE [dbo].[SC] CHECK CONSTRAINT [FK_CNO]
GO
ALTER TABLE cou  ADD   CHECK  ((credit>=0 AND credit<=20))
GO
ALTER TABLE [dbo].[COU] CHECK CONSTRAINT [ck_credit]
GO
USE [master]
GO
ALTER DATABASE [xscj] SET  READ_WRITE 
GO

USE xscj
GO

insert cou  values ( 'C001','高等数学',8,'1','孙老师');
insert cou values ( 'C002','C语言',5,'2','张老师');
insert cou values ( 'C003','数据结构',4,'3','张老师');
insert cou  values ( 'C004','操作系统',3,'4','罗老师');
insert cou values ( 'C005','组成原理',4,'3','陈老师');
insert cou  values ( 'C006','数据库原理',3,'5','吴老师');
insert cou  values ( 'C007','JAVA程序设计',3,'3','李老师');


insert major values ( '01','计算机工程');
insert major  values ( '02','软件工程');
insert major  values ( '03','网络工程');
insert major  values ( '04','智能技术');

insert stu  values ( 'S001','张三',1,'01','2001-10-01 00:00:00.000','二年级，荣获学院三好学生');
insert stu  values ( 'S002','李四 ',0,'02','2001-05-13 00:00:00.000',NULL);
insert stu  values ( 'S003','李芳  ',0,'01','2000-05-11 00:00:00.000',NULL);
insert stu  values ( 'S004','张明 ',1,'02','2002-05-31 00:00:00.000','一年级，荣获优秀学生干部');
insert stu  values ( 'S005','张强  ',1,'02','2001-06-01 00:00:00.000',NULL);
insert stu  values ( 'S006','吴玲 ',0,'02','2000-06-11 00:00:00.000',NULL);
insert stu  values ( 'S007','郑奇 ',1,'01','2000-06-11 00:00:00.000',NULL);
insert stu  values ( 'S008','吴丽丽',0,'03','2001-06-17 00:00:00.000',NULL);
insert stu  values ( 'S009','林森 ',1,'03','2002-01-10 00:00:00.000',NULL);
insert stu  values ( 'S010','徐小宜 ',1,'04','2003-05-11 00:00:00.000',NULL);

insert sc  values ( 'S001','C001',68.6);
insert sc  values ( 'S001','C002',95.5);
insert sc  values ( 'S001','C003',74.5);
insert sc  values ( 'S002','C001',70.0);
insert sc  values ( 'S002','C002',86.1);
insert sc  values ( 'S003','C001',89.3);
insert sc  values ( 'S003','C005',78.8);
insert sc  values ( 'S003','C006',67.6);
insert sc  values ( 'S004','C002',67.6);
insert sc  values ( 'S004','C004',50.2);
insert sc  values ( 'S005','C002',80.9);
insert sc  values ( 'S010','C001',NULL);


select * from sc
select * from cou
select * from stu
select * from major

1.视图的创建与应用
基本概念
为表 sc创建一个视图，包括有各个学生学号、选修课程的门数及平均分,如：
create view s_grade(sno,c_num,avg_grade)
as
select sno,count(cno),avg(grade) from sc group by sno

实践下列查询和更新操作的功能，是否出错，若可运行，写出转换至基本表SC上的相应操作。若不可运行，说明原因
(1)select * fr
(2)om s_grade;

(3)select sno,c_num from s_grade where avg_grade>80

(4)select sno,avg_grade from s_grade where c_num>(select c_num from s_grade where sno=’S004’)

(5)update s_grade set c_num=c_num+2

(5)delete from s_grade where c_num>3

2．对SC表创建视图COMPUTER_SC，该视图包括‘01’专业的学生的学号、姓名与性别
设计实验完成该视图数据的查询、添加、修改与删除。进一步理解行列子集视图与非行列子集视图应用上的区别

create view  COMPUTER_SC 
as select sno, sname, sex from stu where mno = '01'

select * from COMPUTER_SC;
insert into COMPUTER_SC values('S012', '叶华', '1')

update COMPUTER_SC set sname = '花生酱' where sno = 'S001'


delete from COMPUTER_SC where sno = 'S001'

3．T-SQL
1）使用CASE WHEN
查询学生的所有信息，若性别为1，则性别显示‘男’，否则显示‘女’

select * , '性别' = case when sex = 1 then '男' else '女' end from stu

2）使用WHILE及游标等
游标概念用法请戳
对SC表添加一个等级列，若学生成绩80及以上等级A，70-79分为B，其余为C，null仍为null


declare @sno char(4),@cno char(4),@grade numeric(6, 1),@rank char(1)
declare sc_cur1 cursor
	for
		select *
		from sc
open sc_cur1
while(@@fetch_status=0)
begin
	fetch next from sc_cur into @sno,@cno,@grade
	if(@grade>=80) set @rank='A'
	else if(@grade>=70 and @grade<70) set @rank='B'
	else if(@grade is null) set @rank=null
	else set @rank='C'
	select sno=@sno,cno=@cno,grade=@grade,rank=@rank
end
close sc_cur1
deallocate sc_cur1

3）使用WHILE及游标
在XSCJ数据库运行如下脚本，
Create table sumcredit(sno char(4) primary key,sum_credit numeric(4,1))
Insert into sumcredit select sno,0 from stu
使用游标完成每个学生的总学分，并更新入sumcredit表中。只有60分及以上才可获得课程学分。


deallocate sum_cur
declare @sno char(4), @sum numeric(4,1)
declare sum_cur cursor for 
select sno, sum(credit) from sc left outer join cou on sc.cno = cou.cno and  sc.grade >=60 group by sc.sno
open sum_cur
fetch next from sum_cur into @sno, @sum
while(@@FETCH_STATUS = 0)
begin
	fetch next from sum_cur into @sno, @sum 
	update sumcredit set sum_credit = @sum where sumcredit.sno = @sno
end
close sum_cur
select * from sumcredit

4．据SQL SERVER提供的完整性完成完整性实践
SQL SERVER提供的数据库完整性包括域完整性(CHECK,DEFAULT,UNQUE,RULE，用户自定义类型、基本数据类型)、表间完整性（复习实体完整性、参照完整性的定义与验证）、复杂完整性表达（触发器）
1）创建stu1,major1表，表的结构与xscj数据库的的stu及major一致。在创建与修改表结构的过程中应用好以上完整性概念
2）插入数据，说明实体完整性与参照完整性的检查机制。删除数据说明参照完整性的检查机制。截图说明

3）对STU1表任意插入一条数据，该数据违背了你所定义的所有完整性规则。分别说明违背了什么，并截图

完整性概念

2）创建一个用户自定义类型，用于定义MAJOR1表与STU1表的mno(提示：查看帮助CREATE TYPE 、CREATE RULE，SP_BINDRULE,SP_UNBINDRULE等) 专业号由M开头，其余字符为数字字符，长度为2.

sno like ‘S[0-9][0-9]’

5、存储过程创建与使用
1）创建存储过程P1，查询学生表所有信息；运行之。

create procedure p1 as select * from stu
p1

2）创建存储过程P2，查询某学号学生的所有信息，运行

create procedure p2 @sno char(4) as select * from stu where sno = @sno
p2 'S001';

3）创建存储过程P3，查询某学号学生的姓名及所就读专业，运行之

create procedure p3 @sno char(4) as select sname, mname from stu, major where sno = @sno and stu.mno = major.mno

p3 'S001';

4）创建存储过程P4，查询某课程名的平均分，选课人数并输出之。运行之


create procedure p4 @cname varchar(30) as select cname, avg(grade) from sc, cou 
where sc.CNO = cou.cno and cname = @cname group by cname

p4 '高等数学'

5）创建存储过程P5，完成该生的退学业务处理（即删除某学号学生的所有信息），运行之。

create procedure p5 @sno char(4) as
delete sc from sc where sno = @sno
delete stu from stu where sno = @sno

p5 'S013'

6）创建存储过程P6，完成为某学号学生插入两条选课记录（注意不能插入重复的选课记录），并返回统计当前选修了几门课。运行之


create procedure p6 @sno char(4) as
insert into sc values(@sno, 'C004', 99)
insert into sc values(@sno, 'C005', 66)
select count(cno) as sumcno from sc where sno = @sno group by sno
p6 'S009'
--drop procedure p6

7)创建存储过程P7，返回每个学生的平均分。运行之

create procedure p7 as
select sno, avg(grade) from sc group by sno

p7

8)创建存储过程P8，完成学生状态处理，若学生75分以下课程数超过其75分以上的课程数，则留级，否则标注为升学,运行之
提示：存储过程创建可参考CREATE PROCEDURE的帮助。

create procedure p8 as
select distinct sno, sname, '状态' = case when
(select count(grade) from sc where grade >= 60 and sno = stu.sno) 
>=
(select count(grade) from sc where grade < 60 and sno = stu.sno)
then '正常' 
else '留级'
end
from stu
p8

6．触发器应用
触发器（create trigger）
1）创建触发器，实现对SC表插入一条记录，若该选课记录存在则提示插入错，否则插入该记录。用插入成功与插入失败的两个截图说明触发器如何工作。
触发器是一种特殊的存储过程，它不能被显式地调用，而是在往表中插入记录﹑更新记录或者删除记录时被自动地激活。所以触发器可以用来实现对表实施复杂的完整性约束。
触发器基础知识

触发器用法

create trigger cr_sc on sc after insert as 
begin tran tran_sc
declare @sno varchar(4)
declare @cno varchar(4)
declare @cnt int
set @sno = (select sno from inserted)
set @cno = (select cno from inserted)
set @cnt = (select count(cno) from sc where sno = @sno and cno = @cno group by sno)
if(@cnt >= 2)
begin 
print '已存在该选课'
rollback tran
end
else begin
print '选课成功'
commit tran
end

2）创建触发器，实现每门课最多只能8个学生选修。


create trigger tri_sc on sc
after insert 
as 
begin tran p_num
declare @cno varchar(4)
declare @cnt int
set @cnt = (select count(sno) from sc where cno = @cno)
if(@cnt >= 8)
begin
print '选课人数已达上限，请选择其他课程'
rollback tran
end
else begin 
print '选课成功'
commit tran 
end

3）创建触发器，实现每个学生最多选修5门课.

create trigger t_sc on sc 
after insert 
as
begin tran p_num
declare @sno varchar(4) 
declare @cnt int 
set @sno = (select sno from inserted)
set @cnt = (select count(cno) from sc where sno = @sno)
if(@cnt >= 5)
begin 
print '你的选课已达上限'
rollback tran
end
else begin
print '选课成功'
commit tran
end

4）创建触发器，实现删除STU表某学生的记录，注意完整性概念保证，使用用instead of
instead of 用法


create trigger del_stu on stu
instead of delete
as begin 
delete stu where sno = (select sno from deleted)
delete sc where sno =(select sno from deleted)
end

5）创建触发器，实现“男子汉的培养”课程限男生选修。（注：在课程表中添加一条记录“男子汉的培养”）


create trigger man_sc on sc
after insert 
as
begin tran p_num
declare @sno varchar(4)
declare @sex bit
declare @cno varchar(4)
set @sno = (select sno from inserted)
set @sex = (select sex from stu where sno = @sno)
set @cno = (select cno from inserted)
if @sex = 1 and @cno = (select cno from cou where cname = '男子汉培养' )
begin 
print '选课成功'
commit tran 
end
else begin
print '男生才能选'
rollback tran
end

7．综合应用：
设系统增加一个需求，为stu表添加一个sum_credit字段，填写该字段的数值
（提示：原已选修的课程所获得的学分必须计算统一，以后每选修一门课，若成绩满足>=60分条件则获得自动获取该课程学分）

Alter table stu add sum_credict;
insert into stu
select sum(credit) 
from (
select stu.sno,(case when grade>=60 then credit else 0 end) credit
from stu
left join sc on stu.sno=sc.sno 
left join cou on sc.cno=cou.cno) a
group by sno

思考题：
为以下录入记录要求设计界面，可以使用java、net或javascript实现后截图
为stu设计录入界面，并编程实现之

为COU表设计录入界面，并编程实现之

为SC表设计录入界面,并编程实现之
要求：附界面及运行结果。

如有错误,请指出

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