Oracle 游标
--select * from student;
--delete from student where sid>=4;

--delete from "SYSTEM"."STUDENT";
--SELECT * FROM "SYSTEM"."STUDENT";
/*
--插入30条记录
SET SERVEROUTPUT ON
DECLARE
I INT:=0;
begin
FOR I IN 1..30 LOOP
INSERT INTO "SYSTEM"."STUDENT" (SID,SNAME,SDATE) VALUES(I,'FRJ'||TO_CHAR(I),SYSDATE);
END LOOP;
commit;
end;
*/

--采用游标查询出sid>2的纪录的 sid;
declare
tempsid system.student.sid%type; --定义一个变量,它的数据类型与student表中的sid类型相同
cursor myCursor --定义游标
is --游标所执行的操作
select * from system.student
where sid>2;
selCursorRecord myCursor%rowtype; --游标实例化
begin
tempsid:=0;
open myCursor; --打开游标
/*if myCursor%isopen then --测试游标是否打开,打开则返回真,如果没有打开游标就使用fetch语句将提示错误.
fetch myCursor into selCursorRecord;
dbms_output.put_line(to_char(' sid: '|| selCursorRecord.sid));
else
dbms_output.put_line(to_char(' 游标没有打开.'));
end if;
*/
/*
while myCursor%isopen loop
fetch myCursor into selCursorRecord;
dbms_output.put_line(to_char(' sid: '|| selCursorRecord.sid));
end loop;
--dbms_output.put_line(' 游标中所有的数据行数.'|| to_char(myCursor%rowcount));
*/
loop --这一种循环结构比上种更为准确
tempsid:=tempsid+1;
exit when myCursor%notfound ;
fetch myCursor into selCursorRecord;
dbms_output.put_line(to_char(' sid: '|| selCursorRecord.sid || ' rows ' ||tempsid));
end loop;
dbms_output.put_line(' 游标中所有的数据行数.'|| to_char(myCursor%rowcount)) ; --获取游标中的数据行数
close myCursor; --关闭游标
end;




















































【推荐】编程新体验,更懂你的AI,立即体验豆包MarsCode编程助手
【推荐】凌霞软件回馈社区,博客园 & 1Panel & Halo 联合会员上线
【推荐】抖音旗下AI助手豆包,你的智能百科全书,全免费不限次数
【推荐】博客园社区专享云产品让利特惠,阿里云新客6.5折上折
【推荐】轻量又高性能的 SSH 工具 IShell:AI 加持,快人一步
· 一个奇形怪状的面试题:Bean中的CHM要不要加volatile?
· [.NET]调用本地 Deepseek 模型
· 一个费力不讨好的项目,让我损失了近一半的绩效!
· .NET Core 托管堆内存泄露/CPU异常的常见思路
· PostgreSQL 和 SQL Server 在统计信息维护中的关键差异
· DeepSeek “源神”启动!「GitHub 热点速览」
· 我与微信审核的“相爱相杀”看个人小程序副业
· 微软正式发布.NET 10 Preview 1:开启下一代开发框架新篇章
· 如何使用 Uni-app 实现视频聊天(源码,支持安卓、iOS)
· C# 集成 DeepSeek 模型实现 AI 私有化(本地部署与 API 调用教程)