From 7526e93606edddeac11106d995cab023f3f337ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9B=BE=E5=BE=B7=E6=A3=AE?= <1500225483@qq.com>
Date: Thu, 6 Oct 2022 01:38:27 +0000
Subject: [PATCH 1/2] =?UTF-8?q?=E6=96=B0=E5=BB=BA=202022-9-30-=E6=B8=B8?=
 =?UTF-8?q?=E6=A0=87?=
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---
 .../2022-9-30-\346\270\270\346\240\207/.keep"                     | 0
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 create mode 100644 "47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/.keep"

diff --git "a/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/.keep" "b/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/.keep"
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index 0000000..e69de29
-- 
Gitee


From 553e6c17b1b4c3f5b66c2d709ae1695d4fd31a0b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9B=BE=E5=BE=B7=E6=A3=AE?= <1500225483@qq.com>
Date: Thu, 6 Oct 2022 01:38:45 +0000
Subject: [PATCH 2/2] =?UTF-8?q?=E6=9B=BE=E5=BE=B7=E6=A3=AE?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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Signed-off-by: 曾德森 <1500225483@qq.com>
---
 .../\344\275\234\344\270\232/SQLQuery2.sql"   | 56 +++++++++++++++++++
 .../\346\270\270\346\240\207.md"              | 56 +++++++++++++++++++
 2 files changed, 112 insertions(+)
 create mode 100644 "47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\344\275\234\344\270\232/SQLQuery2.sql"
 create mode 100644 "47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\347\254\224\350\256\260/\346\270\270\346\240\207.md"

diff --git "a/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\344\275\234\344\270\232/SQLQuery2.sql" "b/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\344\275\234\344\270\232/SQLQuery2.sql"
new file mode 100644
index 0000000..af126a8
--- /dev/null
+++ "b/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\344\275\234\344\270\232/SQLQuery2.sql"
@@ -0,0 +1,56 @@
+��3��ʹ���α�ʵ�ּ�н����
+--�����α�
+declare cur_id cursor scroll for select PeopleId from People
+--���α�
+open cur_id
+--��ȡ����
+declare @id int, @money money = 1000
+fetch first from cur_id into @id
+while (@@fetch_status = 0)
+	begin
+		update People set PeopleSalary += @money where PeopleId = @id
+		fetch next from cur_id into @id
+	end
+--�ر��α�
+close cur_id
+select * from People
+go
+
+--��4:ʹ���α�ɾ�������Ա��
+select * from People
+--����
+declare cur_id cursor scroll for select PeopleId,PeopleSalary from People
+--��
+open cur_id
+--��ȡ
+declare @id int, @money money
+fetch first from cur_id into @id,@money
+while(@@FETCH_STATUS = 0)
+	begin
+		if(@money < 10000)
+		begin
+			delete People where PeopleId = @id
+			fetch next from cur_id into @id,@money
+		end
+		else
+			fetch next from cur_id into @id,@money
+	end
+close cur_id
+select * from People
+go
+--ʹ���α� ʵ��:���A����B����ID�ֶ�ֵ��ͬ����ô��B���е�ʡ�ݣ����� �޸ij���A���еij���һ�£�������
+
+declare cur_id cursor scroll for select A.* from A inner join B on A.id = B.id
+deallocate cur_id
+open cur_id
+declare @id int , @id1 int,@Province varchar(10),@City varchar(10)
+fetch first from cur_id into @id,@Province,@City
+while(@@FETCH_STATUS = 0)
+	begin
+			update B set B.Province = @Province , B.City = @City where B.id = @id
+			fetch next from cur_id into @id,@Province,@City
+	end
+		
+close cur_id
+select * from A
+select * from B
\ No newline at end of file
diff --git "a/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\347\254\224\350\256\260/\346\270\270\346\240\207.md" "b/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\347\254\224\350\256\260/\346\270\270\346\240\207.md"
new file mode 100644
index 0000000..fbf2dd4
--- /dev/null
+++ "b/47\346\233\276\345\276\267\346\243\256/2022-9-30-\346\270\270\346\240\207/\346\233\276\345\276\267\346\243\256/\347\254\224\350\256\260/\346\270\270\346\240\207.md"
@@ -0,0 +1,56 @@
+## 1.1游标的基本概念
+
+游标是一种处理数据的方法，具有对结果集进行逐行处理的能力
+
+## 1-2 游标的实现功能及使用步骤
+
+**游标的实现功能**
+
+允许对 SELECT 返回的表中的每一行进行相同或不同的操作，而不是一次对整个结果集进行同一种操作； 从表中的当前位置检索一行或多行数据； 游标允许应用程序对当前位置的数据进行修改、删除的能力； 对于不同用户对结果集包含的数据所做的修改，支持不同的可见性级别； 游标的使用步骤
+
+- 创建游标
+
+```
+declare 游标名 cursor scroll for select查询语句
+
+游标分为局部游标和全局游标两种，local表示局部游标，global表示全局游标(默认值，可以省略)。当指定 forward_only(默认值，可以省略)时，游标是只进的，也就是说只能从头到尾地提取记录，如果需要在行之间来回跳跃，需要指定为scroll。
+```
+
+- 打开游标
+- 读取内容
+- 关闭游标
+- 释放游标（删除）
+
+```
+deallocate (游标名)
+```
+
+**提取数据操作：**
+
+```
+fetch first from <游标名> --结果集的第一行
+fetch last from <游标名>  --最后一行
+fetch absolute 1 from <游标名> --从游标的第一行开始数，第n行。
+fetch relative 3 from <游标名> --从当前位置数，第n行。
+fetch next from <游标名> --当前位置的下一行
+fetch prior from <游标名> --当前位置的上一行
+```
+
+**游标分为静态游标和动态游标，静态游标的数据是固定的，不会因为数据表的改变而改变；动态游标的数据是随着数据表变化而变化的，游标默认是动态游标**
+
+```
+DECLARE @id INT , @name NVARCHAR(50)    --声明变量，需要读取的数据
+DECLARE cur CURSOR 				--去掉STATIC关键字即可
+FOR
+    SELECT  * FROM    #T
+OPEN cur								--打开游标
+FETCH NEXT FROM cur INTO @id, @name     --取数据
+WHILE ( @@fetch_status = 0 )            --判断是否还有数据
+    BEGIN
+        SELECT '数据: ' + RTRIM(@id) + @name
+		UPDATE #T SET name='测试' WHERE id=4  --测试静态动态用
+        FETCH NEXT FROM cur INTO @id, @name   --这里一定要写取下一条数据
+    END
+CLOSE cur								--关闭游标
+DEALLOCATE cur
+```
\ No newline at end of file
-- 
Gitee