From 96995a1475c1cc24b3ec67fb489af23cc9faf534 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?09=E9=99=88=E7=83=BD=E6=9D=B0sql=E8=BF=9B=E9=98=B6?=
 <3241892760@qq.com>
Date: Wed, 21 Sep 2022 12:18:44 +0800
Subject: [PATCH] =?UTF-8?q?=E6=8F=90=E4=BA=A4?=
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Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../9.20\346\270\270\346\240\207.md"          | 193 ++++++++++++++++++
 .../9.20\346\270\270\346\240\207.md"          |  72 +++++++
 2 files changed, 265 insertions(+)
 create mode 100644 "09\351\231\210\347\203\275\346\235\260/\344\275\234\344\270\232/9.20\346\270\270\346\240\207.md"
 create mode 100644 "09\351\231\210\347\203\275\346\235\260/\347\254\224\350\256\260/9.20\346\270\270\346\240\207.md"

diff --git "a/09\351\231\210\347\203\275\346\235\260/\344\275\234\344\270\232/9.20\346\270\270\346\240\207.md" "b/09\351\231\210\347\203\275\346\235\260/\344\275\234\344\270\232/9.20\346\270\270\346\240\207.md"
new file mode 100644
index 0000000..cecda47
--- /dev/null
+++ "b/09\351\231\210\347\203\275\346\235\260/\344\275\234\344\270\232/9.20\346\270\270\346\240\207.md"
@@ -0,0 +1,193 @@
+```
+create database STUDENTS
+go
+use STUDENTS
+go
+
+CREATE TABLE tb_student (
+	stu_num char(8) primary key,
+	name char(20) NOT NULL,
+	gender bit DEFAULT NULL,
+	birth date DEFAULT NULL,
+	school char(20) DEFAULT NULL,
+	major char(20) DEFAULT NULL,
+);
+go
+insert into tb_student values('16100101','马诗',1,'1998-03-16','理学院','统计');
+insert into tb_student values('16130201','博文',0,'1998-04-24','信息学院','计算机科学与技术');
+insert into tb_student values('16130203','魏波',1,'1998-10-29','信息学院','计算机科学与技术');
+insert into tb_student values('16130205','黄弘',1,'1998-08-06','信息学院','数据科学与大数据技术');
+insert into tb_student values('17100104','易高明',0,'1999-05-29','理学院','信息与计算科学');
+insert into tb_student values('17100105','万承承',0,'1999-09-11','理学院','信息与计算科学');
+insert into tb_student values('17110101','黄弘',0,'2000-07-25','文法学院','法学');
+insert into tb_student values('17130202','邹睿睿',1,'1998-06-29','信息学院','计算机科学与技术');
+insert into tb_student values('17130204','马又云',1,'1999-03-27','信息学院','数据科学与大数据技术');
+insert into tb_student values('18100103','邓承明',1,'2000-07-25','理学院','信息与计算科学');
+
+
+CREATE TABLE tb_inf_student(
+	stu_num char(8) primary key foreign key references tb_student(stu_num),
+	hobby	varchar(120) DEFAULT NULL,
+	speciality	varchar(120) DEFAULT NULL,
+	ori_loca	char(16) DEFAULT NULL,
+	prize int DEFAULT NULL,
+);
+go
+
+insert into tb_inf_student values('16100101','听音乐','艺术特长','北京',2);
+insert into tb_inf_student values('16130201','看小说',null,'湖南',3);
+insert into tb_inf_student values('16130203','硬笔书法','艺术特长','新疆',1);
+insert into tb_inf_student values('16130205','听音乐','艺术特长','北京',2);
+insert into tb_inf_student values('17100104','打篮球',null,'北京',3);
+insert into tb_inf_student values('17100105','编程','科技特长','北京',2);
+insert into tb_inf_student values('17110101','打篮球','科技特长','河北',2);
+insert into tb_inf_student values('17130202','编程','科技特长','天津',3);
+insert into tb_inf_student values('17130204','看电影',null,'北京',1);
+insert into tb_inf_student values('18100103',null,null,'河南',null);
+go
+
+
+CREATE TABLE tb_bibliography (
+	ISBN char(13) primary key,
+	name char(32) DEFAULT NULL,
+	author char(32) DEFAULT NULL,
+	publishing char(32) DEFAULT NULL,
+	pub_time date DEFAULT NULL,
+	intro varchar(200) DEFAULT NULL,
+	category char(8) DEFAULT NULL,
+	price money DEFAULT NULL,
+);
+go
+
+insert into tb_bibliography values('7040409659','大学计算机','李凤霞','高等教育出版社','2014','教育部大学计算机课程改革项目规划教材','TP',28);
+insert into tb_bibliography values('7301046065','刑法学','高明轩','北京大学出版社','2000','刑法_法学高等学校中国教材','O',69);
+insert into tb_bibliography values('7806553312','射雕英雄传','金庸','广州出版社','2018','金庸作品集','I',67.9);
+insert into tb_bibliography values('9788020002207','红楼梦','曹雪芹','人民文学出版社','2008','学术研究或个人阅读都非常合适','I',31.25);
+insert into tb_bibliography values('9787113254100','Python语言及其应用','赵广辉','中国铁道出版社','2019','本书介绍Python语言的基础知识及其在各个领域的具体应用','TP',62.2);
+insert into tb_bibliography values('9787115266156','管理信息系统实用教程(第2版)','王若宾','人民邮电出版社','2012','普通高等教育\十一五\国家级规划教材','TP',36);
+insert into tb_bibliography values('9787115356840','管理信息系统实用教程(第3版)','王若宾','人民邮电出版社','2015','普通高等教育\十一五\国家级规划教材','TP',45);
+insert into tb_bibliography values('9787302252955','人工智能:一种现代的方法(第3版)','黄今夏','清华大学出版社','2011','《人工智能:一种现代的方法(第3版)》为大学计算机教育著名教材系列之一','TP',132.6);
+insert into tb_bibliography values('9787513030953','信息论','田甜','知识产权出版社','2015','文理科公选课指定教材','TP',126);
+insert into tb_bibliography values('9787569302585','计算统计(第2版)','冯新奇','西安交通大学出版社','2018','本书涵盖了计算统计的所有核心内容','TP',67.5);
+insert into tb_bibliography values('9789113268712','新编数据库技术','王若宾','中国铁道出版社','2018','本书重构了课程内容结构','TP',38.5);
+
+
+
+CREATE TABLE tb_book(
+	barcode char(9) primary key,
+	ISBN char(13) foreign key references tb_bibliography(ISBN),
+	[status] bit default null,
+);
+
+insert into tb_book values('O924.01','7301046065',0);
+insert into tb_book values('O924.02','7301046065',1);
+insert into tb_book values('O924.03','7301046065',1);
+insert into tb_book values('I13.212','9788020002207',1);
+insert into tb_book values('I13.213','9788020002207',1);
+insert into tb_book values('I247.56','7806553312',1);
+insert into tb_book values('I247.59','7806553312',0);
+insert into tb_book values('TP122.32','9787569302585',1);
+insert into tb_book values('TP122.33','9787569302585',1);
+insert into tb_book values('TP311.11','9787113254100',1);
+insert into tb_book values('TP311.12','9787113254100',0);
+insert into tb_book values('TP311.13','9787115356840',1);
+go
+
+
+CREATE TABLE tb_record(
+	rid int primary key identity(1,1),
+	stu_num char(8) references tb_student(stu_num),
+	barcode char(9) references tb_book(barcode),
+	borrow_time datetime DEFAULT NULL,
+	return_time datetime DEFAULT NULL,
+);
+go
+
+insert into tb_record values('16130203','I247.56','2019-04-09','2019-04-13');
+insert into tb_record values('17130204','I247.56','2019-04-15','2019-04-17');
+insert into tb_record values('16130205','I247.59','2019-04-17','2019-04-20');
+insert into tb_record values('16100101','I247.56','2019-04-17','2019-04-18');
+insert into tb_record values('17100105','TP311.11','2019-04-29',null);
+insert into tb_record values('16130201','I247.59','2019-05-01','2019-05-20');
+insert into tb_record values('17130202','TP311.12','2019-05-03',null);
+insert into tb_record values('18100103','I13.212','2019-05-04','2019-05-15');
+insert into tb_record values('18100103','I13.213','2019-05-20','2019-05-30');
+insert into tb_record values('17110101','O924.01','2019-05-25',null);
+go
+
+
+select * from tb_student
+select * from tb_inf_student
+select * from tb_bibliography
+select * from tb_book
+select * from tb_record
+
+--select name,author,category from tb_bibliography
+--where author,category = (select author,category from tb_bibliography where name='管理信息系统实用教程(第3版)')
+		
+		
+--游标练习
+--- 创建学生游标，该游标包含(学生姓名,兴趣爱好,生源地，荣誉总数)
+declare student cursor scroll for(select name,hobby,ori_loca,prize from tb_student ts inner join tb_inf_student ti on ts.stu_num=ti.stu_num)
+declare @names varchar(10),@hobbys varchar(10),@loca varchar(10),@prizes int
+
+open student 
+fetch first from student into @names,@hobbys,@loca,@prizes
+while(@@FETCH_STATUS=0)
+begin 
+  fetch next from student into @names,@hobbys,@loca,@prizes
+  print @names+','+@hobbys+','+@loca+','+convert(varchar(20),@prizes)
+end
+
+close student
+
+--- 循环遍历161开头的学生信息
+declare stu_information cursor scroll for(select * from tb_student where stu_num like '161%')
+declare @num int,@name varchar(10),@gender int,@birth date,@school varchar(10),@major varchar(20)
+
+open stu_information
+fetch first from stu_information into @num,@name,@gender,@birth,@school,@major
+while(@@FETCH_STATUS=0)
+begin
+  fetch next from stu_information into @num,@name,@gender,@birth,@school,@major
+  print convert(varchar(2),@num)+','+@name+','+convert(varchar(2),@gender)+','+convert(varchar(20),@birth)+','+@school+','+@major
+end
+close stu_information
+
+--- 使用游标统计生源地为北京的荣誉总数
+declare loca cursor scroll for(select sum(prize) from tb_inf_student where ori_loca='北京')
+declare @locas int
+open loca
+fetch first from loca into @locas
+while(@@FETCH_STATUS=0)
+begin
+   fetch next from loca into @locas
+   print @locas
+end
+close loca
+
+--- 合理使用游标和事务，让5-1号前借书的学生将图书归还
+declare books cursor scroll for(select * from tb_record where borrow_time<'2019-05-01' and return_time is null)
+open books
+begin transaction
+
+  declare @nums int=0
+  update tb_record set return_time=GETDATE() where borrow_time<'2019-05-01'and return_time is null
+  set @nums += @@ERROR
+
+print @nums
+if @nums>0
+	begin
+		print '未归还'
+		rollback transaction
+	end
+else
+	begin
+		print '已归还'
+		commit transaction
+	end
+
+
+close books
+select * from tb_record
+```
diff --git "a/09\351\231\210\347\203\275\346\235\260/\347\254\224\350\256\260/9.20\346\270\270\346\240\207.md" "b/09\351\231\210\347\203\275\346\235\260/\347\254\224\350\256\260/9.20\346\270\270\346\240\207.md"
new file mode 100644
index 0000000..f9040cf
--- /dev/null
+++ "b/09\351\231\210\347\203\275\346\235\260/\347\254\224\350\256\260/9.20\346\270\270\346\240\207.md"
@@ -0,0 +1,72 @@
+## 游标
+
+（1）静态游标(Static)：在操作游标的时候，数据发生变化，游标中数据不变 （2）动态游标(Dynamic)：在操作游标的时候，数据发生变化，游标中数据改变，默认值。 （3）键集驱动游标(KeySet)：在操作游标的时候，被标识的列发生改变，游标中数据改变，其他列改变，游标中数据不变。
+
+**创建游标：**
+
+```
+--1.创建游标(Scroll代表滚动游标，不加Scroll则是只进的，只能支持fetch next)
+declare <游标名> cursor scroll for select stuname from stuinfo
+```
+
+**打开游标：**
+
+```
+open  <游标名>
+```
+
+**关闭游标：**
+
+```
+close <游标名>
+```
+
+**删除游标：**
+
+```
+deallocate <游标名>
+```
+
+# 提取数据
+
+## 第一行
+
+fetch **first** from 游标名
+
+## 最后一行
+
+fetch **last** from 游标名
+
+## 第n行
+
+fetch **absolute** n from 游标名
+
+## 当前位置第n行
+
+fetch **relative** n from 游标名
+
+## 当前位置下一行
+
+fetch **next** from 游标名
+
+## 当前位置的上一行
+
+fetch **prior** from 游标名
+
+## 可进行填充后打印输出
+
+# 游标指向某行多列数据
+
+declare 游标名 cursor [scroll] for (select 列1，列2，列3，列4 from 表名)
+
+把数据赋给变量
+
+fetch **first** from 游标名 into 变量1，变量2，变量3，变量4
+
+# @@FETCH_STATUS
+
+@@FETCH_STATUS=0,提取成功
+
+@@FETCH_STATUS=-1,提取失败
+
+@@FETCH_STATUS=-2,行不存在
-- 
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